WRIST TERMINOLOGY AS DEFINED BY THE INTERNATIONAL …sportho.net/Anatomical/UpperLimb/wrist/Terminology.pdfTHE JOURNAL OF BONE & JOINT SURGERY · JBJS.ORG VOLUME 84-A · SUPPLEMENT

TH E JO U R NA L OF BONE & JOINT SURGER Y · JBJS .ORG

VO LU M E 84-A · SUPPLEMENT 1 · 2002WR IS T: TER MINOLO G Y AND DEFINIT ION

WRIST TERMINOLOGY AS DEFINED BY THE INTERNATIONAL WRIST INVESTIGATORS’ WORKSHOP (IWIW)

GILULA LA, MANN FA, DOBYNS JH, YIN Y, AND IWIW TERMINOLOGY COMMITTEE*

ADAPTIVE CARPUS (FIGURE 1)

SYNONYM: none

CLINICAL: NA

RADIOLOGIC: a carpal malalignment usually identified by a dorsalor volar tilt of the lunate caused by an extracarpal osseous abnormal-ity, usually a distal radial malunion without ligament tears

COMMENTS: 1) every carpus must adjust in some way to alter-ations of the radius articular surface, the ulnar head position, and

the shape or size of the carpal bones even if all of its ligaments are in-tact. Although these alterations of the osseous elements may disruptthe ligament anchorage, may be accompanied by ligament damage,or may secondarily develop ligament attenuation, they often beginas a normal carpus. 2) The carpus may be malaligned between thetwo rows or remain aligned within itself, while translating at the ra-diocarpal level to a new position (usually dorsal, sometimes volar,even ulnar or radial). 3) This definition refers to an extracarpal, notan intracarpal, problem. If the malalignment is due to an intracarpalproblem, then the case falls into a CID, CIND, or CIC category andwould not fit into the category of an adaptive carpus as describedhere. Any adaptive carpus, by definition, can be solved by an extra-carpal intervention that does not require surgery on the carpus.However, with time an adaptive carpus may degenerate to a pointthat the intrinsic ligaments fail and a secondary CID pattern (an in-tracarpal problem) is established.

CODE: Clinical Conditions: Residuals of Injuries (IIIC)**

REFERENCES:1. Dobyns JH, Linscheid RL. Complications of treatment of fractures and disloca-

tions of the wrist. In: Epps CH Jr, editor. Complications in orthopaedic surgery. Vol 2. Philadelphia: JB Lippincott; 1978. p 271-352.

2. Cooney WP 3rd, Dobyns JH, Linscheid RL. Complications of Colles’ fractures. J Bone Joint Surg Am. 1980;62:613-9.

3. Brahin B, Allieu Y. [Compensatory carpal malalignments]. Ann Chir Main. 1984;3:357-63. French.

4. Allieu Y. [Carpal instability. General therapeutic principles]. Ann Chir Main. 1984;3:364-7. French.

5. Taleisnik J, Watson HK. Midcarpal instability caused by malunited fractures of the distal radius. J Hand Surg [Am]. 1984;9:350-7.

6. Saffar P. Carpal injuries: anatomy, radiology, current treatment. Paris: Springer; 1990.

7. Dobyns JH, Berger RA. Dislocations of the carpus. In: Chapman MW, Madison M, editors. Operative orthopedics. 2nd ed, vol 2. Philadelphia: JB Lippincott; 1993. p 1289-305.

ANATOMIC NEUTRAL (FIGURE 2)

SYNONYM: zero-position

CLINICAL: the wrist placed in neutral (zero) position of extension-flexion, radial-ulnar deviation, and forearm pronation-supination.The third metacarpal is positioned collinear with the radius.

RADIOLOGIC: NA

COMMENTS: 1) PA radiographs of this position are facilitated byflexing the elbow to 90° and abducting the shoulder to 90°. 2) SeeLATERAL VIEW and POSTEROANTERIOR VIEW.

CODE: Radiologic: Positions (IA)

REFERENCES:1. Palmer AK. The distal radioulnar joint. Orthop Clin North Am. 1984;15:

321-35.

2. Bowers WH. Problems of the distal radioulnar joint. Advances in Orthopedic Surgery. 1984;7:289.

Fig. 1

ADAPTIVE CARPUS-ADAPTIVE DISI: the distal articular surface

of the radius is inclined 30° dorsally from an old impacted

distal radius fracture. The lunate is tilted dorsally to account

for dorsal inclination of the distal radius, while the capitate is

in neutral position following the position of the metacarpals

with the hand. Changes in the carpal alignment creates a cap-

itolunate angle of approximately 30° and a scapholunate

angle of 85°. The increased scapholunate angle creates a

DISI (dorsal intercalated segmental instability) configuration.

*See Appendix C.**See Appendix B.



ANCHOR see TETHER

ANTERIOR see PALMAR or VOLAR

ANTEROPOSTERIOR (AP) VIEW OR PROJECTION (FIGURE 3)

SYNONYMS: coronal, frontal, palm-to-dorsum, volar-to-dorsal, APprojection, AP position

CLINICAL: NA; see RADIOLOGIC

Fig. 2a

ANATOMIC NEUTRAL (ZERO POSITION): a) posteroanterior (PA)

position and b) lateral position. The wrist is placed so that there is

no flexion, extension, or radial or ulnar deviation. The third meta-

carpal is positioned collinear with the radius. In the PA position

(see also Fig 4B) the elbow is elevated to the shoulder height, and

in the lateral position the elbow is adducted to the patient’s side.

(Reprinted with permission from Gilula LA, Yin Y, editors. Imaging

of the wrist and hand. Philadelphia: WB Saunders; 1996. p 226.

Fig 9-1, A and B.)

Fig. 3a

ANTEROPOSTERIOR (AP) VIEW OR PROJECTION: a) clinical view for an AP view of the hand and wrist combined: the x-ray beam enters the anterior (palmar) surface of the hand/wrist at the level of the third metacarpal head and exits the posterior (dorsal) surface of the hand/wrist to expose the x-ray film, which is posterior to the hand/wrist. For a wrist view, the central ray would be centered in the middle of the wrist at the level of the capitate head. b) On the AP radiographic view of the hand and wrist, the ulnar styloid (barely included on this figure) is typi-cally more radial in position than with the PA view and commonly over-lies the central portion of the distal ulna. Also, the scapholunate and lunotriquetral joints are commonly better profiled on the AP than on the PA view. (Reprinted with permission from Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saunders; 1996. p 98. Fig 5-5, A and B.)

Fig. 2b

Fig. 3b



RADIOLOGIC: radiologic beam enters the anterior and exits theposterior surface of a body part; the radiographic film is on the pos-terior surface of the radiographed body part.

COMMENTS: none

CODE: Radiologic: Views (ID)

REFERENCES:1. Radiology textbooks

2. Yin Y, Mann FA, Gilula LA. Positions and techniques. In: Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saunders; 1996. p 93-158.

ARCS see CARPAL ARCS

AXIAL CARPAL DISLOCATION see LONGITUDINALCARPAL DISLOCATION

AXIAL CARPAL FRACTURE-DISLOCATION seeLONGITUDINAL CARPAL FRACTURE-DISLOCATION

AXIAL CARPAL INSTABILITY see LONGITUDINALCARPAL INSTABILITY

AXIAL CARPAL SUBLUXATION see LONGITUDINALCARPAL SUBLUXATION

AXIAL PLANE see TRANSVERSE PLANE

BACK see POSTERIOR

BALL CATCHER’S VIEW OR PROJECTION (FIGURE 4)

SYNONYM: Norgaard view

CLINICAL: NA

RADIOLOGIC: the hand or hands are placed palm up, with thumbs

elevated approximately 30-45° off the film cassette, and the dorsal as-pect of the hypothenar eminences flush on the radiographic cassette.The central ray enters the midportion of the hand if one hand is ra-diographed or the space between both hands if both hands are radio-graphed simultaneously.

COMMENTS: a position of the wrist and hand to project the palmarulnar aspect of hand and wrist bones in more detail. This projectionhas been used to look for erosions seen in arthritis but could be usedwhenever the ventral ulnar aspects of these bones must be profiled orwhen a different oblique projection of the bones of the hands andwrists is desired.


REFERENCES: 1. Norgaard F. Earliest roentgenological changes in polyarthritis of the rheumatoid

type: rheumatoid arthritis. Radiology. 1965;85:325-9.

2. Norgaard F. Earliest roentgen changes in polyarthritis of the rheumatoid type. Continued investigations. Radiology. 1969;92:299-303.

BONDED see NONDISSOCIATION

BREWERTON VIEW OR PROJECTION (FIGURE 5)

SYNONYM: none

CLINICAL: NA

RADIOLOGIC: the dorsum of the fingers are positioned flat on theradiographic cassette with the metacarpophalangeal joints flexed 45-60° and the central beam angled 15-20° from the ulnar to the radialside of the hand.

COMMENTS: this view is designed to display the metacarpopha-langeal areas of the fingers. In contrast to standard frontal and ob-lique radiographs, these views demonstrate the grooved area betweenthe collateral ligaments and the articular cartilage of the metacarpal

Fig. 4bFig. 4a

BALL CATCHER’S VIEW OR PROJECTION: a) clinical view: the hands are placed with the ulnar side of the hands on the cassette or table top with

the radial sides of the hands elevated 35-45° off the cassette in a position as to catch a ball. b) This view demonstrates the ventroulnar sides of

the hand and wrist bones in better profile than on other views. (Reprinted with permission from Gilula LA, Yin Y, editors. Imaging of the wrist and

hand. Philadelphia: WB Saunders; 1996. p 152. Fig 5-56, A and B.)



heads and, when the carpus is included, the metacarpal bases and an-gled oblique view of carpal bones.


REFERENCE:1. Brewerton DA. A tangential radiographic projection for demonstrating involve-

ment of metacarpal heads in rheumatoid arthritis. Br J Radiol. 1967;40:233-4.

CAPITATE RADIUS DISTANCE, INDEX, RATIO see CARPAL HEIGHT

CAPITOLUNATE INSTABILITY PATTERN (CLIP) (FIGURE 6)

SYNONYMS: dorsal midcarpal instability (see comment #2), mid-carpal instability

CLINICAL: a form of carpal instability manifested most obviously atthe capitolunate joint in which the clinical presentation is one ofpainful discomfort of presenting symptomatology produced by astress maneuver (by the patient or by the examiner), which may ormay not be accompanied by a clicking or snapping in the midcarpalregion. The stress maneuver, as performed by the examiner, is simi-lar to that used for radiologic demonstration. See RADIOLOGIC fordescription of stress maneuvers. See COMMENTS for controversywith CLIP.

RADIOLOGIC: dorsal displacement of the hand and distal part ofthe carpus is produced while fixing the distal part of the forearm.Longitudinal traction can be useful. Slight wrist flexion is the test po-sition, although ulnar deviation may assist or radial deviation mayhinder the ease of testing. This displacement is produced by pressingon the scaphoid tubercle or volar aspect of the midportion of the car-pus in a dorsal direction. Typically, slight capitolunate subluxationwill occur with the dorsal displacing force. These radiographic views

are obtained in the lateral position with the patient having relaxedmusculature. This test stresses both RC (radiocarpal) and MC (mid-carpal) joints and could show loss of congruity at either the radio-carpal or the capitolunate joint. The stress can be limited to themidcarpal level by including the proximal carpal row in the distalforearm fixation grip. When the test is positive, there is dorsal dis-placement of the capitate and hamate from the distal articular surfaceof the proximal carpal row (recognized by the lunate on radiographs)and occasionally a dorsal displacement of the lunate and proximalcarpal row from the fossae of the radius. However, a positive radio-logic finding must be matched by the clinical re-creation of the pa-tient’s presenting symptomatology. The opposite wrist should beexamined in the same way for comparison to see if the displacementis the same or more on the symptomatic side.

COMMENTS: 1) wide practice variation suggests the need for im-proved standardization of the performance and interpretation ofthe provocative maneuver used to identify this condition. 2) CLIP issaid by some to be a combination of dorsal radiocarpal and mid-carpal instability. However, the exact pattern of ligament tears orinsufficiency associated with this “instability” remains unclear. 3)With clinical testing, it is important to distinguish CLIP from apositive Scaphoid Shift Test (Watson Test). 4) Some people alsocheck midcarpal laxity by performing this same test with palmar-directed force applied over the dorsum of the second through thefourth carpometacarpal joints (see reference #5). With the ventraldisplacing force, the lunate will typically change its orientation toface volarly with the capitate head still remaining within the distallunate concavity. More rarely, the capitate could sublux out of thedistal lunate concavity. A positive test would occur when presentingsymptomatology is associated with this maneuver. Again, as for thedorsal-directed maneuver, the opposite wrist should be includedfor comparison.

BREWERTON VIEW OR PROJECTION: a) the dorsa of the fingers are placed flat on the table or film cassette, with the hand flexed 45-65° at the meta-

carpophalangeal (MCP) joints. The pointer designates the centering place for the central x-ray beam, which is entering the MCP joints at an angle of 15-

20° ulnar to radial. b) Good detail of the metacarpal heads with better demonstration of the ventral surfaces of the metacarpal heads is provided with

this view as compared to the routine PA or AP views of the metacarpals. (Reprinted with permission from Gilula LA, Yin Y, editors. Imaging of the wrist

and hand. Philadelphia: WB Saunders; 1996. p 104. Fig 5-11, A and B.)

Fig. 5bFig. 5a



CODE: Clinical Conditions: Sprains-Instabilities-Subluxations (IIIB)

REFERENCES:1. Louis DS, Hankin FM, Greene TL, Braunstein EM, White SJ. Central carpal

instability--capitate lunate instability pattern. Diagnosis by dynamic place-ment. Orthopaedics. 1984;7:1693-6.

2. White SJ, Louis DS, Braunstein EM, Hankin FM, Greene TL. Capitate-lunate in-stability: recognition by manipulation under fluoroscopy. AJR Am J Roentgenol. 1984;143:361-4.

3. Dobyns JH, Linscheid RL, Chao EYS, Weber ER, Swanson GE. Traumatic insta-bility of the wrist. AAOS Instr Course Lect. 1975;24:182-99.

4. Johnson RP, Carrera GF. Chronic capitolunate instability. J Bone Joint Surg Am. 1986;68:1164-76.

5. Truong NP, Mann FA, Gilula LA. II. Indications for wrist instability series and its cost-effectiveness. In: Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saunders; 1996. p 188-202.

CARPAL ANGLE (FIGURE 7)

SYNONYM: frontal carpal condyle angle

CLINICAL: the angle subtended by the proximal surfaces of theproximal carpal row as seen on the PA radiograph

RADIOLOGIC: “The carpal angle is defined by the intersection oftwo tangents, one touching the proximal contour of the scaphoid andlunate bones and the second touching the triquetrum and lunatebones.” Between 4 and 83 years of age for males and females, Cauca-sians and blacks, the angle is 116-153.5°. (See reference #1)

COMMENTS: none

CODE: Radiologic: Measurements (IE)

Fig. 6b

CAPITOLUNATE INSTABILITY PATTERN (CLIP): a) lateral wrist view with

dorsally directed stress (arrow with “S”) pushes the capitate partially

out of the lunate fossa. See Text. The wrist is still in satisfactory

lateral position as noted by the scaphopisocapitate (SPC) relation-

ship (see LATERAL VIEW). b) With stress released, a normal capitolu-

nate relationship is restored. (Reprinted with permission from Gilula

LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB

Saunders; 1996. p 215. Fig 8-15, A and B.)

Fig. 6a

Fig. 7

CARPAL ANGLE: the angle created between the two lines X and Y. X is a

line drawn tangential to the proximal cortical surfaces of the scaphoid

and lunate, and Y is the line tangent to the proximal cortices of the tri-

quetrum and lunate. (Reprinted with permission from Gilula LA, Yin Y,

editors. Imaging of the wrist and hand. Philadelphia: WB Saunders; 1996.

p 233. Fig 9-8.)



REFERENCES: 1. Harper HA, Poznanski AK, Garn SM. The carpal angle in American populations.

Invest Radiol. 1974;9:217-21.

2. Kosowicz J. The carpal sign in gonadal dysgenesis. J Clin Endocrinol Metab. 1962;22:949.

3. Kosowicz J. The roentgen appearance of the hand and wrist in gonadal dysgen-esis. AJR Am J Roentgenol. 1965;99:354.

CARPAL ARCS (FIGURE 8)

SYNONYMS: Gilula’s arcs, radiologic carpal arcs I-III, Gilula’s lines

CLINICAL: NA

RADIOLOGIC: three smooth arcs with changing radii normally can bedrawn along surfaces of carpal bones seen on radiographs when thehand is supinated or pronated and is in neutral position (see COM-MENTS). 1) Arc I represents the smooth curvature or arc that nor-mally defines the proximal convex cortical surfaces of the scaphoid,lunate, and triquetrum; 2) Arc II represents the smooth arc that definesthe distal cortical concavities of the scaphoid, lunate, and triquetrum;and 3) Arc III refers to the smooth arc that outlines the proximal corti-cal convexities of the capitate and hamate. (See COMMENTS.)

COMMENTS: 1) the arcs can be evaluated only in the neutral PA orAP position, which is defined as the situation when the long axis ofthe third metacarpal is coaxial with the long axis of the distal radius.2) Any break in one of the arcs implies an abnormality at the brokensite. Exceptions are: (a) at each joint, the edge of the adjacent boneshave a more acute curvature; therefore, only the major curvatures ofbones should be used; (b) a carpal arc is not applicable when one car-pal bone is congenitally smaller than the adjacent carpal bone; e.g.,the triquetrum may be smaller in its proximal-distal dimension thanthe adjacent lunate, resulting in a normal break in Arc I and a normalArc II at the lunotriquetral joint; and (c) with a prominent hamatefacet (distal ulnar concavity) of the lunate described by Viegas as thetype II lunate, Arc II may not be smooth at the lunotriquetral jointand Arc III may also have an offset at the capitohamate articulation.3) Arcs I and II commonly will be broken normally at the scapholu-nate and lunotriquetral joints with radial and ulnar deviation. (Seereference #4.)

CODE: Radiologic: Measurements (IE); Anatomic: Carpal (IID)

REFERENCES:1. Dobyns JH, Linscheid RL, Chao EYS, Weber ER, Swanson GE. Traumatic insta-

bility of the wrist. AAOS Instr Course Lect. 1975;24:182-99.

2. Gilula LA. Carpal injuries: analytic approach and case exercises. AJR Am J Roentgenol. 1979;133:503-17.

3. Viegas SF, Wagner K, Patterson R, Peterson P. Medial (hamate) facet of the lu-nate. J Hand Surg [Am]. 1990;15:564-71.

4. Peh WC, Gilula LA. Normal disruption of carpal arcs. J Hand Surg [Am]. 1996;21:561-6.

CARPAL BOSS (FIGURE 9)

SYNONYMS: os styloideum, carpe bossu, dorsal boss

CLINICAL: an osseous prominence at the second and/or third car-pometacarpal joints

RADIOLOGIC: the carpal boss may be produced by one of four enti-ties: a separate bone [1) os styloideum or 2) ununited fracture], 3)osteophyte (osteoarthritis), or 4) osseous prominence (exostosis) atthe second and/or third CMC.

COMMENTS: 1) strictly speaking, the os styloideum is not identicalto the term “carpal boss.” A carpal boss may exist because of a varietyof conditions as described under “radiologic” and is not necessarily

due only to the os styloideum. 2) Usually fluoroscopically obtainedspot views can serve best with plain radiography to determine whichof the above causes exists for the carpal boss (see CARPAL BOSSVIEW). 3) CT scans or complex motion tomography may be neces-sary to fully clarify the anatomic cause of the dorsal boss.

CODE: Anatomic: Radial (IIA)

REFERENCE:1. see CARPAL BOSS VIEW

Fig. 8a

CARPAL ARCS: a) on this PA neutral view (no radial or ulnar

deviation of the carpus), Arc 1 is a smooth arc outlining the

proximal surfaces of the scaphoid, lunate, and triquetrum. Arc

2 is a smooth arc that outlines the distal surfaces of these

same three carpal bones, and Arc 3 outlines the proximal sur-

faces of the capitate and hamate. b) When the proximal-distal

dimension of the triquetrum is less than the adjacent surface

of the lunate (see arrows), Arc 1 can normally be broken at the

lunotriquetral joint. With a type II lunate (with a large hamate

articulating facet of the lunate), Arcs 2 and 3 can also be bro-

ken normally at the lunotriquetral and capitohamate joints.

(Reprinted with permission from Gilula LA, Yin Y, editors. Imag-

ing of the wrist and hand. Philadelphia: WB Saunders; 1996.

p 296. Fig 11-3, A and C.)

Fig. 8b



CARPAL BOSS VIEW OR PROJECTION (FIGURE 10)

SYNONYM: carpal boss projection

CLINICAL: NA

RADIOLOGIC: two different tangential projections have been de-scribed: lateral or slightly supinated off-lateral, and the carpal bridgeview. 1) With the off-lateral projection, the wrist is positioned in flex-ion and slight supination (off lateral), so that the dorsal boss projectsoff the underlying carpometacarpal joints. The central ray of the x-raybeam is passed through the carpal boss perpendicular to the cassette.Twenty to thirty degrees of angulation toward the fingers or similarulnar deviation of the wrist may aid in demonstration of the boss orseparate ossicle. 2) The carpal bridge view is obtained by passing anx-ray beam tangent to the dorsum of the carpus with the wrist palmarflexed approximately 90° or maximally flexed. The dorsum of thehand is placed directly on the cassette. The central beam passes tan-gent to the carpal boss at approximately 45° to the cassette.

COMMENTS: the off-lateral projection is the more reliable means todemonstrate the carpal boss and its anatomic structure (see CARPALBOSS: COMMENTS).


REFERENCES: 1. Conway WF, Destouet JM, Gilula LA, Bellinghausen HW, Weeks PM. The carpal

boss: an overview of radiographic evaluation. Radiology. 1985;156:29-31.

2. Kaulesar-Sukul DM, Steinberg PJ, Lichtveld PL. The carpal boss. Neth J Surg. 1986;38:90-2.

3. Cuono CB, Watson HK. The carpal boss: surgical treatment and etiological con-siderations. Plast Reconstr Surg. 1979;63:88-93.

4. Hultgren T, Lugnegard H. Carpal boss. Acta Orthop Scand. 1986;57:547-50.

CARPAL COLLAPSE see COLLAPSE DEFORMITY

CARPAL HEIGHT, INDEX, AND RATIO (FIGURE 11)

SYNONYM: none

CLINICAL: see RADIOLOGIC

RADIOLOGIC: carpal height is a radiologic concept to aid in thequantification of carpal collapse. (1) CARPAL HEIGHT (see refer-ences #4 and #5) is defined as the distance from the base of the third

Fig. 9

CARPAL BOSS: large bone

prominences (arrowheads)

project dorsally off the junc-

tion of the second and third

carpometacarpal joints.

(Reprinted with permission

from Gilula LA, Yin Y, editors.

Imaging of the wrist and

hand. Philadelphia: WB

Saunders; 1996. p 527.

Fig 20-8A.)

Fig. 10a

CARPAL BOSS VIEW OR PROJECTION: a) this is accomplished with the

ulnar side of the wrist on the cassette or table, with ulnar deviation of

the wrist and enough supination to make the dorsal boss project dor-

sal to the adjacent metacarpal bases. Positioning for the central x-ray

beam is indicated with the pointer. b) A separate ossicle, the os styloid-

eum (arrow), is the cause for the dorsal boss in this case. (Reprinted

with permission from Gilula LA, Yin Y, editors. Imaging of the wrist and


Fig. 10b



metacarpal to the subchondral sclerotic line of the distal radial artic-ular surface as measured along the axis extended from the thirdmetacarpal. The mean has been measured as 33.8 mm (26.4-40.5mm) by Schuind et al. Another way to measure carpal height, whichis believed to be more precise and reliable by some experts than thatmentioned in references #4 and #5, is to measure the shortest dis-tance between the proximal pole of the capitate and the radius, theCAPITATE RADIUS DISTANCE (CRD) or index (see reference #6).This is determined by comparing this distance between both wrists ofthe same individual or the same wrist on subsequent follow-up ex-aminations. Normally, comparing this distance between wrists pro-duces a ratio of 0.99 with a standard deviation of 0.034 and a range of0.92-1.07. The authors (see reference #6) state that “a ratio of the newand old CR distances of the same hand which is lower than 0.95(lower rounding error limit) should be considered to be significant.”(2) The CARPAL HEIGHT RATIO (see references #1, #3, and #4) isobtained by dividing the carpal height (Lb), measured as the distancefrom the third metacarpal base to the subchondral sclerotic line ofthe distal radial articular surface, by the length of the third metacar-pal (La): Lb/La = 0.54 ± 0.03. An “ALTERNATE CARPAL HEIGHTRATIO” (see reference #2) is obtained by dividing carpal height (L2)by the capitate length (L1), measured as the distance between the in-tersection point of the capitate articular facets for the second andthird metacarpals and the proximal subchondral osseous cortex ofthe capitate along the line that passes through the center of the capi-tate head: L2/L1 = 1.57 ± 0.05. (3) The CARPAL HEIGHT INDEX(see reference #1), which corrects for differences in body habitus, is

obtained by dividing the carpal height ratio of the diseased hand bythat of the normal hand (1.00 ± 0.015).

COMMENTS: 1) when making important surgical decisions based oncarpal height, the carpal height index can become valuable to see whatcould be normal variant by seeing what is actually present in theasymptomatic opposite wrist of the same individual. 2) Reliance uponstructures within the field of collapse is inherently less reliable than usingstructures outside the problem area; however, the frequent lack of in-clusion of metacarpals on radiographs of the wrist make the alternatesystem for determining the alternate carpal height ratio quite useful.


REFERENCES:1. Stahelin A, Pfeiffer K, Sennwald G, Segmuller G. Determining carpal collapse:

an improved method. J Bone Joint Surg Am. 1989;71;1400-5.

2. Nattrass GR, King GJ, McMurtry RY, Brant RF. An alternative method for deter-mination of the carpal height ratio. J Bone Joint Surg Am. 1994;76:88-94.

3. Schuind FA, Linscheid RL, An K-N, Chao EY. A normal database of posteroante-rior roentgenographic measurements of the wrist. J Bone Joint Surg Am. 1992;74:1418-29.

4. Youm Y, McMurtry RY, Flatt AE, Gillespie TE. Kinematics of the wrist. I. An ex-perimental study of radial-ulnar deviation and flexion-extension. J Bone Joint Surg Am. 1978;60:423-31.

5. McMurtry RY, Youm Y, Flatt AE, Gillespie TE. Kinematics of the wrist. II. Clinical applications. J Bone Joint Surg Am. 1978;60:955-61.

6. Zdravkovic V, Sennwald GR. A new radiographic method of measuring carpal collapse. J Bone Joint Surg Br. 1997;79:167-9.

Fig. 11b

CARPAL HEIGHT AND CARPAL HEIGHT RATIO: a) carpal height is mea-

sured by the line Lb, which is the distance from the base of the third

metacarpal to the distal radius articular surface, measured along the

central axis of the third metacarpal. La (from the head to the base of the third metacarpal) is the length of the third metacarpal. L b/La is 0.54 ± 0.03

for the carpal height ratio. b) An alternate carpal height ratio can be determined by dividing the carpal height (L2) by the length of the capitate (L1) for

a ratio of 1.57 ± 0.05. L1 is determined by the longest length of the capitate starting at a point on the distal cortex of the capitate at the junction

between the bases of the second and third metacarpal bones. (Reprinted with permission from Mann FA, Wilson AJ, Gilula LA. Radiographic evalua-

tion of the wrist: what does the hand surgeon want to know? Radiology. 1992;184:15-24. Fig 1, A and B.)

Fig. 11a



CARPAL INSTABILITY COMBINED OR COMPLEX (CIC) (FIGURE 12)

SYNONYM: none

CLINICAL: a carpal instability characterized by derangement bothwithin and between carpal rows

RADIOLOGIC: see CLINICAL

COMMENTS: 1) the specific malalignments, dissociations, sublux-ations, dislocations, and fractures that compose the abnormalityshould be named. 2) Perilunate instabilities as SLD (scapholunatedissociation) or TLD (triquetrolunate or lunotriquetral dissociation)alone are CIDs and are not CICs unless they have an additional com-ponent of another category, e.g., ulnar translation, which is a radio-carpal instability deformity or perilunate dislocation. Longitudinal(axial) carpal instabilities are seldom seen as subluxations only,which would qualify as CID; they usually demonstrate a dislocationcomponent, indicating rupture of both extrinsic and intrinsic liga-ments, which make them CICs, e.g., dorsal CMC dislocation, dorsaldislocation of the capitate, or ulnar translation of the carpus. 3) CICrepresents a combination of two or more well-defined patterns as acombination of scapholunate and lunotriquetral instabilities (2CIDs) or SLD plus ulnar translocation (a CID plus a CIND). Inter-estingly, many CIDs become CICs as gradual attenuation or addi-

tional injury involves the extrinsic support systems surrounding theCID lesion. 4) It is common for both dissociative and nondissociativetypes of injury to be present in the same wrist, which fits the descrip-tion of CIC. It is now recognized that most CIDs and many CINDseither become CICs or have elements of CIC from the beginning.Knowing how many elements of instability are present is fundamen-tal in selecting a surgical method for control of the instability. 5) LTdissociation is seldom evident as widening at this joint. Indeed thispathology is usually shown by an abnormal translation between thetriquetrum and lunate, but not by a “gap.” 6) “The term ‘instability’has been frequently understood as a synonym of ‘malalignment.’ Ac-cording to this view, a wrist is categorized as unstable when there is asporadic or permanent alteration of the sagittal and/or frontal align-ment of the carpal bones beyond the limits of what is considered nor-mal. From this perspective, instability would be a radiographicdiagnosis. Such a concept of instability has been criticized by differ-ent authors who claim that an alteration of the carpal alignmentshould not always be considered pathologic” (see reference #7).

CODE: Clinical Conditions: Mixed Bag (IIID)

REFERENCES:1. Cooney WP III, Garcia-Elias M, Dobyns JH, et al. Anatomy and mechanics of

carpal instability. Surg Rounds Orthop. 1989;9:15-24.

Fig. 12bFig. 12a

CARPAL INSTABILITY COMBINED OR COMPLEX (CIC): a) this PA view shows scapholunate dissociation, ventral tilting of the scaphoid (foreshortened

shape) and lunate (triangular shape), and offset of Arc 1 at the lunotriquetral joint. The scaphoid fossa is deepened from erosive change, and

osteoarthritis involves the radial styloid and scaphoid (the scaphoid tubercle with its osteophyte is not shown here). The proximal end of the capitate

is flattened and the capitolunate joint is narrowed. b) On the lateral view, a satisfactory SPC relationship is maintained (see LATERAL VIEW). The

scaphoid, lunate, and triquetrum are tilted toward the palm, but these are tilted in a dissociated pattern as emphasized on the PA view. The lunate is

displaced dorsally, riding on the dorsal rim of the radius, and the scaphoid is riding on the ventral rim of the radius. A slight concavity in the dorsal

rim of the radius proximal to the lunate indicates that this portion of the distal radius has reformed from longstanding articulation between the radius

and the dorsally displaced lunate. Osteophytes involve the distal dorsal radius indicative of radiocarpal osteoarthritis. All these findings demonstrate

radiocarpal, scapholunate, and lunotriquetral dissociation with VISI configuration (capitolunate angle of approximately 55° and scapholunate angle of

about 20°). Therefore, abnormalities exist at the radiocarpal and midcarpal levels as well as within the proximal carpal row.



2. Cooney WP, Dobyns JH, Linscheid RL. Arthroscopy of the wrist: anatomy and classification of carpal instability. Arthroscopy. 1990;6:133-40.

3. Linscheid RL, Dobyns JH. Carpal instability. Curr Orthop. 1989;3:106-14.

4. Wilson AJ, Mann FA, Gilula LA. Imaging the hand and wrist. J Hand Surg [Br]. 1990;15:153-67.

5. Dobyns JH. Carpal instability: a review. In: Nakamura R, Linscheid RL, Miura T, editors. Wrist disorders. New York: Springer; 1992. p 239-46.

6. Dobyns JH, Berger RA. Dislocations of the carpus. In: Chapman MW, Madison M, editors. Operative Orthopedics. 2nd ed, vol 2. Philadelphia: JB Lippincott; 1993. p 1289-305.

7. Garcia-Elias M, Berger RA, Horii E, Kauer JMG, Lanz U, Rongières M, Ryu J, Sennwald GR, Viegas SF. Definition of carpal instability. Anatomy and Biome-chanics Committee of the International Federation of Societies for Surgery of the Hand. 2nd ed. Barcelona, Spain: Institut Kaplan; Feb 1999.

CARPAL INSTABILITY COMBINED-PERILUNAR (CIC-PLD) see PERILUNATE DISLOCATION (PLD)

CARPAL INSTABILITY COMPLEX-PERILUNATE TYPE (CIC-PLI) see PERILUNATE INSTABILITY (PLI)

CARPAL INSTABILITY DISSOCIATIVE (CID) (FIGURE 13)

SYNONYM: none

CLINICAL: transosseous and/or transarticular dissociation withinthe proximal or distal carpal rows (PCR or DCR)

RADIOLOGIC: when radiologic findings are present, they will dem-onstrate asynchronous movement or alignment between or throughbones within the proximal or distal carpal rows.

COMMENTS: 1) intercarpal communications shown on arthrogra-phy or seen at arthroscopy or at operation may have no appreciablemechanical or kinematic effect. 2) CID is rare in the DCR without as-sociated metacarpal instability, in which case the preferred term is“longitudinal or axial instability” of some type. 3) See comment #6and reference #7 in CARPAL INSTABILITY COMBINED OR COM-PLEX (CIC).


REFERENCE: 1. see CARPAL INSTABILITY COMBINED (CIC)

CARPAL INSTABILITY DISSOCIATIVE—DORSAL INTERCALATEDSEGMENT INSTABILITY (CID-DISI) (FIGURE 14)

SYNONYM: none

CLINICAL: transosseous and/or transarticular dissociation(s) withinthe proximal or distal carpal rows associated with a carpal malalign-ment characterized by pathologic extension of the lunate with respectto the radius and/or flexion of the capitate with respect to the lunate

RADIOLOGIC: in the presence of a recognized DISI, radiographicevidence of dissociation between any two contiguous carpal boneswithin the same carpal row, either the proximal carpal row or the dis-tal carpal row

COMMENTS: 1) CID-DISI is the combination of clinical and radio-logic findings necessary to support both diagnoses of DISI and CID.2) A common CID-DISI is seen with scapholunate dissociation(SLD), but it also is seen with a fractured scaphoid when there isassociated carpal collapse. To date, CID-VISI has been seen almostexclusively in the proximal carpal row (PCR). 3) The specific mala-lignments, dissociations, subluxations, and fractures within the prox-imal or distal carpal row that compose the abnormality should benamed. 4) CID-DISI includes, but is not synonymous with SLD and

Fig. 13b

Fig. 13a

CARPAL INSTABILITY DISSOCIATIVE (CID): a) the PA view demonstrates foreshortening of the scaphoid and tilting of the lunate (triangular-shaped lunate) consistent with palmar tilting of these two bones. Disso-ciation at the lunotriquetral joint is indicated by a break in Arc 1 at the lunotriquetral joint (arrows). Because of palmar tilting of the scaphoid and lunate, the ventral portion of the scapholunate (SL) joint is the prox-imal portion (between large arrowheads) of this joint. The ventral and dorsal portions of the SL joint can normally be wider than its midportion (between small arrowheads). b) On the lateral view, the scaphoid and lunate are both tilted palmarly with a normal scapholunate angle of 40° but with an increased capitolunate angle of 55°. These are findings of VISI with dissociation at the lunotriquetral joint, or CID-VISI. (Reprinted with permission from Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saunders; 1996. p 219. Fig 8-19, A and B.)



scaphoid fracture with DISI collapse deformity of the proximal car-pal row. 5) See comment #6 and reference #7 in CARPAL INSTABIL-ITY COMBINED OR COMPLEX (CIC).


REFERENCE:1. see CARPAL INSTABILITY COMBINED (CIC)

CARPAL INSTABILITY DISSOCIATIVE—VOLAR INTERCALATEDSEGMENT INSTABILITY (CID-VISI) (SEE FIGURE 13)

SYNONYM: none

CLINICAL: transosseous and/or transarticular dissociation(s) withinthe proximal or distal carpal rows associated with a carpal malalign-ment characterized by pathologic flexion of the lunate, usually inassociation with the scaphoid, with respect to the radius and/or ex-tension of the capitate with respect to the lunate

RADIOLOGIC: in the presence of a recognized VISI, radiographicevidence of dissociation between any two contiguous carpal boneswithin the same carpal row, either proximal or distal

COMMENTS: 1) CID-VISI is the combination of clinical and radio-logic findings necessary to support both diagnoses of VISI and CID.2) The most common CID-VISI is seen with lunotriquetral dissocia-tion (LTD). 3) To date, CID-VISI has been seen almost exclusively in

the proximal carpal row (PCR). 4) The specific malalignments, disso-ciations, subluxations, and fractures within the proximal or distalcarpal row that compose the abnormality should be named. 5) Seecomment #6 and reference #7 in CARPAL INSTABILITY COM-BINED OR COMPLEX (CIC).


REFERENCE: 1. see CARPAL INSTABILITY COMBINED (CIC)

CARPAL INSTABILITY NONDISSOCIATIVE (CIND) (FIGURE 15)

SYNONYM: none

CLINICAL: a general class of carpal instability existing either at theradiocarpal or the midcarpal joint levels with intact proximal anddistal carpal rows

RADIOLOGIC: a malposition or abnormal movement of the entireproximal carpal row as a unit (common) or the entire distal carpalrow (exceedingly rare). The site of abnormality can be at the radio-carpal level, midcarpal level, or both, but each row itself is intact. Theabnormal motion may be associated with a “clunk.”

COMMENTS: 1) this is midcarpal instability (dissociation between theproximal and distal carpal rows) or proximal instability (dissociationbetween the distal radius and the first carpal row). 2) Ligamentous de-

Fig. 14a

CARPAL INSTABILITY DISSOCIATIVE—DORSAL INTERCALATED SEGMENT

INSTABILITY (CID-DISI): a) on this PA view, the scapholunate joint space is

widened (between arrows) more than twice the width of the capitolunate

joint. b) The lateral view shows dorsal tilting of the lunate and ventral tilting

of the scaphoid with resultant scapholunate angle of 80° consistent with

DISI configuration. An osseous projection on the dorsal rim of the lunate

(arrowhead) makes the distal articular surface of the lunate project to be

less dorsally tilted than is probably present. Such DISI configuration with

the scapholunate dissociation makes this a CID-DISI. The two white den-

sities ventral to the lunate are artifacts. (Modified and reprinted with

permission from Gilula LA, Yin Y, editors. Imaging of the wrist and hand.

Philadelphia: WB Saunders; 1996. p 218. Fig 8-18, A and B.)

Fig. 14b



fects seen at arthrography, arthroscopy, or surgery between radiocarpaland midcarpal joints without abnormal kinematics do not imply car-pal instability dissociative (CID). 3) The posture of the collapsed rowmay be either extension or flexion. 4) See comment #6 and reference #7in CARPAL INSTABILITY COMBINED OR COMPLEX (CIC).


REFERENCES: 1. see CARPAL INSTABILITY COMBINED (CIC)

2. Ambrose L, Posner MA. Lunate-triquetral and midcarpal joint instability. Hand Clin. 1992;8:653-68.

3. Lichtman DM, Schneider JR, Swafford AR, Mack GR. Ulnar midcarpal insta-bility—clinical and laboratory analysis. J Hand Surg [Am]. 1981;6:515-23.

4. Wright TW, Dobyns JH, Linscheid RL, Macksoud W, Siegert J. Carpal instability non-dissociative. J Hand Surg [Br]. 1994;19:763-73.

CARPAL INSTABILITY NONDISSOCIATIVE—DORSAL INTERCALATED SEGMENT INSTABILITY (CIND-DISI) (SEE FIGURE 15)

SYNONYM: none

CLINICAL: a carpal instability existing either at the radiocarpal orthe midcarpal joint levels with intact proximal and distal carpal rowsassociated with pathologic extension of the lunate (along with thescaphoid and the triquetrum) with respect to the capitate and radius

RADIOLOGIC: in the presence of a recognized DISI, no radiographicevidence of dissociation (static or dynamic) exists between any twocontiguous carpal bones within either carpal row. The CIND aspect ofthe instability must be proven by demonstrating competence at thetwo ligamentous connections of the proximal carpal row, i.e., in thescapholunate interosseous ligament and the lunotriquetral ligament.

COMMENTS: 1) since there is by definition (of CIND) no significantscapholunate or lunotriquetral ligament abnormality, the scapholunateand lunotriquetral angles are normal. 2) CIND-DISI is the combina-tion of clinical and radiologic findings necessary to support both diag-noses of DISI and CIND. The CIND part of the diagnosis may beconfirmed by demonstrating no abnormal motion between adjacentcarpal bones at radiographic examination, arthroscopy, or surgical in-spection. 3) Some experts believe that: (a) this condition must be dueto a combined lesion located at both the midcarpal and radiocarpallevels (references #2 and #3 in CIC); (b) as a rule, ligament tears arepresent at both midcarpal and radiocarpal levels; (c) it is mechanicallyimpossible to have malposition of the proximal carpal row withoutcombined pathology; and (d) these comments are supported by thefact that cutting a specific ligament does not change the position of thecarpal bones, even if pathologic movement can be observed kinemati-

Fig. 15b

CARPAL INSTABILITY NONDISSOCIATIVE (CIND): a) PA view: the

scaphoid is elongated from dorsal tilting of the scaphoid, with

marked osteoarthritis involving the scaphotrapezial, scaphotrapezoi-

dal, and the first carpometacarpal joints. Degenerative ossicles are

present radial to the trapezium and between the first and second

metacarpal bases. The trapezium has lost some of its volume, and

the first metacarpal is subluxed radially. Arcs 1 and 2 are intact,

indicative that the entire proximal carpal row is moving as a unit

without dissociation at the lunotriquetral or scapholunate joints. b)

The lateral view shows dorsal tilting of the scaphoid and lunate

maintaining a scapholunate angle of about 65°, while the capitolu-

nate angle is increased to about 40°. These features are that of a

DISI configuration with the entire proximal carpal row moving as a

unit or DISI-CIND.

Fig. 15a



cally (references #2 and #3 in CIC). 4) See comment #6 and reference#7 in CARPAL INSTABILITY COMBINED OR COMPLEX (CIC).



2. Sennwald GR, Zdravkovic V. Wrist arthroscopy: a prospective analysis of 53 post-traumatic carpal injuries. Scand J Plast Reconstr Surg Hand Surg. 1997;31:261-6.

3. North ER, Meyer S. Wrist injuries: correlation of clinical and arthroscopic find-ings. J Hand Surg [Am]. 1990;15:915-20.

CARPAL INSTABILITY NONDISSOCIATIVE—VOLAR INTERCALATED SEGMENT INSTABILITY (CIND-VISI) (FIGURE 16)

SYNONYM: none

CLINICAL: a carpal instability existing either at the radiocarpal orthe midcarpal joint levels with intact proximal and distal carpal rows

associated with pathologic flexion of the lunate with respect to thecapitate and radius

RADIOLOGIC: in the presence of a recognized VISI, no radiographicevidence of dissociation (static or dynamic) exists between any twocontiguous carpal bones within either carpal row. The CIND aspectof the instability must be proven by demonstrating competence at thetwo ligamentous connections of the proximal carpal row, i.e., in thescapholunate interosseous ligament and the lunotriquetral ligament.

COMMENTS: 1) since there is by definition (of CIND) no signifi-cant scapholunate or lunotriquetral ligament abnormality, thescapholunate and lunotriquetral angles are normal. 2) CIND-VISI isthe combination of clinical and radiologic findings necessary to sup-port both diagnoses of VISI and CIND. The CIND part of the diag-nosis may be confirmed by demonstrating no abnormal motionbetween adjacent carpal bones at radiographic examination, arthros-copy, or surgical inspection. 3) Some experts believe that: (a) thiscondition must be due to a combined lesion located at both the mid-carpal and radiocarpal levels (references #2 and #3 in CIC); (b) as arule, ligament tears are present at both midcarpal and radiocarpallevels; (c) it is mechanically impossible to have malposition of theproximal carpal row without combined pathology; and (d) thesecomments are supported by the fact that cutting a specific ligamentdoes not change the position of the carpal bones, even if pathologicmovement can be observed kinematically (references #2 and #3 inCIC). 4) See comment #6 and reference #7 in CARPAL INSTABIL-ITY COMBINED OR COMPLEX (CIC).


REFERENCES:1. see CARPAL INSTABILITY COMBINED (CIC)

2. Sennwald GR, Zdravkovic V. Wrist arthroscopy: a prospective analysis of 53 post-traumatic carpal injuries. Scand J Plast Reconstr Surg Hand Surg. 1997;31:261-6.

3. North ER, Meyer S. Wrist injuries: correlation of clinical and arthroscopic find-ings. J Hand Surg [Am]. 1990;15:915-20.

Fig. 16a

CARPAL INSTABILITY NON-DISSOCIATIVE—VOLAR INTERCALATED SEG-

MENT INSTABILITY (CIND-VISI): a) PA view: slight foreshortening of the

scaphoid and triangular shape (tilting) of the lunate is present. These

changes of the scaphoid and lunate are actually more prominent than

shown here, since the wrist is in some dorsiflexion as evidenced by

the fact that the second and third CMC joints are not in profile, and

the hook of the hamate is elongated. No radial deviation is present

since the third metacarpal shaft is grossly coaxial with the axis of the

radius. Parallel articular surfaces between the lunate and triquetrum

and suggestion of similar parallelism between the scaphoid and

lunate on the PA view combined with presence of intact carpal arcs I

and II on the PA view support the fact that the entire proximal carpal

row has moved as a unit. b) Lateral view: both the scaphoid and

lunate are tilted palmarly with a normal scapholunate angle of about

50°. The capitolunate angle is abnormally increased to about 45°.

This configuration of CIND-VISI may commonly be a normal variant

and should be compared to the opposite side to see if the opposite

side has the same configuration without symptoms. An extra ossicle

projects dorsal to the lunate and proximal to the triquetrum (arrow).

Fig. 16b



CARPAL PILLARS PROJECTION see CARPAL TUNNEL VIEW

CARPAL REVOLUTE see SLIDER-CRANK MECHANISM

CARPAL TUNNEL VIEW (FIGURE 17)

SYNONYMS: carpal tunnel projection, carpal pillars projection

CLINICAL: NA

RADIOLOGIC: a radiographic view showing the arch of the carpaltunnel. Two common methods can be used for its exposure: 1) hav-ing the patient hold his or her fingers and wrist in the maximum ex-tended position, the central x-ray beam is passed from distal toproximal across the hand and wrist at 10-15° centered at and parallelto the third metacarpal shaft with the wrist held over or lying on theradiographic screen; and 2) having the patient place the palm of hisor her hand flat on a radiographic screen, the wrist is hyperextendedas much as possible and the central beam of the x-ray is centered atthe midportion of the carpal tunnel and projected from proximal todistal at 40° to the radiographic cassette.

COMMENT: variation in positioning affects which portion (proxi-mal, distal, radial, or ulnar aspects) of the carpal tunnel area will beshown.


REFERENCES: 1. Hart VL, Gaynor V. Roentgenographic study of the carpal canal. J Bone Joint

Surg. 1941;23:382-5.

2. Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saun-ders; 1996. p 148-50.

CARPE BOSSU see CARPAL BOSS

CARPOMETACARPAL (CMC) DISLOCATION (FIGURE 18)

SYNONYM: hand-wrist dislocation

CLINICAL: a general term reserved for complete loss of articularcongruence without fractures at one or more individual carpometa-carpal joint(s)

RADIOLOGIC: suspect with loss of normal parallelism between ad-jacent articular cortices of one or more metacarpal bases and adja-cent carpal bones most easily seen on the neutral supine (AP) orprone (PA) views of the wrist and confirmed for complete displace-ment on additional views

COMMENTS: 1) this is one of the CMC instability categories; theother two are CMC subluxation and CMC fracture-dislocation/sub-

Fig. 17b

Fig. 17a

CARPAL TUNNEL VIEW: a) a small sponge is placed under the wrist.

The wrist is extended as much as possible by the patient’s other

hand, and the central beam (indicated by the pointer) is aimed to

pass through the palmar aspect of the carpal tunnel, angled 25-30° to

the third metacarpal shaft. b) Another way to obtain this view is to

place the hand flat on the cassette or tabletop and extend the wrist

as much as possible. The central beam (indicated by the pointer) is

directed tangent to the palmar aspect of the wrist parallel to the long

axis of the carpal tunnel. c) The carpal tunnel view is depicted here

with P = pisiform, H = hook of hamate, S = scaphoid (arrow points to

scaphoid), Td = trapezoid, and Tm = trapezium. (Modified and

reprinted with permission from Gilula LA, Yin Y, editors. Imaging of the

wrist and hand. Philadelphia: WB Saunders; 1996. p 148-9. Figs 5-

52, A and B; and 5-53A.)

Fig. 17c



luxation. 2) Pure CMC dislocation without fracture is extremely rareof the second through fifth CMCs.

CODE: Clinical Conditions: Fractures-Dislocations-Diastases (IIIA)

REFERENCE:1. Lawlis JF 3rd, Gunther SF. Carpometacarpal dislocations. Long-term follow-up.

J Bone Joint Surg Am. 1991;73:52-9.

CARPOMETACARPAL (CMC) FRACTURE-DISLOCATION (FIGURE 19)

SYNONYM: hand-wrist fracture dislocation

CLINICAL: a general term reserved for any carpometacarpal disloca-tion that is accompanied by a fracture of one or more of the opposingarticular surfaces (see CARPOMETACARPAL DISLOCATION)

RADIOLOGIC: loss of any congruence (loss of normal parallelismbetween adjacent cortices) between the two articular componentsof any CMC joint associated with a fracture of some portion of thatjoint

COMMENTS: 1) all finger CMCs may be involved together or somemay be involved with fractures, subluxations, or dislocations of theadjacent carpal bones. 2) The dislocations are more often dorsal, butcan be volar, radial, or ulnar. 3) When combined with adjacent carpalinstabilities, this condition will fall into the longitudinal (axial) insta-bility group.


REFERENCES: 1. see CARPOMETACARPAL (CMC) DISLOCATION

2. Garcia-Elias M, Bishop AT, Dobyns JH, Cooney WP, Linscheid RL. Transcarpal carpometacarpal dislocations, excluding the thumb. J Hand Surg [Am]. 1990;15:531-40.

3. Cain JE Jr, Shepler TR, Wilson MR. Hamatometacarpal fracture-dislocation: classification and treatment. J Hand Surg [Am]. 1987;12:762-7.

4. Dobyns JH. Fractures and dislocations at the base of the metacarpals. In: Bar-ton NJ, editor. Fractures of the hand and wrist. Edinburgh: Churchill Living-stone; 1988. p 125-33.

CARPOMETACARPAL INSTABILITY

SYNONYM: none

CLINICAL: an abnormal condition occurring between the metacar-pal(s) and the distal carpal row, which results in the inability to main-tain normal anatomic relationship(s) under physiologic loads

RADIOLOGIC: a radiographic diagnosis of carpometacarpal insta-bility is suspected if there is any evidence of subluxation of a car-pometacarpal joint as seen either on a static or dynamic (i.e., stress)radiograph (see comment #1).

COMMENTS: 1) some authorities believe that a fixed instability is acontradiction in terminology, i.e., that such a condition is no longerdeserving of being called unstable. However, the definition of “insta-bility” includes any situation where anatomic alignment cannot bemaintained. In such a situation, the abnormal alignment, although itFig. 18

CARPOMETACARPAL (CMC) DISLOCATION: on this PA slightly

obliqued view of the wrist, the thumb metacarpal is profiled in a lat-

eral position. Radial dislocation of the base of the first metacarpal

is evidenced by complete lack of articulation between the first

metacarpal and the trapezium and some overlapping of the well-

profiled base of the first metacarpal and the adjacent trapezium.

Fig. 19a

CARPOMETACARPAL (CMC) FRACTURE-DISLOCATION: a) on this

PA view, the bases of the second through fifth metacarpals are

overlapping their adjacent carpal bones, indicative of CMC dislo-

cations at the second through fifth CMC joints. A bone density

(arrow) has some parallelism (between arrowheads) to the capi-

tate, suggesting a fracture fragment of the base of the third

metacarpal that has remained articulating with the capitate. A

density ulnar to the hamate (curved arrow) and adjacent to the

fifth metacarpal base is a chip fracture off the ulnar edge of the

hamate. b) The lateral view confirms dislocation of the second

through fifth metacarpals at their CMC joints and shows that the

dislocation is dorsal and proximal. A fragment of bone distal to

the capitate (arrow) represents the piece of the third metacarpal

base as seen on the PA view (Fig 19A). The final diagnosis of this

abnormality is trans-third metacarpal, transhamate, dorsal sec-

ond through fifth carpometacarpal fracture-dislocation.



may be fixed (or stable in the abnormal state), progressed from nor-mal to abnormal alignment and may further deteriorate. 2) SinceCMC dislocations and fracture-dislocations may also be unstable(old, healed ones may be stable), this term may be used as a majorcategory with three subcategories, i.e., CMC subluxation, CMC dis-location, and CMC fracture-dislocation.


REFERENCE:1. see CARPOMETACARPAL (CMC) DISLOCATION and FRACTURE-DISLOCATION

CARPOMETACARPAL SUBLUXATION (FIGURE 20)

SYNONYM: none

CLINICAL: any degree of displacement in any direction short of com-plete loss of contact between the distal articular surface of the distalcarpal bone(s) and its (their) respective metacarpal articulation(s)

RADIOLOGIC: subluxation of the carpometacarpal joint exists whenthere is anything less than 100% contact between opposing articularsurfaces.

COMMENTS: 1) the direction of subluxation is defined by the direc-tion of displacement of the distal segment. 2) The amount of sublux-ation can be given as a percentage determined by the measureddisplacement divided by the normal articular dimension in that sameplane. 3) A CMC subluxation may or may not be unstable, thereforecarpometacarpal subluxation and carpometacarpal instability are notsynonymous. This is considered by some experts to be a subcategoryof CMC instability (see COMMENTS under CMC INSTABILITY).


REFERENCE:1. see CARPOMETACARPAL (CMC) DISLOCATION and FRACTURE-DISLOCATION

CATCH-UP CLUNK

SYNONYMS: catch-up phenomenon, homing-in phenomenon

CLINICAL: a carpal malalignment present with motion or other pro-vocative maneuver during which the usual pattern of carpal motion isnot maintained. Near the end of the maneuver, the bone(s), which arenot following the usual motion pattern, suddenly move toward thenormal position, often producing a palpable, perceptible (to the pa-tient) and audible, sudden alteration of position. Although similar“clunks” can occur with the sudden repositioning of one bone (e.g.,

Fig. 19b

Fig. 20a

CARPOMETACARPAL (CMC) SUBLUXATION: a) PA view: some exten-

sion of the wrist is evident by loss of clear profile of the second and

third carpometacarpal joints and elongation of the hook of the

hamate. Good parallelism is present at the fifth and the ulnar

aspect of the third CMC joint. The intervening fourth CMC joint has

lost profile of its parallel articular cortices. More specifically, the

cortex of the base of the fourth metacarpal is not visible, whereas

the adjacent cortex of the hamate (arrowheads) is clearly visible. A

defect involves the radial cortex of the base of the fourth metacar-

pal (arrow). These findings support some type of fracture sublux-

ation/dislocation at the fourth CMC joint. The fifth metacarpal

shaft is fractured at its distal fourth. b) The lateral view shows the

base of one metacarpal (arrow) projecting dorsal to the carpus,

supporting dorsal subluxation of a metacarpal. c) A sagittal CT sec-

tion through the junction of the fourth and fifth CMC joints shows

dorsal subluxation of the fourth metacarpal at its base. The arrow

on the reader’s right points to the dorsal cortex of the fourth meta-

carpal. The arrow to the reader’s left indicates part of the fifth

metacarpal base, which is articulating proximally (toward the bot-

tom of the figure) to the hamate. This example shows subluxation,

but it actually is a case of a fracture subluxation of the fourth CMC

joint since there is also a fracture of the fourth metacarpal base.

(Fig 20C is modified and reprinted with permission from Gilula LA,

Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB

Saunders; 1996. p 433. Fig 16-21.)



the subluxed scaphoid), the classic “catch-up-clunk” describes the sud-den positioning of the entire proximal carpal row, which commonlyoccurs during movement from one deviation position to another(usually from radial deviation to ulnar deviation) although gripping

and circumduction along with the deviation are sometimes more pro-vocative. This may occur with midcarpal instability. (See COMMENTS.)

RADIOLOGIC: a common type of this “clunk” can be recognized bydisplacing the carpus palmarly while the wrist is in radial deviation.Maintaining this palmar-displacing stress while moving the wristinto ulnar deviation, the proximal carpal row as identified by thescaphoid and lunate will remain palmarly tilted until near the end ofulnar deviation. At this point, the proximal carpal row abruptly tiltsdorsally, sometimes with an audible noise, but often with a palpablejerk (see comment #6). Videotape examination (or cineradiography)can demonstrate this “jumping” or jerky motion best in the lateralposition, but also in the PA position.

COMMENTS: 1) many authorities do not like this term and feel thatthis term should be discarded, as it is used differently by differentpeople. 2) This term can be used to describe any bone that movesback into anatomic relationship with an audible or palpable noise in-cluding also the scaphoid test with rotary subluxation of thescaphoid. 3) Sometimes the lunate lags behind the scaphoid on radialtranslation, then suddenly extends and catches up to the scaphoid.This motion is associated with an audible and palpable clunk. 4) It iscommon that the maneuver described above under RADIOLOGICoccurs in lax-jointed individuals and it may occur bilaterally sym-metrically or asymmetrically, but typically presents with pain only inone wrist. 5) Some experts believe that this audible sound occurs be-cause of lack of stability due to failure of damaged ligament(s) tomaintain normal carpal relationships during motion. 6) To producethis clunk, loading of the wrist is usually necessary. This can be doneas the pronated wrist is moved from radial to ulnar deviation withcompression applied (forcing the wrist toward the elbow).

CODE: Tests (IV)

REFERENCES:1. Dobyns JH, Linscheid RL, Chao EYS, Weber ER, Swanson GE. Traumatic insta-

bility of the wrist. AAOS Inst Course Lect. 1975;24:182-99.

2. Lichtman DM, Schneider JR, Swafford AR, Mack GR. Ulnar midcarpal insta-bility—clinical and laboratory analysis. J Hand Surg [Am]. 1981;6:515-23.

3. Schernberg F. [Mediocarpal instability]. Ann Chir Main. 1984;3:344-8. French.

CENTRAL COLUMN (FIGURE 21)

SYNONYM: none

CLINICAL: the capitate and lunate and their proximal and distal ar-ticulations

RADIOLOGIC: from proximal to distal, this is composed of the radi-olunate joint, lunate, capitolunate (lunocapitate) joint, capitate, andcapitate third metacarpal joint.

COMMENTS: 1) “column” here is used in the anatomic sense, assome authorities do not believe in the functional columnar theory ofthe wrist. 2) Others believe that this “central column” is importantfor transmission of loads from the hand to the forearm. 3) Some ex-perts believe that this term is of only historical interest. The capitatefunctionally shifts from the scaphoid and lunate, and a rupture of thescapholunate ligament permits the capitate head to protrude betweenthese two bones.

CODE: Anatomic: Central (IIB)

REFERENCES:1. Navarro A. La fisiologia del carpo. An Inst Clin Quirurg Chirurgia Exp. 1937;

6:199-232.

2. Taleisnik J. The wrist. New York: Churchill Livingstone; 1985.

Fig. 20b

Fig. 20c



CEPHALAD see PROXIMAL

CHAMAY MEASUREMENT FOR ULNAR TRANSLATION (FIGURE 22) see ULNAR TRANSLATION

CLUNK

SYNONYM: thud

CLINICAL: a low-pitched dull sound (as opposed to the sharp, ring-ing sound of “clank” or “clink”) and palpable phenomenon producedby a sudden and significant shift in alignment of articular surfaces

RADIOLOGIC: NA

COMMENTS: 1) this is not restricted to one observable phenome-non, but it is usually best seen during videotape or cineradiographicexamination of the moving wrist and is usually marked by a suddenshift of the entire proximal carpal row or a part of the proximal carpalrow from a dorsiflexed to a palmar-flexed position or vice versa (seeCATCH-UP CLUNK). 2) Some authorities prefer not to definesounds and feelings.

CODE: General Terms (V)

REFERENCE:1. see MIDCARPAL INSTABILITY

COLLAPSE DEFORMITY (SEE FIGURES 12B, 13B, 14B, 15B, 16B) see CONCERTINA DEFORMITY

SYNONYMS: carpal collapse, zigzag deformity/collapse, concertinadeformity/collapse

CLINICAL: loss of carpal stability with independent proximal anddistal row motion

RADIOLOGIC: 1) any abnormal angular relationship between thelong axis of the capitate and the mid dorsal-palmar lunate axis asseen on the neutral lateral. 2) Any carpal malalignment in which

there is a decrease in the carpal height index (see carpal height) with-out evidence of destruction of carpal bones.

COMMENTS: 1) this is often recognized by a lunate tilted abnor-mally in the dorsal or palmar direction with the wrist in a neutral po-sition. 2) Some experts believe that the zigzag and the concertinacollapse deformities are not true synonyms, but are special cases ofcollapse deformity. 3) The term “collapse deformity” is used herewith respect to the wrist but could apply to other parts of the body.

CODE: Clinical Conditions: Residuals of Injuries (IIIC)

REFERENCES: 1. Gilford WW, Bolton RH, Lambrinudi C. The mechanism of the wrist joint with

special reference to fractures of scaphoid. Guy’s Hosp Rep. 1943;92:52-9.

2. Fisk GR. Carpal instability and the fractured scaphoid. Ann R Coll Surg Engl. 1970;46:63-76.

3. Linscheid RL, Dobyns JH, Beabout JW, Bryan RS. Traumatic instability of the wrist. Diagnosis, classification, and pathomechanics. J Bone Joint Surg Am. 1972;54:1612-32.

4. Sebald JR, Dobyns JH, Linscheid RL. The natural history of collapse deformi-ties of the wrist. Clin Orthop. 1974;104:140-8.

COLUMNAR AXIS see LONGITUDINAL AXIS

Fig. 22

CHAMAY MEASUREMENT FOR ULNAR TRANSLATION: ulnar translation is

evaluated by determining L4/L1 when L1 is the length of the third meta-

carpal, L4 is the capitate-radial styloid distance, and L2 is the carpal

height line passing through the center of the capitate head (C). L4/L1 =

0.28 + 0.03; ARS = axis of the radial styloid. (Reprinted with permission

from Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia:

WB Saunders; 1996, p 208, Fig 8-6C.)

Fig. 21

COLUMNAR CARPUS: this diagram demonstrates the columnar concept of the carpus with the central (C) column being the flexion-extension column composed of the lunate with the distal carpal row. The lateral column (L) is the mobile column and consists of the scaphoid. The medial or rotation col-umn (M) is composed of the triquetrum. (Reprinted with permission from Taleisnik J. The wrist. New York: Churchill Livingstone; 1985. p 41. Fig 3-2.)



COMBINATION ARC INJURY see GREATER ARC INJURY; LESSER ARC INJURY

COMPETENT (AS RELATES TO LIGAMENTS)

SYNONYMS: physiologic integrity, intact, functionally adequate/suf-ficient, physiologically intact

CLINICAL: 1) a competent ligament is one that prevents abnormaldisplacement, angulation, or rotation between adjacent bones. 2) Astructure, not necessarily a ligament although most often used in thatcontext among wrist investigators, which may be normal or injuredbut is adequate for unrestricted functional use.

RADIOLOGIC: lack of evidence for incompetence, i.e., no evidencefor dislocation, subluxation, or loss of congruence

COMMENTS: 1) some authorities prefer dropping this term. In Eu-rope, “competent” has more to do with “entitled” or “skillful” thanwith “anatomically intact.” 2) The word is used in one of its stan-dard meanings, i.e., adequate for a purpose, and would not requirelisting except that it is not familiar in this context to some investiga-tors. 3) Competency must be shown both on a static examinationand dynamically. 4) Maybe this is not the best word, but a term isneeded to describe anatomic structures that are not adequate forwhatever reason (injury, congenital, disease, infection, etc.) tomaintain normal stability of a musculoskeletal part during functionand even at rest. Structures that are inadequate for these purposesare incompetent.


REFERENCES: 1. Dobyns JH, Berger RA. Dislocations of the carpus. In: Chapman MW, Madison

M, editors. Operative orthopedics. 2nd ed, vol 2. Philadelphia: JB Lippincott; 1993. p 1289-305.

2. The New Lexicon Webster’s Dictionary of the English Language. 1989 edition. p 200.

CONCERTINA COLLAPSE see CONCERTINA DEFORMITY and COL-LAPSE DEFORMITY

CONCERTINA DEFORMITY (SEE FIGURES 12B, 13B, 14B, 15B, 16B) see COLLAPSE DEFORMITY

SYNONYMS: zigzag deformity/collapse, carpal collapse

CLINICAL: 1) a zigzag collapse deformity of the capitate-lunate-radius axis as seen on the lateral radiograph in association with dis-ruption of the structural support (ligamentous or osseous) of thecarpus. 2) A zigzag collapse deformity of the capitate-lunate-radiusaxis, either VISI or DISI in configuration, more notable in lateralthan in PA projection, associated with diminished carpal height in-dex (CHI) and due to damage to ligament, bone, or both.

RADIOLOGIC: pathologic malalignment, particularly on the lateralprojection, as described in VISI and DISI. Suggestive abnormalitiesare also evident on PA radiographs as for the current usage of VISIand DISI.

COMMENTS: 1) see CARPAL COLLAPSE. 2) This is mainly of his-torical interest. 3) Fisk defined “concertina” STRICTLY as it appliedto fractures of the scaphoid.

CODE: Clinical Conditions: Residuals of Injury (IIIC)

REFERENCE:

1. see COLLAPSE DEFORMITY

CONSTRAINT see TETHER

CORONAL PLANE/POSITION (FIGURE 23) see ANTEROPOSTERIOR VIEW OR PROJECTION

SYNONYMS: frontal plane/position, radial to ulnar or ulnar to radialplane, PA or AP view of wrist on radiographs

CLINICAL: any plane passing longitudinally through the wrist fromside to side equivalent to the radioulnar plane, at right angles to themedian plane. The coronal plane is obtained when the arm is along-side the body with the palm facing anteriorly or posteriorly withoutwrist flexion or extension and divides the body into front and back(dorsal and ventral [volar or palmar]) parts. This plane is so calledbecause such a plane roughly parallels the frontal (coronal) suture ofthe skull.

RADIOLOGIC: see CLINICAL. The radiographic views that repre-sent the coronal plane are the AP or PA views or “cuts” (“cuts” refersto sections obtained at different levels with tomography, either con-ventional or computed in type).

COMMENTS: 1) with the hand or wrist in the true coronal position,

Fig. 23

CORONAL PLANE: an anatomic section through the wrist in a

plane that passes from radial to ulnar. This resulting section

provides a view that looks like a PA or AP view of the wrist on

radiography. (Case donated by Dr. Rudi Richli, Radiologist, MD

Anderson Hospital, Houston, Texas.)



with the palm facing forward, an AP radiograph results. With thehand in a similar position, but rotated 180° from the anatomic posi-tion so the palm faces the back side of the patient, a PA radiographresults. Current standard procedure for obtaining either one of theviews requires that the forearm-wrist-hand unit be in the “0′” or“midposition” when either PA or AP radiographs are to be made. 2)In radiology, this plane corresponds to the AP or PA views; however,strictly speaking, a frontal view would only be the AP or “frontal”view of the hand or wrist. 3) When the palm is facing forward in thisplane (supinated), the hand is considered to be in the anatomic posi-tion. 4) Practically speaking, however, many x-rays are still madewith the forearm-wrist-hand unit in either full supination or full pro-nation, and it is wise for the image interpreter to check some guide-line, such as the position of the ulnar styloid, to confirm whether theprone or supine position was used. 5) The resultant parts after acoronal section has been passed may be equal (true coronal or fron-tal) or unequal (paracoronal or parafrontal). 6) Particularly in Euro-pean articles, the AP and PA views may be referred to in terms ofanatomic planes.

CODE: Radiologic: Planes (IB)

REFERENCE:

1. anatomy or radiology textbooks

DE QUERVAIN’S FRACTURE-DISLOCATION see comment #5 under PERILUNATE FRACTURE-DISLOCATION

DESTABILIZATION see INSTABILITY

DIASTASIS (FIGURE 24; SEE ALSO FIGURES 12A, 14A)

SYNONYMS: gap, distraction (fracture-diastasis)

CLINICAL: abnormal separation of two anatomic structures butused only with reference to osseous gaps in the present context

RADIOLOGIC: 1) there is a measurable increase of the normal dis-tance between two bones (e.g., scapholunate diastasis). 2) Fracture-diastasis, e.g., distraction consequent to excessive traction of fracturefragments, may also be seen with increased gap between opposingparts of the fracture.

COMMENTS: 1) although used in reference to pathology, an appar-ent diastasis may be a normal variant, as when appropriate amountsof bone are present but are not yet ossified (as incomplete ossificationof the immature scaphoid) or may be associated with normal laxityof supporting structures. 2) Diastasis is not always synonymous withdissociation, as dissociation can be present in the absence of jointgapping (see DISSOCIATION).


REFERENCE:1. Linscheid RL, Dobyns JH, Beabout JW, Bryan RS. Traumatic instability of the

wrist. Diagnosis, classification, and pathomechanics. J Bone Joint Surg Am. 1972;54:1612-32.

DISLOCATION (SEE FIGURE 18)

SYNONYM: luxation

CLINICAL: complete loss of articular surface contact of a given joint

RADIOLOGIC: same as CLINICAL

COMMENTS: NA


REFERENCE:1. standard dictionary; radiology, traumatology, and orthopedic textbooks

DISLOCATION OF... see part dislocated, e.g., DISTAL RADIOULNAR DISLOCATION

DISPLACEMENT

SYNONYM: none

CLINICAL: a shift from anatomic position during rest, motion, orforce application, which may be angular, axial, rotational, or transla-tional displacement. This may be normal or abnormal, i.e., physio-logic or pathologic.

RADIOLOGIC: loss of anatomic relations with abnormal movementbetween two or more adjacent parts

COMMENTS: none


REFERENCE:1. standard dictionary

DISSOCIATION (SEE FIGURES 12A, 13A, 14A, 24)

SYNONYMS: un- or not linked, un- or not bonded

CLINICAL: a carpal malalignment in which there is a loss of the nor-mal association of the skeletal elements within either the proximalcarpal row (PCR) or the distal carpal row (DCR) or both

Fig. 24

DIASTASIS: on this PA view, the scapholunate space is widened (dia-

static) more than twice the width of the capitolunate space. Radio-

scaphoid joint space narrowing is present with subcortical sclerosis of

the radius and scaphoid. Spurs (osteophytes) involve the radial styloid

and radial aspect of the scaphoid waist, indicative of osteoarthritis. As

the CMC joints are not in profile and the hamate hook is elongated, this

wrist is extended (the palm is not flat on the cassette). An osseous

mass off the radial aspect of the lunate is consistent with either an

avulsion deformity or a developing osteophyte. The radiolunate joint is

preserved. The features of scapholunate widening, radioscaphoid

osteoarthritis, and preserved radiolunate joint width are diagnostic of

SLAC wrist, before capitolunate osteoarthritis has developed.



RADIOLOGIC: 1) the term “dissociation” may be applied to a mala-lignment pattern in which there is a demonstrated loss of integrity ofone or more intercarpal ligaments within either the PCR or the DCRor both as evidenced by abnormal widening of an interosseous dis-tance or abnormal displacement or offset of one of the three carpalarcs (see CARPAL ARCS). 2) This term may also be applied to similarloss of functional integrity from fracture destabilization.

COMMENTS: 1) usually an arthrogram will demonstrate abnormalflow of contrast between carpal bones, or arthroscopy will show a lig-ament defect at the dissociated site; however, failure to demonstrateor see such a defect may still occur with “dissociated” carpal bones orthrough a fracture site if scar tissue or ligament elongation has devel-oped at the site of dissociation. Importantly, the presence of a perfo-ration through a ligament or triangular fibrocartilage does notnecessarily mean that there is functional dissociation at that site, asasymptomatic perforations commonly occur in the wrist. 2) This iscontrasted to a nondissociated malalignment (CIND), in which theintercarpal (intrinsic) ligaments are intact but the extracapsular (ex-trinsic) ligaments are stretched or disrupted. 3) The dissociation mayoccur because of injury or secondary changes in ligaments (intrinsic,extrinsic, or both) or in bone (fractures; ligament tears or insertionavulsions; infectious, rheumatoid, or crystalline arthropathies; is-chemic, cyst, or tumor deformities; etc.). 4) Pathologic dissociationcan be found at open surgery or arthroscopy in the absence of abnor-mal radiographic or arthrographic findings. 5) Originally, this termwas used for loss of ligament functional integrity. It is now com-monly used for loss of intra-row integrity, whether due to ligamentproblems, bone problems, or both. It still retains the original distinc-tion of referring to intra-row loss of functional integrity (CID),whereas the term “nondissociative” still refers to inter-row problems(CIND). Using this slightly altered concept, it is now appropriate tocall an unstable scaphoid fracture with DISI deformity a “dissociativedeformity,” since there is a dissociative separation and deformity be-tween two components of the proximal carpal row, i.e., the two frag-ments of the scaphoid (see CIND and CID).


REFERENCE:1. Linscheid RL, Dobyns JH, Beabout JW, Bryan RS. Traumatic instability of the


DISTAL CARPAL ROW (DCR) (SEE FIGURE 8A)

SYNONYM: os distale

CLINICAL: the trapezium, trapezoid, capitate, and hamate and theligaments binding them together form the distal carpal row.


COMMENTS: none

CODE: Anatomic: Carpal (IID)

REFERENCES:1. see DIASTASIS

2. anatomy textbooks

DISTAL RADIAL INSTABILITY see DISTAL RADIOULNAR INSTABILITY

DISTAL RADIOULNAR DISLOCATION (FIGURE 25)

SYNONYM: dislocation of the distal radioulnar joint

CLINICAL: a complete loss of joint congruity between the distal end

of the ulna and the sigmoid notch of the radius


COMMENTS: this is actually a dislocation of the distal radius andhand around the distal ulna, since the ulna is the bone that is fixed inplace (fixed at the elbow).


REFERENCE:1. see DISTAL RADIOULNAR INSTABILITY

DISTAL RADIOULNAR FRACTURE-DISLOCATION (FIGURE 26)

SYNONYM: fracture-dislocation of the distal radioulnar joint

CLINICAL: a complete loss of joint congruity between the distalend of the ulna and the corresponding aspect of the radius (at the

Fig. 25b

Fig. 25a

DISTAL RADIOULNAR DISLOCATION: a) on a transaxial computed tomo-

graphic (CT) section through the distal radioulnar joint (DRUJ) with the

wrist in supination, the ulna (U) is dislocated ventrally out of the sig-

moid fossa (arrows) of the distal radius. (Ventral is to the top of the fig-

ure.) b) On another transaxial CT image of the DRUJ with the wrist in

pronation (ventral is to the bottom of the figure), the ulna (U) is nor-

mally positioned in the sigmoid fossa of the distal radius.



sigmoid notch) as a result of fracture of the distal radius or distal ulnaor both


COMMENTS: this would not include Madelung’s and other epiphy-seal dysplasias; however, a fracture deformity of childhood with earlyclosure of the ulnar side of the distal radius epiphyseal plate simulat-ing Madelung’s could be included.



DISTAL RADIOULNAR IMPACTION see IMPINGEMENT, RADIOULNAR (DISTAL)

DISTAL RADIOULNAR INSTABILITY (SEE FIGURES 25, 26, 27)

SYNONYMS: distal ulnar instability, distal radial instability

CLINICAL: an abnormal condition between the distal radius andulna that results in loss of the normal distal radioulnar joint (DRUJ)relationship(s)

RADIOLOGIC: NA

COMMENTS: 1) the status of joint congruency (subluxation or dis-location) can be radiologically assessed, especially with computed to-mography or magnetic resonance imaging; however, instability is aclinical inference. 2) There is often a palpable subluxation, usuallydorsal and rarely volar. With this, there may also be a concomitantsupination of the carpus. This results in the loss of normal jointrelationships under some conditions (i.e., resisted rotation, mani-pulation by the examiner). 3) Instability may be a subjective determi-nation by the patient of his/her ability to function. 4) This is a genericterm covering three subcategories, i.e., DRUJ subluxation, DRUJ dis-location, and DRUJ fracture-dislocation.


REFERENCES: 1. Dobyns JH, Linscheid RL. Fractures and dislocations of the wrist. In: Rock-

wood CA Jr, Green DP, editors. Fractures. Vol 1. Philadelphia: JB Lippincott; 1975. p 345-440.

2. Bowers WH. The distal radioulnar joint. In: Green DP, editor. Operative hand surgery. 2nd ed, vol 2. New York: Churchill Livingstone; 1988. p 939-90.

3. Mino DE, Palmer AK, Levinsohn EM. The role of radiography and computerized tomography in the diagnosis of subluxation and dislocation of the distal radio-ulnar joint. J Hand Surg [Am]. 1983;8:23-31.

DISTAL RADIOULNAR SUBLUXATION (FIGURE 27)

SYNONYM: none

CLINICAL: incomplete loss of normal articular contact between thedistal radius and ulna at the distal radioulnar joint (see comment #2)

RADIOLOGIC: best defined by comparing symptomatic to asymp-tomatic wrists imaged by transaxial views of the distal radioulnarjoint on CT scan or MRI in at least two positions of forearm rotation(full pronation and full supination). Midrotation and supplementalpositions that recreate a patient symptom complex may be necessaryto demonstrate loss of distal radioulnar joint congruence not evidenton the two standard positions (see comment #3).

COMMENTS: 1) this common clinical entity is often asymptomatic.2) As mentioned elsewhere, a subluxation or malalignment may ormay not be unstable. Therefore, this subluxation is not necessarily an“instability.” 3) Analysis of congruency of the distal radioulnar jointdepends on exact symmetric pronation/supination positioning of thewrist during cross-sectional imaging.

Fig. 26a

DISTAL RADIOULNAR FRACTURE-DISLOCATION: a) this PA view dem-

onstrates a fracture of the base of the ulnar styloid with the rest of

the ulna displaced radially, overlapping the radius. b) On the lateral

view, which shows an acceptable SPC relationship (see NEUTRAL LAT-

ERAL VIEW), the ulnar shaft is displaced ventrally. This case shows

transulnar styloid, ventral radial fracture-dislocation of the ulna.

Fig. 26b





DISTAL ULNAR INSTABILITY see DISTALRADIOULNAR INSTABILITY

DORSAL see POSTERIOR

DORSAL BOSS see CARPAL BOSS

DORSAL CARPAL IMPINGEMENT SYNDROME seeDORSAL CARPAL SYNDROME

DORSAL CARPAL SPRAIN SYNDROME seeDORSAL CARPAL SYNDROME

DORSAL CARPAL SPRAIN-FRACTURE SYNDROME seeDORSAL CARPAL SYNDROME

DORSAL CARPAL SUBLUXATION see DORSALCARPAL TRANSLATION

DORSAL CARPAL SYNDROME

SYNONYMS: dorsal carpal impingement syndrome, dorsal carpalsprain syndrome, dorsal carpal sprain-fracture syndrome

CLINICAL: this syndrome covers a wide variety of damage to the dor-sal carpus from avulsion or tension fractures of ligament insertions,with their frequent residua of ununited chips, exostotic spurs, andthickened impinging scars, to contact damage at capsular-cartilage-bone interfaces subjected to repetitive shear or compression stresses.Stripping of capsular and Sharpey fibers, ridging of osseous margins,chondromalacic changes of cartilage—any or all of these may occurand in some special instances, e.g., “gymnast’s wrist,” a ganglion re-sponse may also be present. Although probably more common at theradiocarpal junction, particularly between radius and scaphoid or ra-dius and lunate, these reactions also occur between components ofthe proximal and distal carpal rows and, between components of thecarpus and the metacarpus.

RADIOLOGIC: a standard motion series of PA views (neutral, radialdeviation, and ulnar deviation) and lateral views (neutral, extension,and flexion) will usually show osseous deformity, but tomography,bone scintigraphy, and MRI may be needed to confirm clinical suspi-cion. OTHER DIAGNOSTIC MODALITIES: Arthroscopy may showintra-articular and even margin lesions, but some of these dorsal car-pal syndromes are so devoid of dramatic findings that surgery may beindicated only by symptom degree, localized tenderness, or palpableabnormality and provocative maneuver, with the pathology only fi-nally revealed by the surgical examination itself.

COMMENTS: 1) variants of this syndrome, such as “carpe bossu,” inwhich the principal tension is provided by the ECRB (extensor carpiradialis brevis) insertion, and “boxer’s boss,” in which the principalforce vector is provided by repetitive compression stress, are suffi-ciently unique to have acquired a specific name. 2) Although viewedby some as invalid or self-healing conditions (and many, such as thecommon dorsal triquetral avulsion fracture, are self-healing), thisgroup of injuries overall is one of the most common diagnoses seenin the post-traumatic carpus. Only its propensity for self-healing orat least healing to a low level of symptoms has kept this diagnosisfrom the notoriety that it deserves. 3) This entity includes DORSALRADIOCARPAL IMPACTION SYNDROME, where the abnormalityis at the radiocarpal level.

CODE: Clinical Conditions: Compression-Impaction (IIIE)

REFERENCES: 1. Dobyns JH, Sim FH, Linscheid RL. Sports stress syndromes of the hand and

wrist. Am J Sports Med. 1978;6:236-54.

2. Dobyns JH, Linscheid RL. Complications of treatment of fractures and disloca-tions of the wrist. In: Epps CH Jr, editor. Complications in orthopedic surgery. Philadelphia: Lippincott; 1978. p 271-352.

3. Weinzweig J, Watson HK. Wrist sprain to SLAC wrist: a spectrum of carpal in-stability. In: Vastamaki M, Vilkki S, Raatikainen T, Viljakka T, editors. Current trends in hand surgery. Proceedings of the 6th Congress of the International Federation of Societies for Surgery of the Hand (IFSSH), Helsinki, 1995 July 3-7. New York: Elsevier; 1995. p 47-55.

DORSAL CARPAL TRANSLATION (DCT) (FIGURE 28)

SYNONYMS: dorsal carpal translocation, dorsal carpal subluxation,dorsal radiocarpal translocation or subluxation

Fig. 27b

Fig. 27a

DISTAL RADIOULNAR (DRUJ) SUBLUXATION: a) axial CT images of both

overpronated wrists in two different patients show a normal DRUJ joint

relationship, and b) widening of the left (L) DRUJ (between black arrows)

with associated soft tissue swelling (white arrows). (Reprinted with per-

mission from Gilula LA, Yin Y, editors. Imaging of the wrist and hand.




CLINICAL: abnormal dorsal shift of the entire carpus in relationshipto the long axis of the radius

RADIOLOGIC: on lateral radiographs of the wrist, the lunate and therest of the carpus is translated dorsally with respect to the long axis ofthe radius, and there is loss of parallelism between the opposing ar-ticular surfaces of the radius and lunate.

COMMENTS: 1) this may be pathologic from acute ligament disrup-tion or may develop chronically as an adaptive response to an alteredtilt (increased extension) of the distal radius articular surface, post-fracture. 2) When secondary to the adaptive carpus (see ADAPTIVECARPUS) following a dorsally impacted distal radius fracture, the lu-nate will usually tip dorsally before translating dorsally, but both mayoccur. 3) Like the other carpal malalignments, DCT may present as astatic deformity or may present only dynamically with some provoca-tive stress.


REFERENCE:1. see DORSAL INTERCALATED SEGMENTAL INSTABILITY (DISI)

DORSAL CARPAL TRANSLOCATION see DORSAL CARPALTRANSLATION

DORSAL COLLAPSE see DORSAL INTERCALATEDSEGMENTAL INSTABILITY (DISI)

DORSAL INTERCALATED SEGMENTAL INSTABILITY (DISI)(FIGURE 29; SEE ALSO FIGURES 14, 15)

SYNONYMS: concertina collapse deformity (Fisk), zigzag collapsedeformity, dorsal intercalary segmental instability, dorsal collapse

CLINICAL: a carpal instability characterized by proximal and dorsalmigration of the bones of the distal carpal row, associated with exten-sion and often palmar translation of the lunate with the metacarpalsin line with the distal radius

Fig. 28

DORSAL CARPAL TRANSLATION (DCT): the proximal articular sur-

face of the carpus as recognized by the proximal convexity of the

lunate is located dorsal to the midportion of the distal radius with

the hand and wrist in the neutral position. The SPC relationship is

excellent (see NEUTRAL LATERAL VIEW). Old fracture deformity

with dorsal inclination of the distal articular surface involves the

radius. (Reprinted with permission from Gilula LA, Yin Y, editors.

Imaging of the wrist and hand. Philadelphia: WB Saunders; 1996.

p 212. Fig 8-11.)

Fig. 29a

DORSAL INTERCALATED SEGMENTAL INSTABILITY (DISI): a) lateral

view: the lunate is tilted dorsally and lies along the ventral surface of

the distal radius. The scapholunate angle is increased to more than

80° and the capitolunate angle is more than 30°. The ventral rim of

the distal radius is fractured (arrow). b) Posteroanterior view: the

lunate has a triangular shape indicative of lunate tilting. A transverse

fracture of the radial styloid is present. c) This three-part drawing dem-

onstrates on the left drawing that with DISI, as the lunate tilts dorsally

(left curved arrow), the lunate may move ventrally (short straight arrow

pointing to the right), the capitate tends to move dorsally (straight

arrow passing to the left), and the scaphoid tilts palmarly (curved

arrow to the right). As a result there is an increased scapholunate

angle of more than 80° (middle drawing) and/or an increased capitolu-

nate angle of more than 30° (drawing to the right). S = scaphoid axis,

L = lunate axis, and C = capitate axis. (Reprinted and modified with

permission from Gilula LA, Yin Y, editors. Imaging of the wrist and

hand. Philadelphia: WB Saunders; 1996. p 216. Fig 8-16B.)



RADIOLOGIC: on a lateral radiograph centered on the wrist, withthe wrist in neutral flexion/extension and pronosupination, the lu-nate is dorsiflexed with regard to the long axis of the radius, by 15° ormore. The diagnosis of DISI is made with the wrist in neutral posi-tion identifying a capitolunate angle of more than +30°, usually ac-companied by an equivalent –15° angle at the radiolunate joint. Thescapholunate angle, which may be abnormal in some DISI situations,is considered abnormal when >80°, and is of questionable signifi-cance when between 60-80°. Also, DISI should have abnormal inter-carpal motion. On lateral views of the wrist, the failure of the midaxis of the capitate to flex and extend with respect to the mid axis ofthe lunate, and the mid axis of the lunate to flex and extend with re-spect to the mid axis of the radius with flexion and extension of thewrist respectively, may be used as an indicator of abnormal intercar-pal motion (see reference #3).

COMMENTS: 1) see CID-DISI and CIND-DISI. 2) Comparisonwith the unaffected side is always important in that 10° or more dif-ference is usually clinically meaningful. 3) Dorsal shift of the distalcarpal row can be quantified by the RCA (radius-carpal axis)-to-capitate distance. 4) In compression, the proximal carpal row acts as

an intercalated segment between two relatively fixed structures (themetacarpals/distal carpal row and the radius) and moves palmarlyor dorsally, unless controlled by an intact musculoligamentous sys-tem. When the proximal row displaces palmarly and tilts dorsally, asvisualized by the lunate on lateral roentgenograms, the displace-ment is called DISI. 5) In the DISI with SLD (scapholunate dissocia-tion) the scaphoid is palmar flexed, but in CIND-DISI the entireproximal carpal row is dorsiflexed. 6) To separate DISI from rotarysubluxation of the scaphoid, the lunate motion should be evaluated.With typical DISI having an increased scapholunate angle, the lu-nate will have abnormal motion on flexion/extension lateral viewsand radial and ulnar deviation lateral views. Using these same views,the lunate motion will be normal with isolated rotary subluxation ofthe scaphoid. 7) Some DISI deformities may not seem unstable orpathologic, since the position may be relatively fixed, although theremay still be progression at a slower pace. 8) Within the proximalcarpal row, the lunate may be abnormally aligned alone (rare),bonded with one of the other of its proximal carpal row neighbors(most commonly, the scaphoid), or bonded and extended with bothof its PCR neighbors as in CIND-DISI.


REFERENCES: 1. Linscheid RL, Dobyns JH, Beabout JW, Bryan RS. Traumatic instability of the


2. Dobyns JH, Berger RA. Dislocations of the carpus. In: Chapman MW, Madison M, editors. Operative orthopedics. 2nd ed, vol 2. Philadelphia: JB Lippincott; 1993. p 1289-305.

3. Gilula LA, Weeks PM. Post-traumatic ligamentous instabilities of the wrist. Radiology. 1978;129:641-51.


DORSAL MIDCARPAL INSTABILITY see CAPITOLUNATEINSTABILITY PATTERN

DORSAL RADIOCARPAL IMPACTION SYNDROME seeDORSAL CARPAL SYNDROME

DORSAL RADIOCARPAL TRANSLOCATION/SUBLUXATION seeDORSAL CARPAL TRANSLATION

DORSOPALMAR PROJECTION/POSITION seePOSTEROANTERIOR VIEW

DORSOVOLAR PROJECTION/POSITION seePOSTEROANTERIOR VIEW

DORSOVOLAR TRIQUETROLUNATE TRANSLATION/DISPLACEMENT TEST see TRIQUETROLUNATE BALLOTTEMENT

DYNAMIC INSTABILITY (SEE FIGURE 6)

SYNONYMS: stress instability, intermittent instability

CLINICAL: this is a malalignment shown only on radiographs madeduring or after stress provocation of the wrist.

RADIOLOGIC: a situation in which nonstressed neutrally positionedposteroanterior and lateral views (i.e., no flexion or extension, no ra-dial or ulnar deviation, no pronosupination) are normal, while someother hand position or provocative maneuver (PM) may demonstratemalalignment

Fig. 29b

Fig. 29c



COMMENTS: 1) some people divide dynamic instability into twosubgroups: Dynamic 1 = no radiologic changes at all, and Dynamic2 = the definition described here under RADIOLOGIC. Other peopledo not accept this subgroup classification of Dynamic 1 and 2. Someuse “dynamic” and “static” instability as classifications in themselves;most use the terms only as stages of a major classification, i.e., SLDmay be subclassified for treatment purposes between several stages,three of which might be dynamic, static reducible, and static irreduc-ible. 2) The effective provocative maneuver may be as simple as per-forming some element of wrist motion or making a fist. 3) Someexperts have difficulty with the terms “static” and “dynamic.” As oneexpert states: “An instability is always dynamic. A ‘static’ instability isa contradiction, if we analyze the words correctly.” 4) Some expertsbelieve very strongly that the term “instability” should be used onlyin patients who have abnormal alignment that is associated with ab-normal carpal motion (see reference #4).


REFERENCES:1. Dobyns JH, Linscheid RL. Fractures and dislocations of the wrist. In: Rock-



3. Taleisnik J. Classification of carpal instability. Bull Hosp Dis Orthop Inst. 1984;44:511-31.


FIXED CARPAL INSTABILITY see STATIC CARPAL INSTABILITY

FLEXION INSTABILITY see VOLAR INTERCALATED SEGMENT INSTABILITY (VISI)

FRACTURE-DISLOCATION (FIGURE 30)

SYNONYM: fracture-luxation

CLINICAL: a condition represented by a break in one or more boneswith an accompanying complete disruption of one or more joints inthe wrist such that usually congruent articular surfaces no longercontact one another


COMMENTS: along with its sibling, fracture-subluxation, i.e., a par-tial dislocation with associated fractures, this is considered by somewrist experts as the third category of carpal instability.


REFERENCE:1. see DYNAMIC INSTABILITY

FRACTURE-LUXATION see FRACTURE-DISLOCATION

FRACTURE-SUBLUXATION (FIGURE 31, SEE ALSO FIGURE 20)

SYNONYM: fracture with partial dislocation (see comment #2)

CLINICAL: a condition represented by a break in one or morebones with an accompanying partial joint disruption, so the nor-mally contiguous joint surfaces are now only partially in contactwith one another


COMMENTS: 1) along with its sibling, fracture-dislocation, this is

Fig. 30b

Fig. 30a

FRACTURE-DISLOCATION: a) PA view: the scaphoid and lunate (proxi-

mal arrowheads) with a bone fragment (arrows) related to the lunate

overlap the radius (distal arrowheads). The lunate and triquetrum

overlap the distal radius and ulna. All the carpal bones are normally

related to each other. These features indicate a fracture, probably

from the radius, which is associated with a dislocated carpus.

b) The lateral view demonstrates palmar and proximal dislocation of

the carpus with a fragment from the palmar rim of the distal radius,

most likely from the lunate fossa, as the fragment moves with the

lunate. This case can be called transradial palmar carpal fracture-

dislocation. (Reprinted with permission from Gilula LA, Yin Y, editors.

Imaging of the wrist and hand. Philadelphia: WB Saunders; 1996.

p 211. Fig 8-10, A and B.)



considered by some wrist experts as the third category of carpal in-stability (see comment #4 under MIDCARPAL SUBLUXATION). 2)The terms “dislocation” and “subluxation” refer to the conditionpresent at the joint and not at the bone fracture site.


REFERENCE:1. see DYNAMIC INSTABILITY

FRACTURE WITH PARTIAL DISLOCATION seeFRACTURE-SUBLUXATION

FRONTAL see ANTEROPOSTERIOR VIEW seePOSTEROANTERIOR VIEW

FRONTAL CARPAL CONDYLE ANGLE see CARPAL ANGLE

GAP see DIASTASIS

GILULA’S ARCS see CARPAL ARCS

GREATER ARC INJURY (FIGURE 32) see PERILUNATE

FRACTURE-DISLOCATION; LESSER ARC INJURY;COMBINATION ARC INJURY

SYNONYMS: transscaphoid, transcapitate, transtriquetral perilunateinjuries (see COMMENTS)

CLINICAL: 1) a summary term to describe the radial to ulnar dis-ruption patterns through the scaphoid and capitate bones and liga-ment(s) at some distance from the lunate. 2) This is an injury alongthe “greater arc” of the carpus. As originally described, this injury arcis projected across the mid scaphoid, capitate head or neck, and lu-nate articulation of the triquetrum with or without fracture of theproximal pole of the hamate (per input from Dr. Roger Johnson).(See REFERENCES and see comment #1).


COMMENTS: 1) this classification of injuries is described only as acarpal injury pattern and as originally described does not include frac-tures of the radius (radial styloid) or ulna (ulnar styloid). Fractures ofthe radial and ulnar styloid processes may be associated with greateror lesser arc injuries, but as originally described are not part of theclassification of greater and lesser arc injuries. 2) COMBINATIONARC INJURIES include any injury of the carpus that are between aLESSER ARC INJURY and a full GREATER ARC INJURY. 3) Exam-ples of this injury are transscaphoid transcapitate fracture dislocation;transscaphoid, transcapitate, transtriquetral fracture dislocation; andtransscaphoid, transcapitate, transhamate, transtriquetral fracturedislocation. 4) Some experts believe that the only value of recognizingthe pattern of the greater (and lesser) carpal arc(s) is to realize the un-derlying mechanism of injuries, and that the exact description of theanatomic abnormalities is more important when describing the ab-normality present. 5) These include transosseous perilunate injuries,as opposed to ligament-only perilunate injuries. See above comment#2 as regards separation of the greater arc injury from the combina-tion arc injury. 6) See COMMENTS in LESSER ARC INJURY.

Fig. 32

GREATER AND LESSER ARC INJURIES: “A” refers to the greater arc, “B”

refers to the lesser arc, and “C” refers to the radiolunate joint through

which injury also takes place with a lunate dislocation. The vulnerable zone

of the carpus is represented by the shaded area. Irregular lines in the carpal

bones represent sites of potential fractures. See text. (Reprinted with per-

mission from Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Phila-

delphia: WB Saunders; 1996. p 306. Fig 11-20.)

Fig. 31

FRACTURE-SUBLUXATION: a sagittal plane CT section through the

fourth metacarpal (4), hamate (H), and ulna (U) shows a fracture

(black arrowheads) through the base of the fourth metacarpal. The

fracture fragments are separated above the distal articular surface of

the hamate, and the dorsal surface of the fourth metacarpal (arrows)

is subluxed dorsally with respect to the dorsal surface of the hamate

(white arrowhead).




REFERENCES: 1. Johnson RP. The acutely injured wrist and its residuals. Clin Orthop. 1980;

149:33-44.

2. Mayfield JK. Mechanism of carpal injuries. Clin Orthop. 1980;149:45-54.

3. Mayfield JK, Johnson RP, Kilcoyne RK. Carpal dislocations: pathomechanics and progressive perilunar instability. J Hand Surg [Am]. 1980;5:226-41.

HAMATE FACET OF THE LUNATE see LUNATE, TYPES I AND II

HAND-WRIST FRACTURE DISLOCATION see CARPOMETACARPALFRACTURE-DISLOCATION

HOMING-IN PHENOMENON see CATCH-UP CLUNK

HOOK OF HAMATE VIEW see SEMISUPINATED OBLIQUE VIEW

HYPOTHENAR see ULNAR

IMPACTION, DORSAL RADIOCARPAL see DORSALCARPAL SYNDROME

IMPACTION SYNDROME, DORSAL RADIOCARPAL seeDORSAL CARPAL SYNDROME

IMPACTION SYNDROME, ULNOCARPAL (FIGURE 33)

SYNONYMS: ulnocarpal abutment, ulnar impaction syndrome, ul-nar impingement (not preferable—see COMMENTS)

CLINICAL: a syndrome characterized by ulnar-sided wrist pain pro-duced by the grip-loaded movements of ulnar deviation and rotationof the forearm/wrist unit (often with supination). It is thought to oc-cur when there is abnormal load borne by the ulnar axis, and it mayvary from mild to severe. It is associated with degenerative changes inthe contact surfaces of the lunate, ulnar dome (distal end of theulna), the intervening TFC (triangular fibrocartilage), and occasion-ally the triquetrum (see comment #1).

RADIOLOGIC: on conventional posteroanterior radiographs, neu-tral or positive ulnar variance is usually seen. There may be associ-ated arthritic or lucent (“cyst-like”) changes in the osseous structureof the ulnar side of the lunate, radial side of the ulnar dome (distalend of the ulna), and the triquetrum. On arthrography (including to-mography “cuts”), MRI, or arthroscopy, chondromalacia of these ar-ticular surfaces is often associated with LT (lunotriquetral) andcentral TFC perforations.

COMMENTS: 1) ulnocarpal impaction can occur with only patho-logic cartilage changes (chondromalacia) and no osseous changes. 2)Occasionally this may be seen with ulnar negative variance with forcestransmitted through the TFC. 3) This may be related to chronic physi-ologic distal migration of the radius as the radius moves from a moreproximal position during pronation to a more distal position duringsupination. 4) Radiographic changes of ulnocarpal arthrosis may occurwithout pain, especially in some elderly persons. Without pain, thisshouldn’t be considered as the ulnar impaction syndrome and may bedue to aging or “senescent changes.” 5) The terms “ulnar impinge-ment” or “ulnocarpal impingement” are sometimes used for this con-dition, but “ulnar impingement” is preferentially used for the ulnarstump-adjacent radius syndrome, possibly more clearly called “distalradioulnar impaction.” The use of the words “ulnocarpal impaction”also eliminates any question about the site of distal ulnar impaction orimpingement. 6) It is the opinion of at least one expert that currently itis unknown what part a TFC tear or defect plays in producing the painof ulnocarpal impaction syndrome. If pain were related only to a TFCtear, it could be questioned if the condition should be called “ulnocar-pal impaction syndrome.”


REFERENCES: 1. Dobyns JH, Linscheid RL. Fractures and dislocations of the wrist. In: Rock-


2. Friedman SL, Palmer AK. The ulnar impaction syndrome. Hand Clin. 1991;7:295-310.

IMPINGEMENT, RADIOULNAR (DISTAL) (FIGURE 34)

SYNONYMS: radioulnar compression or abutment syndrome, distalradioulnar impaction

CLINICAL: NA

RADIOLOGIC: a condition leading to distal radioulnar arthrosis inwhich the ulnar head converges to, articulates with, and impinges onthe radius, typically proximal to a horizontally inclined distal radiussigmoid fossa

COMMENTS: 1) some physicians use “impingement” and “impac-tion” interchangeably. However, “impingement” refers more generallyto the ulna abutting the side of the radius, and “impaction” refers tothe ulna abutting the carpus. Probably the safest way to clearly definethe impaction or impingement is to specify the site of the impaction,impingement, or abutment, e.g., ulnocarpal or distal radioulnar. 2)Impingement may occur between the distal ulnar stump and the adja-

Fig. 33

IMPACTION, ULNOCARPAL: on this PA view, flattening (distal arrow-

heads) and subchondral sclerosis of the proximal ulnar surface of

the lunate with similar flattening (proximal arrowheads) and sub-

chondral sclerosis of the distal end of the ulna represent impaction

between the ulna and the opposing surface of the lunate. Loss of

normal cortical medullary junction of the proximal radial corner of

the triquetrum supports reaction from ulnocarpal impaction at this

site also. (Reprinted with permission from Gilula LA, Yin Y, editors.

Imaging of the wrist and hand. Philadelphia: WB Saunders; 1996. p

525. Fig 20-4)



cent radius post distal ulnar resection or Sauvé-Kapandji procedure.


REFERENCES:1. Cooney WP 3rd, Linscheid RL, Dobyns JH. Fractures and dislocations of

the wrist. In: Rockwood CA Jr, Green DP, Bucholz RW, Heckman JD, editors. Fractures in adults. 4th ed, vol 1. Philadelphia: Lippincott-Raven; 1996. p 745-867.

2. Watson HK, Brown RE. Ulnar impingement syndrome after Darrach procedure: treatment by advancement lengthening osteotomy of the ulna. J Hand Surg [Am]. 1989;14:302-6.

INSTABILITY (SEE FIGURES 13, 14, 15, 16, 29)

SYNONYMS: destabilization, loss of stability

CLINICAL: 1) the opposite of stability. 2) A condition represented bythe inability to maintain, or an actual loss of normal alignment ofcarpal bones under physiologic loads (see comments #3 and #4). It isa corollary that instability alters normal carpal kinematics (seeSTATIC CARPAL INSTABILITY). 3) A condition in which normalanatomic relationships are present, but through some provocativemaneuver, such as external stress, muscle contracture, or positioning,an abnormal relationship can be demonstrated. Once this stresspositioning or contracturing stops, the parts (usually bones) can bereturned to their normal anatomic positions (see DYNAMIC IN-

STABILITY). Such abnormal positions are called subluxation if theyare not extreme enough to fit the definition for a “dislocation” or a“fracture-dislocation.”

RADIOLOGIC: the abnormal carpal position or arc of motion can bedocumented using non-stress and stress (provocative) maneuverswith various imaging techniques to confirm the diagnosis. The ab-normal alignment may be between adjacent carpal bones, betweencarpal bones and the radius, between the distal radius and ulna, orbetween the carpus and the metacarpus.

COMMENTS: 1) Major controversy exists among experts about theuse of this term. Some strongly believe that malalignment does notnecessarily mean instability is present and that “malalignment” is nota synonym for “instability” (see reference #3). 2) Static “instability” ismalalignment present on neutral PA and lateral radiographs withoutprovocative stress. For clinical purposes, static instability is some-times further divided into reducible and irreducible malalignment.Dynamic malalignment (“instability”) is a malalignment presentonly on stress radiographs or with other provocative examinations.3) Some malalignments that fit the criteria for a static instability withabnormal kinematics may actually be constantly in a “fixed” or rela-tively “stable” position. Even so, they have progressed from the nor-mal and may progress further. 4) A provocative maneuver may showphysiologic laxity, a condition that has nothing to do with a wrist in-stability. 5) Some experts do not like this term to be used when themalalignment is fixed and not reducible. However, this may be con-sidered a spectrum of conditions starting from a symptomatic condi-tion not shown by imaging tests or clinical findings to one shown byimaging tests and clinical findings and finally to a fixed deformity.Some of these experts feel very strongly that the term “instability”should be used only in the patients who have abnormal alignmentthat is associated with abnormal carpal motion (see reference #3). 6)Currently, this is a term in evolution. With continual growth inknowledge, this term will continue to be modified.


REFERENCES: 1. Linscheid RL, Dobyns JH, Beabout JW, Bryan RS. Traumatic instability of the


2. Dobyns JH, Linscheid RL, Chao EYS, Weber ER, Swanson GE. Traumatic insta-bility of the wrist. AAOS Instr Course Lect. 1975;24:182-99.


INTACT see COMPETENT

INTERCALATED CARPAL ROW see PROXIMAL CARPAL ROW

INTERMITTENT INSTABILITY see DYNAMIC INSTABILITY

LATERAL (FIGURE 35) see RADIAL, THENAR

SYNONYMS: varies for direction, as radial or thumbward; and plane,as sideview, sagittal, or dorsovolar for anatomic or radiographic plane

CLINICAL: 1) further from the midline of the body with the hand inthe anatomic position of supination. 2) Views made from the radialor ulnar side of the hand, wrist, or forearm displaying the osseousstructures in the sagittal or dorsovolar plane. 3) Displacement of adistal segment in a direction away from the midline of the body.

RADIOLOGIC: NA (see LATERAL VIEW)

Fig. 34

IMPINGEMENT, RADIOULNAR (DISTAL): the ulna articulates with the

side of the distal end of the radius (arrowheads). The ulnar aspect of

the distal end of the radius curves ulnarly to cover the distal end of

the radius. Subcortical sclerosis in the radius and ulna at the distal

radioulnar articulation supports reactive bone formation from radioul-

nar impingement. This type of articulation is a congenital variation

that may not have associated symptoms. (Reprinted with permission

from Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadel-

phia: WB Saunders; 1996. p 526. Fig 20-6.)



COMMENTS: lateral, the direction, is often confused with the radio-logic term, LATERAL VIEW (see discussion of this term).

CODE: Radiologic: Sides (IC)

REFERENCE:1. anatomy or radiology textbooks

LATERAL CARPAL COLUMN see RADIAL COLUMN OF THE CARPUS

LATERAL PLANE see SAGITTAL PLANE

LATERAL VIEW (FIGURE 35; SEE ALSO FIGURE 2B)

SYNONYMS: lateral projection/position, sagittal view, side view

CLINICAL: NA (see LATERAL)

RADIOLOGIC: a view of the wrist from either the radial to the ulnaror ulnar to radial side with the metacarpals aligning in the sameplane. The radiographic view should be made with the ulnar (orradial) border of the wrist on the film cassette, and the roentgeno-graphic tube placed directly opposite on the radial (or ulnar) aspect,respectively, of the wrist. An adequate lateral view of the carpus canbe identified with recognition of the SPC relationship: the ventral(volar) surface of the pisiform (“P”) lies between the ventral (volar)cortex of the distal pole of the scaphoid (“S”) and the ventral (volar)cortex of the proximal convexity of the capitate (“C”) to create the“SPC” relationship (see reference #2).

COMMENTS: 1) a lateral view gives a sagittal plane view of the struc-tures. If incremental lateral views across the wrist are made, they areoften called parasagittal views. 2) A lateral plane view in contradis-tinction to a lateral view gives a frontal or AP/PA view of the struc-tures. 3) The SPC relationship identifies the carpus and not the distalforearm alignment.


REFERENCES: 1. radiology textbooks

2. Yang Z, Mann FA, Gilula LA, Haerr C, Larsen CF. Scaphopisocapitate alignment: criterion to establish a neutral lateral view of the wrist. Radiology. 1997;205:865-9.

LESSER ARC DISRUPTION/DISLOCATION see PERILUNATE DISLOCATION (PLD)

LESSER ARC INJURY (SEE FIGURE 32)

SYNONYM: perilunate injury

CLINICAL: a conceptual summary term describing the radial toulnar ligamentous disruption pattern found with perilunate andlunate subluxation or dislocations. This is any dislocation or disso-ciation through ligaments around the lunate with or without radial-sided avulsions of the triquetrum (per personal discussion withRoger Johnson, M.D., original descriptor of this concept) and istherefore more proximal than the GREATER ARC INJURY.

RADIOLOGIC: same as description for perilunate dislocation andlesser stages of perilunate dislocation, such as scapholunate dissocia-tion, lunotriquetral (triquetrolunate) dissociation, etc.

COMMENTS: 1) ligamentous failure occurs at the periphery of thelunate, in other words, at the radiocarpal level radially, perilunate(radial, distal, and ulnar) centrally, and at the radioulnocarpal levelulnar to the lunate. This definition describes the site rather than thespecific injury. 2) Clinically, it is preferable that a specific description

Fig. 35b

Fig. 35a

LATERAL VIEW (see also Figure 2B): a) standard positioning for lateral

view is performed with the elbow flexed 90° and the elbow adducted

against the patient’s side. b) An adequate lateral view of the carpus

can be detected when the ventral cortex of the pisiform (arrow) is pro-

jected between the ventral surfaces of the head of the capitate (right

arrowhead of the double-headed arrow) and the distal pole of the

scaphoid (left arrowhead of the double-headed arrow). This is the SPC

(scaphopisocapitate) lateral as described in the text. The double-

headed arrow shows the distance between the ventral surfaces of the

capitate head and the distal pole of the scaphoid. (Reprinted with per-


Philadelphia: WB Saunders; 1996. p 124-5. Fig 5-30, A and B.)



of fracture/dislocation is provided, as this term does not provide aspecific description of the abnormality present. 3) The term includesthe various levels of perilunate subluxation/dislocation; lunatesubluxation/dislocation; and may include carpal instability com-bined—radiocarpal and perilunate type. 4) Many experts prefer notto use the terms “greater and lesser arc or combination arc injuries.”However, the terms provide shorthand terminology for the mostcommon dislocations of the carpus, the perilunate, and the transos-seous perilunate types. These terms have been accepted and are fre-quently used. 5) At least one expert questions if the greater, lesser,and combination arc injuries as described by Mayfield and Johnsonare clearly defined entities, since their work was performed withoutloading the muscles. 6) Strictly speaking (per input from Dr. RogerJohnson), this lesser arc injury is any dislocation or dissociationaround the lunate with or without radial-sided avulsion of the tri-quetrum (see references in GREATER ARC INJURY). 7) COMBI-NATION ARC INJURIES include any injury of the carpal arcs thatare between a LESSER ARC INJURY and a GREATER ARC INJURY.


REFERENCE:1. see GREATER ARC INJURY

LINKED see NONDISSOCIATION

LONGITUDINAL AXIS (FIGURE 36) see SAGITTAL PLANE

SYNONYM: columnar axis; see comment #2 regarding sagittal axis

CLINICAL: see COMMENTS

RADIOLOGIC: see COMMENTS

COMMENTS: 1) every anatomic structure or group of structures inthis area may have a longitudinal axis. It is a general term that needsto be specifically designated to something each time it is used, i.e., thelongitudinal axis of the scaphoid. 2) “Sagittal axis” is not a true syn-onym of “longitudinal axis,” as sagittal axis is a specific type of longi-tudinal axis, one that is in the same plane as the sagittal suture.



LONGITUDINAL CARPAL DISLOCATION (FIGURE 37)

SYNONYM: axial carpal dislocation

CLINICAL: traumatic injury to the wrist consisting of a longitudinaltransarticular disruption of the metacarpal and carpal transversearches with complete loss of the normal relationship between theparts into which the carpus has been divided. No fractures arepresent.

RADIOLOGIC: complete loss of articular apposition through anydistal row intercarpal joint and the attached metacarpals. There maybe transarticular extension into the proximal carpal row. No fracturesare present.

COMMENTS: 1) see LONGITUDINAL CARPAL INSTABILITY. 2)“Axial” is used in the anatomic sense (parallel to the long axis of theforearm) rather than the biomechanic sense.


REFERENCES:1. Norbeck DH Jr, Larson B, Blair SJ, Demos TC. Traumatic longitudinal disrup-

tion of the carpus. J Hand Surgery [Am]. 1987;12:509-14.

2. Garcia-Elias M, Dobyns JH, Cooney WP 3rd, Linscheid RL. Traumatic axial dislocations of the carpus. J Hand Surg [Am]. 1989;14:446-57.

LONGITUDINAL CARPAL FRACTURE-DISLOCATION/SUBLUXATION (FIGURE 38)

SYNONYM: axial carpal fracture-dislocation

CLINICAL: traumatic injury to the wrist consisting of a combinedtransarticular and transosseous longitudinal disruption of the meta-carpal and carpal transverse arches of the hand with loss of the normalrelationships between the parts into which the carpus has been divided.

RADIOLOGIC: complete loss (dislocation) or partial loss (sublux-ation) of articular apposition through any distal row intercarpaljoint and the attached metacarpals associated with fractures. Theremay be transosseous and/or transarticular extension into the proxi-mal carpal row.

COMMENTS: see LONGITUDINAL CARPAL INSTABILITY. “Axial”is used in the anatomic sense (parallel to the long axis of the forearm)rather than the biomechanic sense.


REFERENCE:1. see LONGITUDINAL CARPAL DISLOCATION

Fig. 36

LONGITUDINAL AXIS: this anatomic section is taken in the sagittal plane (in the plane of the sagittal suture) when the hand is placed in anatomic position, that is, with the palm facing forward. The plane passes between dorsal and ventral surfaces of the wrist. (Case donated by Dr. Rudi Richli, Radiologist, MD Anderson Hospital, Houston, Texas.)



LONGITUDINAL CARPAL INSTABILITY(SEE FIGURES 37 AND 38)

SYNONYM: axial carpal instability

CLINICAL: traumatic injury to the wrist consisting of transarticularand/or transosseous longitudinal disruption of the metacarpal andcarpal transverse arches with partial or complete loss of the normalrelationships between the parts into which the carpus has been di-

vided. There may be transosseous and/or transarticular extensioninto the proximal carpal row. The malalignment is unstable.

RADIOLOGIC: partial or complete loss of articular appositionthrough any distal row intercarpal joint and the attached metacarpalswith or without associated fractures. There may be transosseous and/or transarticular extension into the proximal carpal row. Abnormalwidening between two adjacent bones of the distal carpal row that in-

Fig. 38

LONGITUDINAL CARPAL FRACTURE DISLOCATION/SUBLUXATION: trans-trapezium is an axial-radial fracture dislocation. Trans-hamate, peri-pisiform and peri-hamate, trans-triquetrum are types of axial-ulnar fracture dislocations. (Reprinted and modified with permission from Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saunders; 1996. p 221. Fig 8-21.)

Fig. 37

LONGITUDINAL CARPAL DISLOCATION: axial radial dislocation includes peri-trapezoid and peri-trapezium types. Peri-hamate, peri-pisiform is an

axial-ulnar dislocation. (Reprinted and modified with permission from Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saun-

ders; 1996. p 221. Fig 8-21.)



creases or closes under manipulation in conjunction with abnormalwidening between the bases of the two contiguous metacarpals maybe demonstrated either in standard radiographs or stress views (e.g.,traction or compression views).

COMMENTS: 1) to be strictly correct, disruption of the transversecarpal arch requires involvement of the palmar surface of the carpus.2) To be truly “unstable,” the malalignment should not be in a “fixedstate” and should be truly mobile.



LONGITUDINAL CARPAL SUBLUXATION (SEE FIGURES 37 AND 38)

SYNONYM: axial carpal subluxation

CLINICAL: traumatic injury to the wrist consisting of a longitudinalsubluxation of the metacarpal and carpal transverse arches with par-tial loss of the normal relationship between the parts into which thecarpus has been divided

RADIOLOGIC: loss of congruence without dislocation between twoor more carpal bones and their attached metacarpals

COMMENTS: 1) see LONGITUDINAL CARPAL INSTABILITY andLONGITUDINAL CARPAL FRACTURE-DISLOCATION/SUBLUX-

ATION. 2) It is the mildest type of longitudinal carpal malalignment.3) Such a subluxation could be stable in the displaced position or grosslyunstable. If grossly unstable, then that would be a true instability.



LONGITUDINAL (COLUMNAR) INSTABILITY PATTERN (SEE FIGURE 21)

SYNONYM: axial carpal instability

CLINICAL: a concept introduced originally by Navarro that providesa different viewpoint in understanding carpal instability problems. Itis based on three columns: (1) the radial or support column; (2) thecentral or flexion-extension column; and (3) the ulnar or rotationalcolumn. This concept emphasizes the longitudinal interactions of thecarpus with the forearm and hand.


COMMENTS: 1) two types of this pattern would be scapholunateinstability and lunotriquetral (triquetrolunate) instability. 2) This isprincipally of historical interest. Many reviewers of this work believedthat this term should be dropped. 3) Some experts believe that thismay now be considered synonymous with axial carpal instability. 4)There is some disagreement among experts about which bones be-long to which column. This concept emphasizes the longitudinal in-

Fig. 39b

Fig. 39a

LUNATE DISLOCATION: a) the lunate is triangular, indicating that it is

tilted. There is no parallelism between the margins of the lunate and

its adjacent carpal bones (scaphoid, capitate, hamate, and triquetrum).

The lunate overlaps the capitate, hamate, and triquetrum. Parallelism

of cortices between the scaphoid, capitate, trapezium, hamate, and tri-

quetrum and at the fifth carpometacarpal (CMC) joint indicates that these bones have stayed (moved) together. Parallelism at the third and

fourth CMC joints is not well seen because the palm is not flat in this view. All these findings demonstrate dislocation between the lunate

and the rest of the carpal bones. b) On lateral view, the lunate has dislocated ventrally and the capitate head (arrowheads) is centered over

the distal radius, resulting in the diagnosis of ventral lunate dislocation. This case is part of the perilunate spectrum of abnormality as

described in the text. (Reprinted and modified with permission from Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB




teractions of the carpus with the forearm and hand.


REFERENCES: 1. Navarro A. La fisiologia del carpo. An Inst Clin Quirurg Chirurgia Exp. 1937;

6:199-232.


LUNATE DISLOCATION (FIGURE 39)

SYNONYM: radiolunate dislocation

CLINICAL: complete loss of articulation of the lunate with the distalradius and its carpal articulations

RADIOLOGIC: same as CLINICAL. The carpal bones normally sur-rounding the lunate may be in relatively normal relationship with theradius, or they too may be subluxed/dislocated with reference to theradius.

COMMENTS: 1) this is considered by many experts as the last stageof perilunate dislocation. 2) In most instances, perilunate disruptionprecedes lunate dislocation. 3) There may be two types of lunate dis-location. The common type is simply the end stage of “perilunatedislocation” and both radial and ulnar columns are also unstablewith loss of articulation between these columns and the radius. The-oretically, there may be another type with the lunate dislocated fromthe radius without significant damage to the support ligaments of theradial and ulnar columns. However, this has not yet been shown inthe literature. For surgical reconstruction purposes, the differencesbetween the two could be significant. 4) Lunate position in disloca-tion is usually volar (palmar), but may be dorsal, radial, ulnar, orcompletely displaced outside the wrist boundaries. 5) A lunate dislo-cation is a LESSER ARC INJURY.


REFERENCE:

1. Dobyns JH, Linscheid RL. Fracture and dislocations of the wrist. In: Rockwood CA Jr, Green DP, editors. Fractures. Vol 1. Philadelphia: JB Lippincott; 1975. p 345-440.

LUNATE, TYPES I AND II (FIGURE 40)

SYNONYM: lunates with or without hamate facets

CLINICAL: NA

RADIOLOGIC: a congenital variation in the shape of the distal ulnaraspect of the lunate related to presence of a distal ulnar articular sur-face to articulate with the hamate. The Type I lunate is a lunate with-out a radiologically visible hamate articular surface (facet) of thelunate. The Type II lunate is a lunate with a radiologically visiblehamate facet of the lunate. Often the Type II lunate has a broken car-pal arc II at this hamate facet of the lunate (see reference #1).

COMMENTS: 1) chondromalacia may occur in the proximal pole ofthe hamate and the hamate facet of the lunate, and by arthroscopy thisappears to be a common area of early midcarpal arthritis. 2) Antuna-Zapico as well as Stanley and Trail have described various config-urations of the lunate, which may be of importance relative to otherproblems, i.e., Kienböck’s disease and proximal carpal row stability,respectively.


REFERENCES: 1. Viegas SF, Wagner K, Patterson R, Peterson P. Medial (hamate) facet of the lu-

nate. J Hand Surg [Am]. 1990;15:564-71.

2. Antuna-Zapico JM. Malacia del semilunar (tesis doctoral). Valladolid: Univer-sidad de Valladolid; 1966.

3. Stanley JK, Trail IA. Carpal instability. J Bone Joint Surg Br. 1994;76:691-700.

LUNOTRIQUETRAL BALLOTTEMENT see TRIQUETROLUNATEBALLOTTEMENT

LUNOTRIQUETRAL DISSOCIATION (LTD) (SEE FIGURE 13)

SYNONYMS: lunatotriquetral dissociation, triquetrolunate dissocia-tion (see COMMENTS)

CLINICAL: incompetence of the intrinsic and extrinsic ligament(s)supporting the lunotriquetral articulation causing an abnormal rela-tionship between the lunate and triquetrum

Fig. 40a

LUNATE, TYPES I AND II: a) type I lunate shows no evident hamate

facet of the lunate. b) Type II lunate shows an articulation for the

proximal end of the hamate in the distal ulnar aspect of the lunate

(arrowheads).

Fig. 40b



RADIOLOGIC: the spectrum of symptomatic LTD is such that theremay be no radiographic abnormality on standard radiographs orsuch may be demonstrated only with a provocative maneuver.Whether demonstrated dynamically or statically, the direct findingsinclude abnormal disruption of carpal arcs I and/or II on a neutralPA or AP radiograph (see CARPAL ARCS) and an abnormal rotarypositioning between the lunate and triquetrum on lateral radio-graphs. The arthrographic demonstration of a communicating LTligamentous defect is a common associated finding; however, com-municating defects of the lunotriquetral ligament may be presentwithout abnormal alignment or kinematics at this joint; conversely,the intracarpal lunotriquetral ligament (membrane) may be incom-petent without an overt tear.

COMMENTS: 1) a part of the spectrum of CID-VISI. 2) Malalign-ment of the lunate and triquetrum may be perceptible only duringthe stress of movement, compression, etc. 3) It may be due to or ag-gravated by direct trauma, inflammation, or congenital looseness ofthe ligaments supporting the articulation found between the twocarpal bones. 4) A more advanced stage of LTD will show a staticCID-VISI with both scaphoid and lunate flexed, and the triquetrumneutral or extended. With further progression by involvement of theextrinsic or capsular ligaments, the deformity becomes severe andeventually fixed. It becomes a CIC (carpal instability combined) typelesion at this stage. 5) With lunotriquetral “sprain,” there may not besufficient disruption of these ligaments to show characteristic radio-logic findings. Some people believe that “sprain” is due to or associ-ated with ulnar impaction syndrome; however, objective criteria todiagnose a “sprain” have not been established for general acceptance.6) This is a spectrum of injury (just as is scapholunate dissociation)that includes lunotriquetral ligament disruptions without overt in-stability but painful instabilities both by the patient’s and the physi-cian’s evaluations. Early, this may occur without VISI, and finally thestatic VISI deformity may be present. 7) Lunotriquetral dissociationis one stage of LESSER ARC INJURY.


REFERENCES: 1. Reagan DS, Linscheid RL, Dobyns JH. Lunotriquetral sprains. J Hand Surg

[Am]. 1984;9:502-14.

2. Taleisnik J. Classification of carpal instability. Bull Hosp Jt Dis Orthop Inst. 1984;44:511-31.

3. Horii E, Garcia-Elias M, An KN, Bishop AT, Cooney WP, Linscheid RL, Chao EY. A kinematic study of luno-triquetral dissociations. J Hand Surg [Am]. 1991;16:355-62.

LUNOTRIQUETRAL (TRIQUETROLUNATE) INSTABILITY seeLONGITUDINAL (COLUMNAR) INSTABILITY PATTERN;LUNOTRIQUETRAL DISSOCIATION

LUXATION see DISLOCATION

McMURTRY’S CARPAL ULNAR DISTANCE RATIO seeMcMURTRY’S INDEX

McMURTRY’S INDEX (FIGURE 41)

SYNONYM: McMurtry’s carpal ulnar distance ratio

CLINICAL: a measurement to detect ulnar carpal translation or trans-location (see ULNAR TRANSLATION)

RADIOLOGIC: on the PA radiograph of the wrist, a line is drawndown the mid axis of the ulna (UA-ulnar axis). The length of the thirdmetacarpal (L1) is measured. The distance between the center of the

head of the capitate and AU (central axis of the ulna) is called L3. L3divided by L1 = 0.3 + 0.03. This measurement is McMurtry’s Index.

COMMENTS: 1) McMurtry’s name is also associated with carpalheight, carpal height ratio, and carpal height index (see CARPALHEIGHT). 2) See ULNAR TRANSLOCATION/TRANSLATION OFTHE CARPUS.


REFERENCE:1. McMurtry RY, Youm Y, Flatt AE, Gillespie TE. Kinematics of the wrist. II. Clinical

applications. J Bone Joint Surg Am. 1978;60:955-61.

MEDIAL

SYNONYMS: ulnar, ulnarward, mesial

CLINICAL: 1) closer to the midline of the body with the hand andwrist in the anatomic position (supination); 2) displacement or an-gulation of the distal segment toward the midline of the body withthe hand-wrist-forearm in supination.


COMMENTS: 1) “ulnar” or “medial” is an adjective, not a noun. 2)It is recommended that the term “medial” be avoided whenever themeaning of “ulnar” is being used, in order to minimize the chance ofmisusing the word “medial.” However, “ulnar” is used not only to in-dicate direction but also that something, i.e., a “styloid”, is a part ofthe ulna. So deceptive is this usage that at least one expert uses theterm, “ulna styloid” rather than “ulnar styloid.” 3) See COMMENTSunder RADIAL.


REFERENCE:1. Hollinshead WH. Textbook of anatomy. 3rd ed. New York: Harper and Row;

1974.

Fig. 41

McMURTRY’S INDEX

(see text): L1 is the

length of the third

metacarpal; L2 is car-

pal height, and L3 is the

distance between the

center of the head of

the capitate and AU

(central axis of the

ulna). L3/L1 = 0.3 +

0.03. (Reprinted with

permission from Gilula

LA, Yin Y, editors.

Imaging of the wrist

and hand. Philadelphia:

WB Saunders; 1996.

p 208. Fig 8-6B.)



MEDIAL ANTERIOR MIDCARPAL INSTABILITY (MAMI) see TRIQUETROHAMATE INSTABILITY

MEDIAL COLUMN see ROTARY COLUMN

MEDIOCARPAL JOINT see MIDCARPAL JOINT

MESIAL see MEDIAL

MIDCARPAL DISLOCATION (FIGURE 42)

SYNONYM: midcarpal instability II

CLINICAL: dislocation between the proximal and distal carpal rowsor any two bones (involving both rows) which normally form con-gruent joint surfaces

RADIOLOGIC: the loss of normal articular contact: a) between thearticular surfaces of the proximal and distal carpal rows (completemidcarpal dislocation); b) between scaphoid and trapeziotrape-zoidal articular surfaces (radial midcarpal dislocation); c) betweencapitolunate articular surfaces (central midcarpal dislocation); d) be-tween triquetrohamate articular surfaces (ulnar midcarpal disloca-tion); or e) any combination of a, b, c, or d. Arthrography will showno or inconsequential leaks between radiocarpal and midcarpaljoints through the scapholunate or lunotriquetral ligaments.

COMMENTS: 1) a true midcarpal dislocation that occurs with oneor more of the bones in the proximal carpal row dislocating from oneor more of the bones in the distal carpal row is very unusual. It ismuch more common to see other dislocations between bones of bothcarpal rows as a perilunate or a lunate dislocation or such a disloca-tion associated with fracture of the scaphoid and/or triquetrum.Other names are available for these conditions, such as perilunatedislocation, lunate dislocation, transscaphoid perilunate dislocation,etc. 2) Although not strictly correct, the term “midcarpal dislocation”has been used occasionally in past literature to refer to the conditionof lunate or perilunate dislocation where neither the lunate nor thecapitate is centered over the distal radius in the lateral neutral view ofthe wrist (see Figure 42).


REFERENCE:1. see MIDCARPAL SUBLUXATION

MIDCARPAL FRACTURE-DISLOCATION (SEE FIGURE 42)

SYNONYM: midcarpal instability III

CLINICAL: dislocation between the proximal and distal carpal rowsor any portion of those rows, associated with fracture(s) of the in-volved carpal bones (see MIDCARPAL DISLOCATION)

RADIOLOGIC: the loss of contact between the articular surfaces ofthe proximal and distal carpal rows: (a) between scaphoid and tra-peziotrapezoidal articular surfaces, (b) between capitolunate and tri-quetrohamate articular surfaces, or (c) a plus b associated with oneor more carpal fractures. The capitolunate dislocation can be mosteasily seen by observing the relationships of the radius, lunate, andcapitate on the lateral radiographic projection.

COMMENTS: 1) while this may not be an ideal term, it describes sit-uations in the perilunate-lunate fracture-dislocation spectrum inwhich the resting position of the carpus is transitional between therecognized lunate and perilunate dislocation classifications, and nei-ther the capitate nor lunate may be centered over the radius on lateralradiographic projection. 2) The strict definition of this term should

Fig. 42a

MIDCARPAL DISLOCATION (see text): a) PA radiograph shows that

there is a dislocation between the lunate, capitate, and triquetrum,

and the other carpal bones have moved with the capitate in a perilu-

nate type of pattern. b) The lateral radiograph shows that, in this

case, neither the capitate nor the lunate is centered over the distal

radius (dashed line through the center of the radius). (Reprinted with

permission from Gilula LA. Carpal injuries: analytic approach and

case exercises. AJR Am J Roentgenol. 1979;133:510. Fig 17.)

Fig. 42b



represent dislocation between all or most of the bones in the distalcarpal row from all or most of the bones in the proximal carpal rowswith additional carpal bone fractures; therefore, this would involvedislocation of the scaphotrapeziotrapezoidal (STT), capitolunate(CL), and triquetrohamate (TH) joints (see MIDCARPAL DISLO-CATION). This entity is very uncommon. The situation in comment#1 is much more common. 3) There is no perilunate type disruptionbetween the scaphoid and lunate, or lunate and triquetrum; there isinstability (in this instance a fracture-dislocation instability) be-tween the two carpal rows, with the distal carpal row malpositionedeither dorsal, palmar, radial, or ulnar to the proximal carpal row. 4)Some experts believe that the only midcarpal joint is the capitolunatejoint, while others believe that the STT and TH joints are also partof the midcarpal joint. 5) Involvement of the capitolunate, STT, tri-quetrohamate joints or any combination of these can be fracture-dislocations. 6) If there is an associated perilunate type disruption ofthe proximal carpal row (PCR), the condition becomes a carpal in-stability complex or combined (CIC), i.e., CIC with components ofthe injury being midcarpal instability (MCI) (either subluxation, dis-location, or fracture-dislocation). These components may be scapho-lunate dissociation (SLD) or lunotriquetral dissociation (LTD), orperilunate dissociation (PLD), if both SLD and triquetrolunate(lunotriquetral) dissociation (TLD) are present. 7) The opinions ofexperts who reviewed this term were divided equally as to whether itshould be discarded or retained.


REFERENCE:1. see MIDCARPAL SUBLUXATION

MIDCARPAL INSTABILITY (MCI) (FIGURE 43; SEE ALSO FIGURE 6)

SYNONYM: see comment #1; see MIDCARPAL SUBLUXATION; seeMIDCARPAL INSTABILITY TYPES I, II, and III

CLINICAL: midcarpal instability is a loss of normal alignment or re-lationship between bones in the proximal and distal carpal rows un-der physiologic loads, or under pathologic loads (trauma and othermechanical stress) due to ligamentous disruption or attenuation.

RADIOLOGIC: abnormal alignment between the proximal and distalcarpal rows as characterized by: 1) a capitolunate angle less than –30°or greater than +30° when the dorsal surfaces of the metacarpals andradius are parallel; or 2) abnormal displacement between the proxi-mal and distal carpal rows with applied stress producing the patient’spresenting symptoms.

COMMENTS: 1) examples of MCI include ulnar midcarpal instabil-ity, capitolunate instability pattern (CLIP wrist), carpal instabilitynondissociative (CIND), palmar and/or dorsal midcarpal instability,scaphotrapeziotrapezoidal (STT) instability (radial midcarpal), tri-quetrohamate instability, and midcarpal anteromedial instability(MAMI). 2) There is no general agreement if dissociation within theproximal and/or distal carpal rows can be present with MCI. 3) De-fining MCI points out the potential for instability at both the mid-carpal (MC) and radiocarpal (RC) levels. 4) This term should notinclude proximal carpal row malalignment due to distal radial mal-union, or the “adaptive carpus.” 5) Although a variety of lesions cancause this instability, a common link in MCI is a loss of normal con-tact joint forces at the midcarpal articulation, which ultimately leadsto an abnormal clunk. Ultimately, it is the flexion deformity of theproximal carpal row that unlinks the midcarpal joint and permits thesudden “clunk” as the proximal row extends when the wrist movesinto ulnar deviation. Definitive radiographic diagnosis of the “clunk”with dynamic examination can be made with video fluoroscopy orcineradiography. In other words, the normal smooth translation ofproximal row flexion to extension between radial and ulnar deviationoccurs only at the very last moment of ulnar deviation as the midcar-pal subluxation is reduced. Wrist arthrograms are commonly nor-mal. 6) Some persons believe that the underlying anatomy of MCI isan induced instability between the two carpal rows identified by thecapitate and the lunate due to palmar ligamentous stretching or dis-ruption (incomplete perilunate disruption). If it becomes fixed dor-sally, it is dorsal collapse; if fixed volarly, it is volar collapse. 7) MCImay be interpreted as the major category of abnormality, which in-cludes “midcarpal subluxation,” “midcarpal dislocation,” and “mid-carpal fracture/dislocation.” However, usual text reference to MCIrefers to the subluxation variety, which is reasonable, since disloca-tions and fracture-dislocations at this level can be designated specifi-cally as a midcarpal dislocation or fracture-dislocation. Nevertheless,the term “midcarpal instability” is more inclusive than the term“midcarpal subluxation.”


REFERENCES:1. see MIDCARPAL SUBLUXATION

2. Lichtman DM, Schneider JR, Swafford AR, Mack GR. Ulnar midcarpal instabil-ity: clinical and laboratory analysis. J Hand Surg [Am]. 1981;6:515-23.

Fig. 43

MIDCARPAL INSTABILITY (MCI): with dorsal displacing force, as with a

CLIP (capitolunate instability pattern) wrist maneuver, the capitate

subluxes out of the lunate fossa. This amount of displacement may

be seen in normal individuals with lax wrists or may be abnormal in

patients with associated symptoms.



3. Lichtman DM, Bruckner JD, Culp RW, Alexander CE. Palmar midcarpal instabil-ity: results of surgical reconstruction. J Hand Surg [Am]. 1993;18:307-15.

MIDCARPAL INSTABILITY (MCI) II see MIDCARPAL DISLOCATION

MIDCARPAL INSTABILITY (MCI) III see MIDCARPALFRACTURE-DISLOCATION

MIDCARPAL JOINT (MCJ) (FIGURE 44)

SYNONYMS: mediocarpal joint; any of the midcarpal joint segments,e.g., the capitolunate joint, the scaphotrapeziotrapezoidal joint, the tri-quetrohamate joint, and in some instances, the lunohamate joint

CLINICAL: the midcarpal or mediocarpal joint is the articulation be-tween all or any of the bones of the proximal and distal carpal rows.


COMMENTS: 1) some (erroneously) consider the capitolunate jointas the only joint in the middle of the carpus. This joint’s importanceis that it is the observational key to most radiologic decisions aboutthe presence or absence of subluxation or dislocation at this level. 2)

“Mediocarpal” is not used by some experts, as this term can be inter-preted to mean the ulnar (medial) aspect of the wrist. 3) Some be-lieve that the scapholunate and lunotriquetral joints are part of themidcarpal joint system, as are the carpometacarpal and intermetacar-pal joints of digits two through five.

CODE: Anatomic: Central (IIB)

REFERENCE:1. Zancolli EA, Cozzi EP. Atlas of surgical anatomy of the hand. New York: Churchill

Livingstone; 1992. p 416-31.

Fig. 44b

Fig. 44a

MIDCARPAL JOINT (MCJ): on all the following views, the white density

is the contrast (“dye”) that was injected under fluoroscopic control.

The thin space between the white contrast and each adjacent carpal

bone is the cartilage on that carpal bone. The contrast outlines the

midcarpal joint, which is the space between all the carpal bones

except for the pisotriquetral joint. This compartment commonly com-

municates (fills) with the second through fifth carpometacarpal

(CMC) joints. The first CMC joint normally does not communicate

with the midcarpal joint. a) PA view: contrast material in the midcar-

pal joint fills the second through fifth CMC joints, and some of this

contrast extends distally between metacarpal bases. Contrast out-

lines the distal surfaces of the scapholunate (arrow) and the lunotri-

quetral (small arrowhead) ligaments. b) Oblique view: this view

presents a different view of the midcarpal joint and is the best sur-

vey view to profile contrast in the trapeziotrapezoidal joint (arrow-

heads). c) Lateral view: the dorsal and ventral surfaces of the

midcarpal compartment are outlined. Some extravasation of contrast

out the needle track presents dorsal to the head of the capitate.

Fig. 44c



MIDCARPAL SUBLUXATION (MCS) (SEE FIGURE 6)

SYNONYM: midcarpal instability I (MC-I); see comment #4

CLINICAL: midcarpal subluxation is an abnormal condition inwhich the proximal and distal carpal rows are malaligned (incongru-ent) in relation to each other, but there is partial joint contact be-tween these carpal rows.

RADIOLOGIC: lateral view shows loss of parallelism or congruencybetween the articulating cortices of the capitate and lunate, but thecapitate head is not fully displaced out of the lunate fossa. For CIND-VISI or CIND-DISI collapse, a capitolunate angle in excess of 30° isusually considered abnormal and warrants further evaluation. SeeCOMMENTS. PA view: with carpometacarpal joints in profile (palmflat), capitolunate subluxation (or dislocation) is suspected when theproximal articular cortex of the head of the capitate overlies the cor-responding distal articular surface of the lunate. Scaphocapitate sub-luxation is suspected when this scaphocapitate joint is wider thanother intercarpal joints or when normally parallel surfaces of thesetwo carpal bones are overlapping.

COMMENTS: 1) Accurate radiologic descriptions of subluxations atthe scaphocapitate, scaphotrapeziotrapezoidal, and triquetrohamatejoints have not been clearly established in the lateral position. 2) Crite-ria for the radiologic diagnoses of midcarpal subluxations other thanthat described above are not generally known. 3) Midcarpal sub-luxation may be dorsal, volar, radial, or ulnar. 4) Some people believethat this is the mildest and stage 1 of “midcarpal instability” with stage2 being dislocation and stage 3 being fracture-dislocation. 5) There aresome midcarpal subluxations that do not have any appreciable DISI orVISI deformity, but simply present as translational deformities (asCLIP wrist). 6) Some people consider midcarpal subluxation synony-mous with midcarpal instability. Others disagree, feeling that sub-luxation can be very stable, whereas instabilities should be unstable.However, if the above radiologic definition is strictly applied, mid-carpal subluxation would apply only to the cases where the capitate issubluxed with respect to the lunate fossa. Midcarpal instability wouldapply to the other cases with abnormal alignment between carpal rowswithout capitolunate subluxation. Examples of this would includeCID-VISI, CIND-VISI, CID-DISI, and CIND-DISI, etc. Midcarpalinstability of the CIND-VISI or CIND-DISI type often produces a“catch-up clunk” as the proximal carpal row first delays then suddenlyadjusts from flexion to extension or vice versa on clinical or radiologicmotion studies. 7) Dorsal midcarpal instability, also known as CLIPwrist or capitolunate instability pattern, is one form of midcarpal sub-luxation, but so are CIND-VISI and CIND-DISI subluxations, whichconstitute the better known subluxations commonly referred to as“midcarpal instabilities.” 8) As is true with other carpal instabilities,these collapse deformities may be either static (present constantly) ordynamic (present only with provocative stress). 9) CLIP as well as theDISI and VISI deformities may have a radiocarpal translational defor-mity in association with the midcarpal level destabilization. Some ex-perts believe that it may be worthwhile to consider a “proximal rowinstability” and remember that the proximal row instability can comefrom damage on either or both sides of the proximal carpal row. 10) Asin other definitions with the term “instability,” some experts feelstrongly that “malalignments” are not the same as “instabilities” be-cause malalignments can be “stable” (see reference #8).


REFERENCES:1. see TRIQUETROHAMATE INSTABILITY

2. Gilula LA. Carpal injuries: analytic approach and case exercises. AJR Am J Roentgenol. 1979;133:503-17.

3. Louis DS, Hankin FM, Greene TL, Braunstein EM, White SJ. Central carpal in-stability: capitate-lunate instability pattern. Diagnosis by dynamic placement. Orthopedics. 1984;7:1693-6.

4. White SJ, Louis DS, Braunstein EM, Hankin FM, Greene TL. Capitate-lunate in-stability: recognition by manipulation under fluoroscopy. AJR Am J Roentgenol. 1984;143:361-4.

5. Johnson RP, Carrera GF. Chronic capitolunate instability. J Bone Joint Surg Am. 1986;68:1164-76.

6. Cooney WP, Garcia-Elias M, Dobyns JH, Linscheid RL. Anatomy and mechanics of carpal instability. Surg Rounds Orthop. 1989;3:15-24.

7. Cooney WP, Dobyns JH, Linscheid RL. Arthroscopy of the wrist: anatomy and classification of carpal instability. Arthroscopy. 1990;6:133-40.


NAVICULAR VIEW see SCAPHOID VIEW

NEUTRAL LATERAL VIEW (SEE FIGURE 35)

SYNONYMS: zero lateral position or view, neutral lateral position


RADIOLOGIC: a standard and reproducible radiographic viewachieved when the shoulder is abducted 90° such that the elbow is atthe level of the shoulder or the elbow is adducted against the trunk. Ineither of these positions, the elbow is flexed 90°, the forearm is in 0°pronation-supination, and the third metacarpal is parallel to the longaxis of the radius. With the elbow adducted against the trunk, a verti-cal x-ray beam enters radially and exits ulnarly. When the elbow is ab-ducted to the level of the shoulder, a horizontal x-ray beam entersradially and exits ulnarly. The x-ray cassette is against the ulnar side ofthe hand so that the x-ray beam enters the cassette at right angles.

COMMENTS: 1) an acceptable lateral position of the carpus can berecognized when the ventral surface of the pisiform projects midwaybetween the ventral surfaces of the capitate head and the distal poleof the scaphoid. This is called the SPC (scaphopisocapitate) align-ment criteria. See LATERAL VIEW (see Figure 35B). 2) Although it iscommonly described to have the elbow flexed 90° for this view, fail-ure to have 90° elbow flexion should not change the anatomic rela-tionship at the wrist, contrary to the situation with the NEUTRALPOSTEROANTERIOR VIEW of the wrist.


REFERENCES:1. Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saun-

ders; 1996. p 124-5.

2. Yang Z, Mann FA, Gilula LA, Haerr C, Larsen CF. Scaphopisocapitate alignment: criterion to establish a neutral lateral view of the wrist. Radiology. 1997;205:865-9.

NEUTRAL POSTEROANTERIOR (PA) VIEW (FIGURE 45)

SYNONYMS: zero posteroanterior position or view, neutral PA posi-tion, “preferred” PA position or view


RADIOLOGIC: a standard and reproducible radiographic viewachieved when the shoulder is abducted 90° such that the elbow is atthe level of the shoulder or the elbow is adducted against the trunk,the elbow is at 90° flexion, the forearm is in 0° pronation-supinationwith the palm flat on the radiographic cassette, and the third meta-carpal is parallel to the long axis of the radius. The x-ray beam passes



through the back of the carpus and exits the palm with the centralbeam centered at the head of the capitate. If the elbow is adductedagainst the trunk, the x-ray beam passes horizontally.

COMMENTS: 1) reproducible positioning promotes improved pre-cision for repeated assessments (measurements) and comparisons.2) The terms “PA” (posteroanterior) and “AP” (anteroposterior) areNOT synonymous. 3) Correct positioning as described here (see alsoPOSTEROANTERIOR VIEW) is necessary for accurate ulnar vari-ance measurements (see ULNAR VARIANCE). A practical point toremember is that the ulnar head moves distally in pronation, proxi-mally in supination.


REFERENCES:1. radiology textbooks

2. Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saun-ders; 1996. p 122-3.

NONDISSOCIATION (SEE FIGURES 15 AND 16)

SYNONYMS: linked, bonded, anatomically connected

CLINICAL: 1) opposite of dissociation; with respect to the wrist,

normal or near-normal linkage between the bones within the proxi-mal carpal row or between the bones within the distal carpal row. 2)Used with the term “carpal instability,” as in Carpal Instability Non-dissociative (CIND), to designate a malalignment in which there isnormal association of the skeletal elements within both the proximaland distal carpal rows, but a malalignment (incongruency) betweenthe two carpal rows. 3) Absence of dissociation (asynchronous move-ment) of the bones within a carpal row.

RADIOLOGIC: normal or near-normal motion patterns of the bonesof a carpal row, linked by interosseous ligaments, as observed by fluo-roscopy, videotape, cineradiography, or other imaging techniques

COMMENTS: 1) this term is usually used in conjunction with theterm “carpal instability.” 2) A small degree of ligament tearing orfracturing evidenced by arthrography, arthroscopy, or surgery doesnot negate this condition; only evidence of significant dissociativemovement between any two carpal bones within a carpal row willchange the diagnosis from nondissociation to dissociation. 3) Bothdissociative and nondissociative injuries may be present in the samewrist, and the term “carpal instability complex (combined) (CIC)” isdesigned to cover that situation. (See CIC.)


Fig. 45a

NEUTRAL POSTEROANTERIOR (PA) VIEW (see also Figure 2A): a) the palm of the wrist and hand is placed flat on the film cassette or x-ray table

without flexion, extension, or radial or ulnar deviation of the wrist. The third metacarpal is coaxial with the radius, the elbow is flexed 90°, and the

elbow is abducted to the shoulder height. b) The PA radiograph can be recognized to have been made in adequate position (elbow at shoulder

height) when the extensor carpi ulnaris groove (arrowheads) projects radial to the base (arrow) or the midportion of the ulnar styloid. The third

metacarpal and radius are coaxial. (Reprinted and modified with permission from Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadel-

phia: WB Saunders; 1996. p 122-3. Fig 5-29, A and B.)

Fig. 45b



REFERENCES:

1. see TRIQUETROHAMATE INSTABILITY and MIDCARPAL SUBLUXATION

2. Amadio PC. Carpal kinematics and instability: a clinical and anatomic primer. Clin Anat. 1991;4:1-12.

NORGAARD VIEW see BALL CATCHER’S VIEW

OS DISTALE see DISTAL CARPAL ROW

OS STYLOIDEUM see CARPAL BOSS

PALMAR see VOLAR

SYNONYMS: anterior, volar, ventral

CLINICAL: a term used in reference to certain portions (those nearthe palm of the hand) of the ventral or belly surface of the body, thewrist and hand


COMMENTS: 1) “volar” is used consistently as a synonym or even asthe preferred term in the hand literature. Both words are used inter-changeably in the hand literature, often in the same article. This isunlikely to change. 2) The reason “volar” remains a controversial an-atomic descriptor for the hand and wrist to some experts is becausesome people believed that the base word for this term, “vole,” refersto a short-tailed ratlike or mouselike rodent of the genus Microtus.Actually, the field mouse or “vole” is named from the Norwegian“woll” or field, not from the Latin “vol,” which refers to the palm orsole (James Dobyns). 3) Even though “volar” may not be the termpreferred by some anatomists, it is not likely that this term will be re-moved from hand and wrist literature.

CODE: Anatomic: Carpal (IID); Radiologic: Sides (IC)

REFERENCES:1. Webster’s Encyclopedic Unabridged Dictionary of the English Language. New

York: Portland House/Crown Publishers; 1989.

2. Warwick R, Williams PL, editors. Gray’s anatomy, 35th ed. Philadelphia: WB Saunders; 1973.

PALMAR CARPAL SUBLUXATION see PALMAR RADIOCARPAL SUBLUXATION

PALMAR CARPAL TRANSLATION see PALMAR RADIOCARPAL SUBLUXATION

PALMAR INTERCALATED SEGMENT INSTABILITY (PISI) seeVOLAR INTERCALATED SEGMENT INSTABILITY

PALMAR RADIOCARPAL SUBLUXATION (FIGURE 46)

SYNONYMS: volar carpal translation, palmar carpal subluxation,palmar carpal translation, palmar (or volar) radiocarpal translation

CLINICAL: this deformity has a reversed silver-fork deformity due tothe volar (palmar) displacement of the proximal carpal row, and maybe associated with CID or CIND, DISI or VISI, or ulnar translation.

RADIOLOGIC: the PA view shows an overlap of the subchondral scle-rotic line of the distal radius and the normally apposed articular sur-faces of the proximal carpal row. On the lateral view, the proximalcarpal row, as reflected by the lunate, demonstrates a loss of parallel-ism at the radiocarpal joint due to palmar displacement of the carpus.

COMMENTS: 1) this can be quantitated by using the RCA-capitatedistance (reference #1), which is the distance between the sagittal axisof the radius prolonged across the carpal space (radiocarpal axis or

RCA) and the sagittal axis of the capitate (RCA-capitate distance), ormore simply by noting the lunate to be at or volar to the volar third ofthe lunate sulcus of the radius. 2) Palmar radiocarpal subluxation isprobably most common in association with a fracture of the volar lipof the radius (the reverse Barton’s fracture-subluxation). However, afracture of the radius in association with the subluxation would notbe a true radiocarpal subluxation, but a radiocarpal fracture sublux-ation. 3) This is a very unstable condition (therefore could be calledan “instability”), often associated with global disruption of the radio-carpal support system and prone to redisplacement either palmar-ward or ulnarward or both. The volar Barton variant is actually morestable if reduced and healed, since the volar support ligaments areusually on the distal radius fragment.


REFERENCES:1. Wright TW, Dobyns JH, Linscheid RL, Macksoud W, Siegert J. Carpal instability

non-dissociative. J Hand Surg [Br]. 1994;19:763-73.

2. see SCAPHOLUNATE DISSOCIATION (SLD)

PARTIAL/INCOMPLETE DISLOCATION see SUBLUXATION

PARTIAL/INCOMPLETE LUXATION see SUBLUXATION

Fig. 46

PALMAR RADIOCARPAL SUBLUXATION: the carpus, as identified by the

proximal convexity of the lunate, is centered along the ventral portion of

the distal radius. The wrist has slight extension. A small chip fracture

(arrowhead) is off the ventral edge of the distal radius. Dorsal tilting of

the lunate is also present. (Reprinted with permission from Gilula LA,

editor. The Traumatized hand and wrist: radiographic and anatomic cor-

relation. Philadelphia: WB Saunders; 1992. p 324. Fig 13-7B.)



PARTIAL LIGAMENT TEAR see SPRAIN

PARTIAL PERILUNATE DISLOCATION see PERILUNATE SUBLUXATION

PERILUNAR DISLOCATION see PERILUNATE DISLOCATION

PERILUNATE DISLOCATION (PLD) (FIGURE 47)

SYNONYMS: perilunar dislocation, “lesser arc” disruption or dislo-cation, carpal instability combined-perilunar (CIC-PLD)

CLINICAL: a dislocation without fracture, in any direction, of someor all carpal bones around the lunate. This is commonly recognizedby dislocation between the capitate and lunate. The basic pattern maybe varied by retained connections between the lunate and other carpalbones or by partial/total realignment of the other carpal bones withthe radius, forcing the lunate into varying degrees of subluxation.

RADIOLOGIC: see CLINICAL. The fundamental criterion for a peri-lunate dislocation is description of a capitolunate dislocation withthe lunate maintaining all or much of its relationship with the radius.Historically, to be classified as a perilunate dislocation rather than alunate dislocation, the lunate should be more anatomically alignedwith the distal radius than the carpal bones surrounding the lunate.(See COMMENTS.)

COMMENTS: 1) “perilunate” and lunate injuries fit into the samecategory and mechanism. In both, the surrounding carpal bones aredislocated from the lunate; therefore, both could be called “perilu-nate dislocations.” A basic assumption for the above definition is thatin most cases, “lunate dislocation” is merely the final stage of a peri-lunate dislocation (see LUNATE DISLOCATION). 2) Since motion

or stress can often change the relationships between a lunate and peri-lunate type of displacement and since these patterns can easily mergeinto one another, it is not critical to do other than describe the rela-tionships between the forearm, lunate, and other carpal bones as theylie, including the occasionally seen displacement of the lunate intothe carpal canal, the palm, the forearm, or external to the skin. 3) Allor part of the radial or the ulnar columns may retain some con-nection with the lunate; in fact, the radial or ulnar columns may notbe truly dislocated in all instances in perilunate fracture dislocationor perilunate instability spectrum. 4) Some believe there are severalstages of perilunate instability, with the first being perilunate sublux-ation; second, perilunate dislocation; and third, perilunate fracture-dislocation. Lunate dislocation may be considered the fourth stage. 5)The perilunate spectrum classically begins with radial disruptionof the various fascicles of the radioscaphocapitate ligament, thenaround or through the scaphoid itself, and then across the carpus bya variety of possible pathways. That there is a similar perilunate-typedisruption that begins ulnarly and propagates radially has long beenknown clinically, and investigative work to clarify this mechanism isongoing.


REFERENCES:1. Dobyns JH, Linscheid RL. Fractures and dislocations of the wrist. In: Rock-



3. Viegas SF, Patterson RM, Peterson PD, Pogue DJ, Jenkins DK, Sweo TD, Ho-kanson JA. Ulnar-sided perilunate instability: an anatomic and biomechanic study. J Hand Surg [Am]. 1990;15:268-78.

Fig. 47a

PERILUNATE DISLOCATION (PLD):

a) on this PA view, the lunate is tri-

angular in shape, indicating some

tilting of the lunate, but the lunate

remains grossly parallel to the

radius. The distal articular surface

of the lunate overlaps the tri-

quetrum and capitate, indicating

dislocation between the lunate

and these two adjacent bones.

The proximal pole of the scaphoid

overlaps the radial styloid, indicat-

ing dislocation between these two

structures. Parallel articular sur-

faces between the scaphoid, tra-

pezium, trapezoid, capitate,

hamate, triquetrum, and metacar-

pals 1-5 indicate that these bones

are staying together as a unit. b)

On the lateral view, the lunate is

articulating with the radius but is

palmarly tilted. Dorsal dislocation of the capitate and the remainder of the carpal bones

is present, indicating a dorsal perilunate dislocation. (Reprinted and modified with per-

mission from Gilula LA, editor. The traumatized hand and wrist: radiographic and ana-

tomic correlation. Philadelphia: WB Saunders; 1992. p 290. Fig 12-2, A and B.) Fig. 47b



PERILUNATE FRACTURE-DISLOCATION (FIGURE 48)

SYNONYM: perilunar fracture-dislocation; see comment #6

CLINICAL: 1) dislocation of the carpal bones surrounding the lunateincluding single or multiple fractures of the carpal bones. 2) Loss ofarticular contact between the lunate and capitate with accompanyingbut variable degrees of subluxation or dislocation of the other carpaland radiocarpal articulations. (See PERILUNATE DISLOCATION).

RADIOLOGIC: 1) dislocation in any direction of the carpal bonessurrounding the lunate as evidenced by loss of articular contact be-tween the lunate and capitate accompanied by single or multiplefractures of the involved carpal bones. 2) Same as CLINICAL, withthe finding that the lunate maintains a more normal relationship tothe long axis of the radius than the remainder of the carpus, asindicated by the position of the capitate. 3) See PERILUNATEDISLOCATION for various stages of the perilunate displacementspectrum.

COMMENTS: 1) if the capitolunate joint is dislocated and the lunateis in anatomic or near-anatomic relationship to the distal radius, a“perilunate dislocation” is diagnosed regardless of the position of the

other carpal bones. 2) In the later phases of perilunate instability, therelationship of the lunate and capitate changes with respect to the ra-dius, so that neither the lunate nor capitate are normally aligned withthe radius (see MIDCARPAL DISLOCATION; COMMENTS), andthen finally the capitate may be more normally aligned with the ra-dius than the lunate. This latter condition would be lunate disloca-tion. 3) See PERILUNATE DISLOCATION. 4) Associated fracturesare within the “zone of vulnerability” that constitutes the “GreaterArc” of transosseous fractures with their associated dislocations, e.g.,transscaphoid, transcapitate dorsal perilunate fracture-dislocation.5) “de Quervain’s fracture-dislocation” is an older term and a syn-onym for the most common type of carpal fracture dislocation, thetransscaphoid perilunate fracture dislocation. 6) Perilunar injurywith fracture represents a combination arc injury, unless fractures ofthe scaphoid, capitate head or waist, with or without an avulsion ofthe radial side of the triquetrum are also present (see GREATER ARCINJURY).


REFERENCE:1. see PERILUNATE DISLOCATION

Fig. 48bFig. 48a

PERILUNATE FRACTURE-DISLOCATION: a) on this PA view, the lunate is triangular in shape, indicative of tilting. Articulation between the radius

and lunate is present, but parallelism consistent with normal articulation is absent at the lunotriquetral and scapholunate joints. The proximal

cortices of the capitate and hamate overlap the lunate. The scaphoid is fractured through its waist, and the proximal scaphoid fracture fragment

is rotated about 90° with the fractured surface of the proximal fracture fragment projecting into the scaphoid fossa. The distal portion of the

scaphoid, trapezium, capitate, hamate, triquetrum, and first through fifth metacarpals are articulating with each other normally, indicating that

they are staying together as a unit. b) Lateral view: the lunate is tilting ventrally while it is still centered over the palmar portion of the radius. The

capitate and other carpal bones have moved dorsally. The density with a convex surface distally (arrowheads), which is overlapping the lunate,

represents the rotated proximal scaphoid fracture fragment. These fea-

tures are those of transscaphoid, dorsal perilunate fracture-dislocation

with about 90° rotation of the proximal scaphoid fracture fragment.



PERILUNATE INJURY see COMBINATION ARC INJURY; GREATER ARC INJURY; LESSER ARC INJURY

PERILUNATE INSTABILITY (PLI)

SYNONYMS: perilunar instability, carpal instability complex-perilu-nate type (CIC-PLI), the de Quervain wrist injury spectrum

CLINICAL: 1) a generic term describing instability of the bone-ligament-bone complexes surrounding the lunate (i.e., scaphoid,capitate, triquetrum, and, occasionally, the hamate). The ultimatedegree of this instability spectrum involves increasing instability ofthe lunate itself. 2) A general term for the perilunate instability spec-trum of perilunate subluxation, perilunate dislocation, and perilu-nate fracture-dislocation.

RADIOLOGIC: see specifics for perilunate subluxation, dislocation,and fracture-dislocation

COMMENTS: 1) there is strong expert opinion that this term is anunprecise overview term that is not related to a specific problem,but a global “feeling.” Use of such a global term or overview can bemisleading and can allow authors to use such a term for conve-nience rather than provide a precise anatomic understanding of aproblem. 2) Several entities, as scapholunate and lunotriquetral dis-sociations, perilunate subluxations and dislocations, dissociative in-stabilities, and others, seem to fit into this category. 3) The majorvalue of this phrase may be in terms of injury patterns and patho-genesis. 4) Many people favor dropping this term; however, othersbelieve that it is very descriptive of the residua of the most commondislocations and gives a more immediate visualization of the poten-tial disruptions that may be present than any of the other terms, ei-ther alone or in combination. 5) This is considered by some to bethe generic term for perilunate instabilities with subclassificationsof subluxation, dislocation, and fracture-dislocation. 6) “Perilunateinstability” has the same generic coverage as do the terms “radiocar-pal” and “midcarpal” instability. As with those entities, the usualreference is to the specific injury, which will be one of the subcate-gories of subluxation, dislocation, or fracture dislocation, and oftenthe diagnostic term used will be specific of the subcategory, such as“scapholunate dissociation” (SLD). The recognized abnormality canbe either a specific discrete injury without other elements of the per-ilunate spectrum or may be a residua of a perilunate injury with theadditional ligament injury that the name implies. An example of thedifference this indicates is that SLD is a type of carpal instability dis-sociative (SLD-CID), while SLD as part of a perilunate instabilitywill be SLD-complex (SLD-CIC). Thus the overall instability of thecarpus will be greater for the SLD-CIC type of SLD, and this infor-mation is a factor in choosing treatment.


REFERENCE:1. see PERILUNATE SUBLUXATION, DISLOCATION, and FRACTURE-DISLOCATION

PERILUNATE SUBLUXATION (SEE FIGURES 6 AND 43)

SYNONYMS: perilunar subluxation, partial perilunate dislocation

CLINICAL: 1) a condition of the wrist that shows partial articularcontact between the lunate, the forearm bones, and the adjacent car-pal bones, usually recognized best by the radiologic alignment of theradiolunocapitate axis. 2) A condition in which joints in the lesserperilunate arc are in partial contact.

RADIOLOGIC: see CLINICAL. Partial contact remains between thearticular surfaces of the capitate head and the distal lunate con-

cavity, especially as seen on the lateral wrist view. The alignment ofthe lunate and the radius may also be incongruent but will not bedislocated.

COMMENTS: 1) this may be seen with one of the incomplete perilu-nate dislocations, e.g., as when the scaphoid is dislocated, the capito-lunate joint is subluxed, and the lunotriquetral and triquetrohamatejoints appear normal or nearly normal. 2) It is quite common for aperilunate dislocation to be incomplete or to spontaneously reduce tothe appearance of a DISI or VISI of the dissociative type. 3) The termis not used much because its component conditions, i.e., scapholunatedissociation (SLD) and lunotriquetral dissociation (LTD) are so wellknown under their specific names. However, when both are presenttogether, as is often the case following reduction of a perilunate dislo-cation, the term “perilunate subluxation” describes the condition verynicely. 4) May also apply to a residual midcarpal instability with eitheror both of SLD and TLD. 5) Any subluxation may be the residua of acomplete dislocation with the additional instability that this greaterdegree of initial injury implies. 6) Some experts are of the opinion thatit is impossible to define a true “perilunar subluxation.”


REFERENCE:1. see LUNATE DISLOCATION. Same as for the other perilunate instabilities.

PERMANENT CARPAL INSTABILITY see STATICCARPAL INSTABILITY

PISIFORM VIEW see SEMISUPINATED OBLIQUE VIEW

PISOTRIQUETRAL VIEW see SEMISUPINATED OBLIQUE VIEW

POSTERIOR (SEE FIGURE 45)

SYNONYMS: dorsal, back

CLINICAL: 1) closer to the back of the body or limb. 2) Displacementof a distal segment in that direction (see ULNAR: COMMENTS). 3)That portion of the wrist skeleton adjacent to the extensor tendonsand covered by the dorsal skin of the hand, wrist, and distal forearm.


COMMENTS: frequently used in combinations, as posterolateral orposteroanterior, particularly to describe a specific pathway


REFERENCE:1. anatomy or radiology textbooks or dictionary

POSTEROANTERIOR (PA) RADIAL DEVIATION VIEW (FIGURE 49)

SYNONYM: PA radial deviation projection

CLINICAL: NA

RADIOLOGIC: a radiographic view made from posterior (dorsal) toanterior (palmar) with the wrist in radial deviation and without flex-ion or extension. This view is usually performed as one of the films ofa motion study to determine carpal synchronicity, the amount of car-pal motion, and other intercarpal relationships in radial deviation.

COMMENTS: 1) this view can be readily compared to the same viewof the opposite wrist to help determine normal variations, such as thepresence and degree of ulnar translation, carpal impingement withthe radial styloid, distal ulnar instability, etc. 2) This is probably themost valuable view when combined with the PA ULNAR DEVIA-



TION VIEW, to recognize radial and ulnar motions at the midcarpaland radiocarpal levels. Such recognition of motion is readily accom-plished by looking at the edges of the capitate and lunate for midcar-pal motion and at the edges of the lunate and ulnar aspect of thelunate fossa of the radius for radiocarpal motion.


REFERENCES: 1. Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saun-

ders; 1996. p 131.

2. radiologic technology textbooks

POSTEROANTERIOR (PA) ULNAR DEVIATION VIEW (FIGURE 50)

SYNONYM: PA ulnar deviation projection

CLINICAL: NA

RADIOLOGIC: a radiographic view obtained with the pronatedhand and wrist in maximal ulnar deviation without extension at thecarpometacarpal joints and with the palm flat on the x-ray cassette.

Fig. 49a

POSTEROANTERIOR (PA) RADIAL DEVIATION VIEW: a) the palm is

placed flat on the tabletop or x-ray cassette with the wrist radially

deviated as much as possible without wrist extension. b) On this

PA radiograph with radial deviation, motion between the carpal

rows and between the radius and proximal carpal row can be seen

when compared to the neutral PA wrist view. (Reprinted with per-

mission from Gilula LA, Yin Y, editors. Imaging of the wrist and


Fig. 49b

Fig. 50b

Fig. 50a

POSTEROANTERIOR (PA) ULNAR DEVIATION VIEW: a) the palm is

placed flat on the tabletop or x-ray cassette with the wrist ulnarly

deviated as much as possible without wrist extension. b) On this PA

radiograph with ulnar deviation, motion between the carpal rows

and between the radius and proximal carpal row can be seen when

compared to the neutral PA wrist view. This view also elongates the

scaphoid so the waist of the scaphoid can be seen more easily than

on the routine PA neutral view. (Reprinted with permission from

Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia:

WB Saunders; 1996. p 126. Fig 5-31, A and B.)



The x-ray beam, centered at the capitate head, enters dorsally and ex-its palmarly.

COMMENTS: 1) this view may be positioned with elbow flexed 90°and held at shoulder height when ulnar variance positioning is of in-terest, and with the desire to standardize PA wrist techniques by radio-logic technologists. However, the elbow can be positioned at any heightif this view is only to survey the carpal bones, especially the scaphoidand its adjacent osseous relationships. 2) This view does elongate thescaphoid, but the scaphoid is still foreshortened (see SCAPHOIDVIEW). 3) As for the PA RADIAL DEVIATION VIEW, this view dis-plays intercarpal relationships in this ulnar-deviated PA position andcan be best compared to the opposite wrist for normal variations. 4)This is probably the most valuable view when combined with the PARADIAL DEVIATION VIEW, to recognize radial and ulnar motions atthe midcarpal and radiocarpal levels. Such recognition of motion isreadily accomplished by looking at the edges of the capitate and lunatefor midcarpal motion and at the edges of the lunate and ulnar aspect ofthe lunate fossa of the radius for radiocarpal motion.



ders; 1996. p 126.


POSTEROANTERIOR (PA) VIEW (SEE FIGURE 45)

SYNONYMS: posteroanterior projection/position, back-to-front pro-jection/position, dorsopalmar or dorsovolar projection/position


RADIOLOGIC: the x-ray beam enters the dorsum and exits the pal-mar aspect of the hand and wrist (see COMMENTS).

COMMENTS: 1) the recommended “zero” or “neutral” PA viewshould be performed in 0° pronation, 0° supination with the palm ofthe hand flat on the cassette, with elbow flexed 90° and elbow at shoul-der height to achieve standardization of technique. 2) “Pronated view”is not a true synonym of PA projection, since it is possible to obtain aPA view when the hand and wrist are not pronated, as when the handis supinated and the beam enters the dorsum of the wrist. 3) The PAview is still commonly performed when criteria in comment #1 arenot fulfilled.


REFERENCE:1. Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saun-

ders; 1996. p 122-3.

PROVOCATIVE MANEUVER (PM) (SEE FIGURE 6)

SYNONYM: stress test (active or passive)

CLINICAL: the application of passive, active, or combinations offorce to the wrist to elicit abnormal displacements, clunks, clicks,symptomatic “catches,” or pain that can be detected clinically and/orradiographically. The displacements may cause no symptoms, maycause symptoms unlike those of the complaint, or may reproduce thesymptoms of the complaint, with the last being most diagnostic of apositive test. Examples range from direct pressure to fist compressionto various scaphoid instability tests.


COMMENTS: 1) the resting stance of the carpal structures may besuggestive or diagnostic of a certain problem, but further confirma-

tion may come only with performing a provocative maneuver whilethe carpus is visualized radiographically. 2) Clinical and radiographicprovocative maneuvers (PMs) may be identical, but not always; forinstance, traction or fist compression may demonstrate very littleclinically but may be very instructive in showing specific bone dis-placements radiographically. 3) Passive force is mostly a passive rangeof motion, but it can include traction, compression, translation, cir-cumduction, and combinations of these. 4) Since there are numerousprovocative maneuvers, it is not possible to describe one or more ofthese in any more detail here. 5) Some experts believe that provoca-tive maneuvers test for abnormal movement, but a positive test doesnot necessarily identify a specific instability.

CODE: Tests (IV)

REFERENCE:1. Berger RA, Dobyns JH. Physical examination and provocative maneuvers of the

wrist. In: Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saunders; 1996. p 23-42.

PROXIMAL

SYNONYMS: cephalad, shoulderward

CLINICAL: 1) closer to or toward the root or base of the limb. 2)Further from the distal end of the limb.


COMMENTS: none



PROXIMAL CARPAL INSTABILITY see RADIOCARPAL INSTABILITY

PROXIMAL CARPAL ROW (PCR)

SYNONYM: the intercalated carpal row

CLINICAL: the scaphoid, lunate and triquetrum constitute the prox-imal carpal row (see comment #1 with respect to the pisiform).

RADIOLOGIC: NA

COMMENTS: 1) the true function of the pisiform is controversial. 2)Some authorities commonly include the pisiform in the description ofthe proximal carpal row (PCR), while others disagree. The pisiformmay also be considered as a palmar component of the PCR. Phyloge-netic arguments include the pisiform in the first carpal row. 3) Thepisiform is a bone that transfers forces indirectly from the flexor carpiulnaris tendon. Some people believe that since it has attachments to thetriquetrum, the pisiform is anatomically and functionally part of theproximal carpal row and could potentially (unproved) lend some sta-bility to the proximal carpal row. 4) Rarely, a bipartite scaphoid occurs.In that situation, the proximal pole of the scaphoid may function aspart of the PCR, and the distal pole, as part of the distal row; however,there is often a synchondrosis or synfibrosis between the fragmentssuch that the “bipartite” scaphoid may act as a single bone. 5) Theproximal carpal row, as defined, has a range of motion between itselfand the forearm structures proximally, the distal carpal structures dis-tally, and also internally between the components of the PCR.


REFERENCES: 1. Taleisnik J. The wrist. New York: Churchill Livingstone; 1985.2. May O. [The pisiform bone: sesamoid or carpal bone]. Ann Chir Main Memb

Super. 1996;15:265-71. French.



PROXIMAL WRIST JOINT see RADIOCARPAL JOINT

RADIAL

SYNONYMS: lateral; thenar; thumbside; thumbward; outer, of theradius; radiolateral

CLINICAL: 1) toward the radius or the radial column of the osseousstructures (radial styloid, scaphoid, trapezium, first metacarpal) ofthe wrist. 2) See LATERAL.


COMMENTS: 1) unfortunately, this word is used both as a direction(toward the radius or the portion of the forearm occupied by the ra-dius) AND as possessive or descriptive, i.e., radial styloid, radial tu-berosity, radial osteotomy, etc. As a direction, it is used along with thewords in the synonym to mean “away from the ulna or medial aspectof the forearm.” Used as a possessive or descriptive term, it can (andin some experts’ opinion should) be replaced by the phrase “of theradius.” 2) Although “radial” is always an adjective and is never anoun, it is often used in place of “radius’s” or “of the radius.” 3) Theterm “lateral” should be avoided whenever the meaning of “radial” isbeing used to minimize the chance of misusing the word “lateral.” 4)“Radial” is not only used as “toward the radius” but also as “towardthe radial column of the osseous structures (radial styloid, scaphoid,trapezium, first metacarpal) of the wrist.”

CODE: Anatomic: Radial (IIA); Radiologic: Sides (IC)


RADIAL COLUMN OF THE CARPUS (SEE FIGURE 21)

SYNONYM: lateral carpal column

CLINICAL: the combination of the scaphoid fossa of the radius, ra-dial styloid, scaphoid, trapezium, and trapezoid, and all the interven-ing articulations


COMMENTS: 1) some experts disagree with the column concept.Others would accept this as a descriptive, historic term that does notimply a kinematic function. 2) This term refers only to the carpus.


REFERENCE:1. Ruby LK. Fractures and dislocations of the carpus. In: Browner BD, Jupiter JB,

Levine AM, Trafton PG, editors. Skeletal trauma. Philadelphia: WB Saunders; 1992. p 1025-62.

RADIAL INCLINATION ANGLE see RADIAL INCLINATION OF DISTAL RADIUS

RADIAL INCLINATION OF DISTAL RADIUS (FIGURE 51)

SYNONYMS: ulnar inclination of the distal radius, radioulnar incli-nation, radial-ulnar inclination, slope, lateromedial inclination, ra-dial inclination angle

CLINICAL: radial inclination of the distal radius is an angle mea-sured on a PA radiograph formed by the intersection of a line fromthe distal ulnar aspect of the radius to the tip of the radial styloid witha line perpendicular to the long axis of the radius.

RADIOLOGIC: the long axis of the radius is obtained by bisecting itscanal on the neutral PA view at 2-3 cm and 4-5 cm (or 4 and 8 cm)proximal to the distal articular surface of the radius and joining thepoints with a line that extends distally into the carpus. The distal tipof the radial styloid and the ulnar aspect of the distal radial articularsurface are joined by a second line. A perpendicular from the longaxis of the radius is placed to intersect the second line. The angle be-tween these two lines is radial inclination. The mean as in reference#2 below is 22 ± 3°; however, various authors (reference #1) show arange from 12.9-35°.

COMMENTS: 1) there may be two angles of inclination, dependingon whether the tracing is performed along the dorsal or the ventral(volar) rims of the radius. Although unproven, it is believed thatgenerally the ulnar aspect of the lunate fossa (usually projecting asthe ventral rim) is used as the ulnar point for measurement. 2) Someexperts prefer many of the above synonyms combined with thephrase “of the distal radius” for clarity, as slope and inclination ofthe distal radius can be evaluated on the lateral radiograph or view ofthe distal radius. 3) The distal rim of the radius forms an angle ofabout 23° to the long axis of the forearm. In manual prehension, thewrist deviates ulnarly about the same extent, i.e., 20-25°, to accom-modate objects between the thumb and fingers. This results in the

Fig. 51

RADIAL INCLINATION OF DISTAL RADIUS: a) method of DiBenedetto et al.: A

and B are two points bisecting the distal radius 4 and 8 cm proximal to the

radiocarpal joint to make the line X. The line Y is drawn through point C, which

is the distal sigmoid notch, and D, which is the tip of the radial styloid. Z is a

line drawn perpendicular to line X through point C. Radial inclination angle is

the angle between lines Z and Y. E is a point on line Z to allow radial height to

be measured between D and E. Radial inclination angle is 22° + 3°. b)

Method of Matashita, Firrel, and Tsai. This method is a modification of that of

DiBenedetto et al., in which the central axis (X) of the ulna is drawn through

midpoints A and B at 2 cm and 4-5 cm proximal to the distal end of the ulna.

(Reprinted with permission from Gilula LA, Yin Y, editors. Imaging of the wrist

and hand. Philadelphia: WB Saunders; 1996. p 231. Fig 9-5, A and B.)



carpus transmitting loads at approximately 90° to the inclination ofthe distal radius.

CODE: Anatomic: Measurements (IE)

REFERENCES: 1. Baratz ME, Larsen CF. Wrist and hand measurements and classification

schemes. In: Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadel-phia: WB Saunders; 1996. p 225-59.

2. DiBenedetto MR, Lubbers LM, Ruff ME, Nappi JF, Coleman CR. Quantification of error in measurement of radial inclination angle and radial-carpal distance. J Hand Surg [Am]. 1991;16:399-400.

3. Matsushita K, Firrell JC, Tsai T-M. X-ray evaluation of radial shortening for Kien-böck’s disease. J Hand Surg [Am]. 1992;17:450-5.

RADIAL MIDCARPAL JOINT see TRISCAPHE JOINT

RADIAL OBLIQUE SCAPHOID VIEW see SEMIPRONATED OBLIQUE VIEW

RADIOCARPAL INSTABILITY (RCI) (SEE FIGURE 64)

SYNONYM: proximal carpal instability

CLINICAL: dyssynchronous motion or malalignment between theradius and part of or all of the proximal carpal row. This includes allactual instabilities at the radiocarpal level other than adaptive posi-tionings, as the carpus adapting to distal radius deformity from animpacted distal radius fracture. (See COMMENT.)

RADIOLOGIC: dynamic instabilities are best shown on fluoroscopy,which includes standard and stressed range of motion views of bothwrists. For static radiocarpal malalignment, ulnar (infrequently ra-dial) translation is best appreciated on the PA view, and dorsal andventral translation are best shown on the lateral or sagittal views. (SeeCLINICAL.)

COMMENTS: 1) radiocarpal instability may present as a CIND in-stability (Ulnar Translation, Type I) or may include a CID instability(Ulnar Translation, Type II). In the latter case, there will be both ex-trinsic and intrinsic ligament damage, qualifying the lesion as a CIC(Carpal Instability Complex/Combined) lesion. 2) RCI is due to liga-ment damage to the support structures between the forearm and theproximal carpal row and can apply to any of the usual triad of sub-luxation, dislocation, or fracture-dislocation, the more commonmembers of the latter group being the Barton’s, the reverse Barton’s,and the Chauffer’s injuries. For subluxations, the proximal carpalrow is displaced, ulnar > dorsal > volar > radial. The same order offrequency is true of dislocations except that the displacement isgreater. Subluxations may present only dynamically as dyssynchro-nous motion or loss of normal alignment or may be statically mala-ligned, a common presentation for ulnar translation. 3) With ulnardisplacement, a dimple may appear on the radial side of the wrist.The carpus may be subluxed palmarly as well as ulnarly. 4) The term“instability” is again brought into question here by some experts. Ul-nar translocation, a type of radiocarpal instability, is really an ulnarshift (slide) of the proximal carpal row seen commonly in rheuma-toid arthritis, and most of these deformities are fixed. “Instability”implies to some experts that the carpus can be put back into its nor-mal anatomic position. Since most in these cases cannot be placedback to anatomic position, these experts believe that the “instability”part of the term is not strictly correct, unless this malalignment oc-curs only with stress and reduces when stress is released (see PRO-VOCATIVE MANEUVER). 5) Another clinical entity not yet welldescribed is believed to exist by some experts; that is the so-called ro-

tational instability at the radiocarpal joint level. This is a supinationdeformity. It is not yet clear what mechanism causes this deformity(see reference #2). 6) Radiocarpal instability may be best related toradiocarpal translation mainly without any lunate tilting.



2. Ritt MJ, Stuart PR, Berglund LJ, Linscheid RL, Cooney WP 3rd, An KN. Rota-tional stability of the carpus relative to the forearm. J Hand Surg [Am]. 1995;20:305-11.

RADIOCARPAL JOINT (FIGURE 52)

SYNONYMS: proximal joint of the wrist or of the carpus, proximalwrist joint, radioulnocarpal joint

CLINICAL: a joint between the radius and the proximal carpal bones

Fig. 52a

RADIOCARPAL JOINT: on all the following views, the white density is the

contrast (“dye”) that was injected under fluoroscopic control. The thin

space between the white contrast and the underlying radius is the car-

tilage on the surface of the radius, and the thin darker space between

the contrast and the adjacent carpal bone is the cartilage on that car-

pal bone. Contrast outlines the radiocarpal space, the space between

the radius, carpal bones of the proximal carpal row, and the triangular

fibrocartilage. Commonly, the pisotriquetral joint communicates to the

radiocarpal joint. a) PA view: contrast material in the radiocarpal joint

fills the pisotriquetral joint (large arrowhead), which extends into the

prestyloid recess (white straight arrow). Portions of the radioscapho-

capitate ligament (small arrowheads) and the long radiolunate or radi-

olunotriquetral ligament (black arrows) are outlined. A small preradial

recess (curved arrow) is present. b) Oblique view: the prestyloid recess

(white arrow) projects separately from the proximal recess of the pisot-

riquetral joint (large arrowheads). Portions of the radioscaphocapitate

(small arrowheads) and the radiolunotriquetral or long radiolunate liga-

ment (black arrows) are evident. c) Lateral view: ventrally is a small

preradial recess (curved arrow) and a larger dorsal scaphoid recess

(arrowheads). Some extravasation of contrast out the needle track is

present dorsally (arrow).



being composed of the radioscaphoid and radiolunate joints (seeCOMMENTS)

RADIOLOGIC: arthrographically, the entire space between the fore-arm and the proximal carpal row with extensions into the pisotrique-tral joint and the recessus sacciformis is usually found to be oneanatomic space (see CLINICAL and COMMENTS).

COMMENTS: 1) although the term refers to the entire joint systembetween the forearm and the proximal carpal row, it is sometimesused to refer only to the portion of the joint that involves the radiusand the adjacent carpals (scaphoid and one-half the lunate). In thislatter instance, the other portion of the proximal wrist joint is re-ferred to as the ulnocarpal joint, although it is more accurately theTFC (triangular fibrocartilage) carpal joint. 2) Anatomically, the ra-diocarpal joint is actually the radioulnocarpal joint, usually with ex-tension to the pisotriquetral joint and to the recessus sacciformis. It is

possible to subdivide the joint into its various constituents as the ra-dioscaphoid joint, the radiolunate joint, the TFC-lunate joint, andthe TFC-triquetral joint, although the last two are often called theulnocarpal joint. 3) This joint system accounts for roughly half ofcarpal area motion and is commonly involved in both trauma anddisease. Many treatments for carpal problems involve this joint andits osseous boundaries.


REFERENCES:1. see CARPAL INSTABILITY COMBINED (CIC)

2. anatomy or radiology textbooks

RADIOLUNATE DISLOCATION see LUNATE DISLOCATION

RADIOSCAPHOID SUBLUXATION see SCAPHOID SUBLUXATION;ROTARY SUBLUXATION OF THE SCAPHOID

RADIOULNAR ABUTMENT SYNDROME see IMPINGEMENT,RADIOULNAR

RADIOULNAR COMPRESSION SYNDROME see IMPINGEMENT,RADIOULNAR (DISTAL)

RADIOULNAR INCLINATION see RADIAL INCLINATION OFTHE DISTAL RADIUS

RADIOULNOCARPAL JOINT see RADIOCARPAL JOINT

RADIUS PORTION OF THE DISTAL RADIOULNAR JOINT seeSIGMOID SULCUS OF THE DISTAL RADIUS

REAGAN-LINSCHEID TEST see TRIQUETROLUNATE(or LUNOTRIQUETRAL) BALLOTTEMENT

REVERSE PA OBLIQUE VIEW (FIGURE 53)

SYNONYMS: ulnar oblique scaphoid view/position, reverse PA ob-lique position, ulnar-deviated overpronated scaphoid view

CLINICAL: NA (see COMMENTS)

RADIOLOGIC: the wrist is rotated 45°, so that the thumb side isclosest to the film cassette and the ulnar side of the wrist is off thecassette. The fingers may be flexed sufficiently to support the hand aslong as the metacarpals remain collinear with the distal radius. Thecentral ray is directed perpendicular to the cassette through the mid-portion of the scaphoid. Ulnar deviation of the wrist may be used toelongate the scaphoid more, or the wrist may be positioned straightwithout ulnar deviation.

COMMENTS: 1) this view is designed to look at the dorsoradial partof the scaphoid waist especially to detect avulsion fractures off thedorsoradial aspect of the waist of the scaphoid as well as to project thepisiform off the triquetrum. 2) Supplemental projections with vari-ous degrees of ulnar deviation of the wrist or various degrees of thisreverse oblique position can also be performed. 3) Alternate views ofthe scaphoid and other portions of the proximal carpal row are some-times needed to diagnose or evaluate injury.


REFERENCE:1. Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saun-

ders; 1996. p 142.

Fig. 52c

Fig. 52b



RING DISRUPTION see TRANSVERSE INSTABILITY PATTERN

ROTARY COLUMN (SEE FIGURE 21)

SYNONYMS: medial column, triquetrum, ulnar column

CLINICAL: 1) the hamate, triquetrum, and triangular fibrocartilageand their articulations. 2) See ULNAR COLUMN. 3) The triquetrumis considered the rotary or medial column (in Navarro’s and Taleis-nik’s “longitudinal columnar concept” of the wrist) because of its ro-tation from volar flexion to dorsiflexion as the wrist is moved fromradial to ulnar deviation.


COMMENTS: 1) the cause of this rotation of the triquetrum is thereaction force created by movement at the helicoid articulating sur-faces of the triquetrohamate joint. Some people believe that rotarycolumn (medial column) instability is therefore synonymous withlunotriquetral instability. However, in recent years it has become ap-parent that instability patterns are not longitudinal, and the colum-nar theory has given way in some degree to the concept of “transversecarpal instabilities.” 2) Most experts do not use the term “rotary col-umn.” This term is more of historical than current value. 3) Thisterm simply indicates the ulnar side of the wrist. Some experts referto an ulnar carpal column and keep that limited to the triquetrum,while others refer to the ulnar aspect of the wrist, which may includethe distal ulna, the triangular fibrocartilage, the ulnar side of the car-pus, and the fourth and fifth metacarpal bases. 4) Although disrup-tion patterns are seldom longitudinal (columnar) except for the axialpatterns of fracture and fracture-dislocations, force transmission iscommonly longitudinal. 5) This is the column containing the axis ofpronosupination.


REFERENCE:1. see LONGITUDINAL (COLUMNAR) INSTABILITY PATTERN

ROTARY (ROTATORY) SUBLUXATION OF THE SCAPHOID (RSS)(FIGURE 54) see SCAPHOID SUBLUXATION/DISLOCATION

SYNONYM: scaphoid subluxation, scaphoid instability, see com-ment #1

CLINICAL: a pathologic displacement (usually a hyperflexion defor-mity with pronation and/or palmar rotation) of the scaphoid with orwithout obvious scapholunate disruption secondary to disruption ofsome or all of the ligamentous attachments of the scaphoid (seeRADIOLOGIC)

RADIOLOGIC: 1) radiographic features include: (a) scapholunate(SL) widening in the midportion of the SL joint greater than twicethe width of a normal capitolunate joint; (b) foreshortening of thescaphoid (signet ring sign on the PA projection) when the wrist is inneutral position (the long axis of the third metacarpal shaft is parallelto the long axis of the radius); (c) increased radioscaphoid angle(>60°) on lateral projection (this assumes that a 45° radioscaphoidangle is normal, and a 90° radioscaphoid angle is when the scaphoidis at right angles to the radius); (d) subluxation of the scaphoid ontothe dorsal rim of the radius on lateral projection; (e) increasedscapholunate angle of more than 60-80° with the radiolunate anglenormal on the lateral view; and (f) decreased “cortical ring distance”(distance from the “ring” in the waist of the scaphoid to the proximalscaphoid cortex with the hand in the neutral PA position) to less than7 mm or 4 mm shorter than the normal (contralateral) wrist (see ref-erence #5). 2) As in other carpal instabilities, “static” and “dynamic”

Fig. 53a

REVERSE PA OBLIQUE VIEW: a) the wrist is placed in ulnar deviation to align

the radial side of the thumb with the radial side of the forearm. Flexing the fin-

gers into a fist or placing the ulnar side of the hand on a 45° sponge will serve

to overpronate the wrist. b) A PA radiograph with the wrist in this position pro-

files the dorsoradial surface of the scaphoid and the ventroulnar surface of

the triquetrum. This also profiles the pisiform off the carpus and provides a

different surface view of the remainder of the carpus. (Reprinted with permis-

sion from Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia:


Fig. 53b



subgroups are recognized: (a) “static,” when visible on a PA or lateralradiograph of the wrist; and (b) “dynamic,” when rotary subluxationcan be demonstrated by any other radiographic views, stress loading,cineradiography, fluoroscopy, arthrography, or other ancillary stud-ies (tomography, MRI, etc.).

COMMENTS: 1) controversy exists concerning SLD (scapholunatedissociation) and RSS. At least one expert states that SLD may or maynot be present with rotary subluxation of the scaphoid; therefore,RSS and scapholunate dissociation are not truly synonyms. Whentrue scapholunate diastasis is present, RSS should also be present.However, other experts believe that at this time it is not clear ifscapholunate diastasis (SLD) and RSS are synonymous, or if one is asubset of the other. However, many experts believe that RSS and SLDrefer to the same condition. 2) Commonly, the proximal pole of thescaphoid moves dorsally and rotates onto the dorsum of the radiusand capitate to produce rotary subluxation of the scaphoid. However,the scaphoid can displace in many ways as yet poorly defined, sec-ondary to various forms of periscaphoid ligamentous rupture, someresulting in overload and degenerative arthritis of the scaphotrapezi-otrapezoidal joint instead of the radioscaphoid joint. 3) Some expertsbelieve that rotary displacement of the scaphoid refers only to its in-creased flexion in the sagittal plane and that angulation in the radi-oulnar plane or pronation/supination rotation in the axial plane isnot considered. Other experts disagree and believe RSS exists whenthe scaphoid moves abnormally in any direction. 4) Some experts

support the concept of “predynamic” rotary subluxation of thescaphoid, when rotary subluxation is not demonstrable by any study,but the clinical diagnosis is unequivocal. This “predynamic” conceptis very controversial among experts. 5) SLD is usually part of thescapholunate advanced collapse (SLAC) wrist. 6) There may or maynot be associated instability of the rest of the carpus. 7) SeeSCAPHOLUNATE DISSOCIATION (SLD) for further discussion ofthe relationship between RSS and SLD (scapholunate dissociation).


REFERENCES:1. Watson HK, Hempton RF. Limited wrist arthrodeses. I. The triscaphoid joint. J

Hand Surg. 1980;5:320-7.

2. Watson HK, Ashmead D 4th, Makhlouf MV. Examination of the scaphoid. J Hand Surg [Am]. 1988;13:657-60.

3. Watson HK, Ryu J, Akelman E. Limited triscaphoid intercarpal arthrodesis for rotatory subluxation of the scaphoid. J Bone Joint Surg Am. 1986;68:345-9.

4. Watson HK, Ottani L, Pitts EC, Handal AG. Rotary subluxation of the scaphoid: a spectrum of instability. J Hand Surg [Br]. 1993;18:62-4.

5. Armstrong GW. Rotational subluxation of the scaphoid. Can J Surg. 1968;11:306-14.

6. see SCAPHOLUNATE DISSOCIATION (SLD) for references to other management methods

ROW INSTABILITY see TRANSVERSE INSTABILITY PATTERN

SAGITTAL PLANE (SEE FIGURE 36)

SYNONYMS: lateral plane, longitudinal axis or plane (see comment#2 in LONGITUDINAL AXIS), sagittal axis

CLINICAL: with the hand(s) in anatomic position (parallel to the trunkwith the forearm and hand in supination), this is a plane parallel to thesagittal suture of the skull. In cross-sectional imaging, sagittal plane is

Fig. 54b

Fig. 54a

ROTARY (ROTATORY) SUBLUXATION OF THE SCAPHOID (RSS): a) on this

PA view, the scaphoid is foreshortened, that is, the scaphoid is shorter

in its proximal-distal length, creating a “signet ring” (arrowheads)

appearance due to the distal scaphoid pole being projected end-on

overlapping the waist of the scaphoid. The “cortical ring distance”

between the edge of this “ring” and the proximal edge of the scaphoid

is decreased (see text). The scapholunate joint is widened when com-

pared to the width of the normal-appearing capitolunate joint. b) The

lateral view shows the scaphoid to be tilted palmarly, with the lunate

in neutral position (not tilted) to produce a scapholunate angle of

about 80°. These findings are supportive of rotary subluxation of the

scaphoid. (Reprinted with permission from Gilula LA, editor. The

traumatized hand and wrist: radiographic and anatomic correlation.




used as a synonym for a section made along the anteroposterior planeproducing a “lateral” cross-sectional view of the hand.

RADIOLOGIC: used as a synonym for a section made along the an-teroposterior plane parallel to the sagittal suture and producing aview called a “lateral”

COMMENTS: none



SAGITTAL VIEW see LATERAL VIEW

SCAPHOID INSTABILITY see ROTARY SUBLUXATIONOF THE SCAPHOID

SCAPHOID NONUNION ADVANCED COLLAPSE (SNAC) seecomment #9 in SCAPHOLUNATE ADVANCED COLLAPSE (SLAC)

SCAPHOID PROJECTION see SCAPHOID VIEW

SCAPHOID PROVOCATIVE MANEUVER see SCAPHOIDSTRESS TEST

SCAPHOID SHIFT TEST see SCAPHOID STRESS TEST

SCAPHOID SLIDER-CRANK MECHANISM seeSLIDER-CRANK MECHANISM

SCAPHOID STRESS TEST (WATSON) (FIGURE 55)

SYNONYMS: scaphoid provocative maneuver, Watson maneuver,Watson test, scaphoid subluxation test, scaphoid shift test

CLINICAL: a provocative clinical maneuver of the scaphoid per-formed by an examiner to determine the degree and type of mobilityand symptom level during displacement of the scaphoid. The test isperformed by stabilizing the distal radius with one hand and placingpressure on the palmar aspect of the distal scaphoid tuberosity with

the other hand while the wrist is brought from a position of ulnarto radial deviation to prevent the excessive flexion of the unstablescaphoid. A positive test elicits pain of presenting type (see comment#6), abnormal mobility, and a palpable or audible clunk prior to dis-placement of the scaphoid from the scaphoid fossa of the radius.

RADIOLOGIC: when this maneuver is performed under fluoro-scopic control, abnormal displacement of the proximal pole of thescaphoid out of the scaphoid fossa of the distal radius can be ob-served, especially in the lateral or slightly supinated lateral position.Such motion when accompanied with pain of the presenting typeconstitutes a positive test. Increased motion can be recognized bycomparing the amount of scaphoid displacement with the asymp-tomatic wrist.

COMMENTS: 1) this movement of the proximal scaphoid pole maytake place without fluoroscopically obvious scapholunate diastasis. 2)Without fluoroscopic or cineradiographic control, sometimes it maybe impossible to tell if pain or popping signifies abnormal motion atthe radiocarpal or midcarpal joint level, scaphocapitate instability, orinstability at the proximal or distal poles of the scaphoid. 3) The testmay be positive bilaterally and may be positive in an asymptomaticwrist, since mild to moderate scaphoid instability can be a variant ofnormal (hypermobile scaphoid) or abnormal but functionally com-petent. 4) Several similar tests give similar findings. These tests in-clude direct pressure dorsally over the proximal end of the scaphoidor ventrally under the distal tuberosity of the scaphoid, or both, andexerting pressure for ballottment of the unstable scaphoid up anddown. When unstable enough, the scaphoid will do its own snap-ping, creaking, and hurting with active deviation motion or circum-duction motion. When pressure is applied in the areas described,evoked tenderness is also a significant positive finding. 5) One studyevaluating this test found a low sensitivity and specificity for this test(see reference #2). 6) This test might be positive in the presence ofpathologic cartilage at the proximal pole of the scaphoid without anyevidence of ligament rupture. Conclusions given by this test must becautious, since pain just defines pain, nothing else.

CODE: Tests (IV)

Fig. 55a

SCAPHOID STRESS TEST (WATSON): constant pressure is placed against the distal pole of the scaphoid as the patient’s wrist is brought from ulnar devi-

ation (a) to radial deviation (b), attempting to sublux the proximal pole of the scaphoid out of the scaphoid fossa of the radius. (Reprinted with permis-

sion from Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saunders; 1996. p 197. Fig 7-26, A and B.)

Fig. 55b



REFERENCES: 1. Watson HK, Ashmead D 4th, Makhlouf MV. Examination of the scaphoid. J

Hand Surg [Am]. 1988;13:657-60.

2. LaStayo P, Howell J. Clinical provocative tests used in evaluating wrist pain: a descriptive study. Hand Ther. 1995;8:10-7.

SCAPHOID SUBLUXATION/DISLOCATION (SEE FIGURE 54)

SYNONYMS: radioscaphoid subluxation/dislocation, rotary (rota-tory) subluxation of the scaphoid (see COMMENTS)

CLINICAL: subluxation is an abnormal condition in which thescaphoid is malaligned with one or more of its adjacent bones, butpartial joint contact is maintained. Dislocation at a scaphoid joint ex-ists when all joint contact is lost between the scaphoid and an articu-lating bone(s) at that joint.

RADIOLOGIC: in the neutral PA projection, subluxation of thescaphoid at the radioscaphoid joint is inferred by the presence ofscapholunate diastasis (scapholunate joint width at its midportion isat least twice as wide as the normal capitolunate joint) without evi-dence of Type II ulnar translocation. Alternatively, when the wrist isin a neutral position (third metacarpal and radius in a straight line)there may be an associated “cortical ring” sign (with palmar flexionof the scaphoid, the cortices of the distal scaphoid pole are projectedas a circle over the mid body of the foreshortened scaphoid). Theforeshortened scaphoid is evidenced by a decrease in the minimaldistance between the “ring” and the proximal pole of the scaphoid toless than 7 mm, or 4 mm shorter than the normal contralateral wrist(reference #1). Either or both of these findings may be present. In theneutral lateral projection the radioscaphoid congruence may be lost,typically with dorsal displacement of the proximal scaphoid pole.The radioscaphoid angle as measured between the long axis of the ra-dius and the tangential long axis of the scaphoid is greater than 75°(see reference #2). Loss of parallelism between the tangential longaxis of the scaphoid and the volar flare of the distal radius (lines con-verge to an acute angle) may be a useful clinical sign.

COMMENTS: 1) the prior description refers to subluxation/disloca-tion changes at the proximal pole of the scaphoid. Subluxation param-eters for the distal scaphoid and its relationships to the capitate,trapezium, and trapezoid are not as well defined but in general are a re-ciprocal of the proximal pole malalignment. Full dislocation at eitheror both poles does occur, sometimes with considerable displacementof the scaphoid or of its fragments. 2) At the distal end of the scaphoid,dorsal subluxation of the trapezium is considered scaphotrapezial sub-luxation. 3) Unusually, scaphoid subluxation may occur without ro-tation. 4) Except for dynamic and provocative types, there is nodifference between scaphoid subluxation and rotary subluxation of thescaphoid or scapholunate dissociation. Therefore, in some situations,all three of these may be synonymous. 5) Although dorsal subluxationis most common, it is also possible to have ulnar, radial, or volar sub-luxation of the scaphoid. 6) This is distinct from but is frequently asso-ciated with DISI. 7) Complete dislocations of the scaphoid are rarities.


REFERENCES:1. Armstrong GW. Rotational subluxation of the scaphoid. Can J Surg. 1968;

11:306-14.

2. Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saun-ders; 1996. p 239.

3. Destot EAJ. Injuries of the wrist: a radiological study (translated by FRB Atkin-son). London: Ernest Benn; 1925.

4. Thompson TC, Campbell RD, Arnold WD. Primary and secondary dislocation of the scaphoid bone. J Bone Joint Surg Br. 1964;46:73-82.

5. Dobyns JH, Linscheid RL. Fractures and dislocations of the wrist. In: Rock-wood CA Jr, Green DP, editors. Fractures. Vol 1. Philadelphia: JB Lippincott; 1975, p 345-440.

6. Nigst H. [Luxations and subluxations of the scaphoid bone]. Ann Chir. 1973;27:519. French.

SCAPHOID SUBLUXATION TEST see SCAPHOID STRESS TEST

SCAPHOID VIEW (FIGURE 56; see also FIGURE 60) see SEMIPRONATED OBLIQUE VIEW

SYNONYMS: navicular view or projection, scaphoid projection

Fig. 56b

Fig. 56a

SCAPHOID VIEW: a) the ulnar side of the wrist rests on the cassette or

table and the radial side of the wrist is elevated about 20° off the

table. The central x-ray beam is angled at the waist of the scaphoid,

35° toward the elbow. b) This view elongates the waist of the scaphoid

to produce an elongated oblique view of the scaphoid. This represents

one of several scaphoid views. (Reprinted with permission from Gilula





CLINICAL: a radiographic projection designed to show the long axisof the scaphoid (see RADIOLOGIC)

RADIOLOGIC: several radiographic PA projections have been de-scribed that more accurately portray the long axis of the pronatedscaphoid and provide a nonforeshortened (en face) or even elongatedview of the scaphoid waist. Two more commonly used projectionsare: 1) PA positioning, in which the hand is placed in a loose fist andulnar deviation, and the radiographic beam is directed perpendicular(dorsopalmar) to the imaging cassette through the scaphoid waist;and 2) PA positioning, in which the hand is ulnar deviated whilemaintaining the palm flat on the imaging cassette, and the radio-graphic beam is angled 15-20° proximally (dorsopalmarly), from thefingers toward the elbow.

COMMENTS: 1) such projections displaying the scaphoid waist canbe obtained with any position of the elbow, but standard positioningwith elbow flexed 90° and held at shoulder height may be preferablein attempts to standardize PA views of the wrist by each radiologictechnologist. 2) Other techniques have been described, includinguse of a box to hold a radiographic screen at an angle to the wrist.Many other views are available to evaluate the scaphoid, and thosecan be seen in a variety of textbooks for radiographic positioning. 3)Because of different potential planes of a fracture line, it is possiblethat a fracture may show better with different angles of the radio-graphic beam.



ders; 1996. p 126-45.


SCAPHOLUNATE ADVANCED COLLAPSE (SLAC) (FIGURE 57)

SYNONYM: scapholunar advanced collapse

CLINICAL: 1) progressive degenerative joint disease beginningwith the radioscaphoid articulation and progressing to involve thecapitolunate articulation, usually with sparing of the radiolunatejoint. 2) A special pattern of progressive, posttraumatic degenera-tive arthritis of the carpus, secondary to altered stress patterns thatoccur around an unstable scaphoid. This usually begins at the ra-dial styloid and scaphoid contact areas, progresses to the scaphoidsulcus and scaphoid articulation, then to the capitolunate joint, of-ten the scaphotrapeziotrapezoidal joints, and eventually to othercarpal joints, but usually sparing the radiolunate joint. It is similarto the pattern of osteoarthritis that develops around an unstablefracture or nonunion of the scaphoid, but not identical. 3) A formof progressive degenerative arthritis following a dissociative lesionof the scapholunate joint or through the scaphoid, which classicallybegins with the radioscaphoid articulation and progresses to in-volve the capitolunate joint (and often the scaphotrapeziotrapezoi-dal joint), while sparing the radiolunate articulation until very late.

RADIOLOGIC: the earliest changes occur as sharp spurring at thearticular-nonarticular junction on the radial side of the scaphoid andat the radial styloid tip with loss of the normal rounded curvature ofthe radial styloid. This progresses to narrowing of the radioscaphoidjoint, followed by narrowing of the capitolunate joint. In a similarfashion, narrowing of the joint between the hamate and lunate mayoccur. Scapholunate dissociation or malunion or nonunion of thescaphoid is commonly present (see COMMENTS).

COMMENTS: 1) SLAC most commonly occurs because of scapholu-

nate disruption, but it can also occur because of some other condi-tion, such as scaphotrapeziotrapezoidal disease. 2) This pattern ofchanges could also be called something else—such as degenerativejoint disease of the radiocarpal joint secondary to scapholunate liga-ment disruption. 3) Rarely, capitolunate joint narrowing may beginbefore radioscaphoid degenerative joint disease. 4) Late, one may seeendochondral new bone formation on the palmar surface of the lu-nate that effectively changes lunate contour and blocks lunate flexion.5) SLAC is the usual pattern of posttraumatic arthritis followingscapholunate dissociation. 6) Dorsal translation of the capitate withextension of the lunate (DISI) is commonly found on the lateralradiograph. 7) Although the problem appears to start at the scapho-lunate (SL) joint (with SL disruption), the primary clinical conse-quence is radioscaphoid degenerative joint disease. 8) Because theradiolunate joint is one of the last to become significantly involved, itis often available for stress loading, and the popular SLAC Wrist Pro-cedure (Watson) of excising the scaphoid, aligning the lunate prop-erly between the radius and capitate, and then fusing the midcarpaljoint is often done to salvage many SLAC wrists. 9) The pattern of ar-thritis progression is very similar in patients with scaphoid non ormalunion, and the same salvage procedures are often used for theSNAC (scaphoid nonunion advanced collapse) as for the SLAC wrist.

Fig. 57a

SCAPHOLUNATE ADVANCED COLLAPSE (SLAC): a) PA view: scapholu-

nate diastasis, degenerative joint disease at the radiocarpal and capi-

tolunate joints, and preserved radiolunate joint width is present. b)

Lateral view: dorsal tilting of the lunate and palmar tilting of the

scaphoid result in a scapholunate angle of 70°. See text. L = lunate

axis, R = radius axis, S = scaphoid axis, and C = capitate axis. Radiolu-

nate angle is 20° and capitolunate angle is 5°. c) In a different patient,

the same pattern of scapholunate widening associated with degenera-

tive joint disease at the radioscaphoid and capitolunate joints is

present; however, in this case there is also extensive volume loss of

the proximal pole of the scaphoid and erosive change in the scaphoid

fossa. This pattern is more consistent with CPDD (calcium pyrophos-

phate deposition disease), whereas the pattern in Fig. 57A is seen

most commonly without CPDD. (Reprinted with permission from Gilula


Saunders; 1996. p 539-40. Fig 20-24, A and B; and 25.)



The major difference between the SNAC and SLAC wrists is that theproximal scaphoid fracture fragment in the SNAC wrist acts as asmall lunate, and the articulation of this proximal fracture fragmentwith the radius is usually normal. Also, the scapholunate ligamentand joint are usually preserved in the SNAC wrist.


REFERENCES:1. Sebald JR, Dobyns JH, Linscheid RL. The natural history of collapse deformi-

ties of the wrist. Clin Orthop. 1974;104:140-8.

2. Watson HK, Ballet FL. The SLAC wrist: scapholunate advanced collapse pat-tern of degenerative arthritis. J Hand Surg [Am]. 1984;9:358-65.


SCAPHOLUNATE DISSOCIATION (SLD) (FIGURE 58; SEE ALSO FIGURES 54A AND 57A)

SYNONYMS: see comment #1

CLINICAL: loss of synchronous motion or normal alignment be-tween the scaphoid and the lunate

RADIOLOGIC: measured at the midpoint of the scapholunate jointon the PA view, a scapholunate gap greater than 4 mm or double thewidth of other intercarpal spaces, especially twice as wide as a normalcapitolunate joint. The radioscaphoid joint may be abnormally de-creased (see ROTARY SUBLUXATION OF THE SCAPHOID).

COMMENTS: 1) several words are used as synonyms for SLD, butthey are not true synonyms. Scapholunate diastasis (Terry ThomasSign), or widening of the SL joint, may not always be present withSLD. When SL diastasis is definitely present, scapholunate dissocia-tion should be present. See ROTARY SUBLUXATION OF THESCAPHOID for commentary that RSS and SLD may not be synony-mous. 2) Some people have an abnormally wide scapholunate spacebut a normal scapholunate ligament. One example of this is in a pa-tient with lunotriquetral coalition. 3) Typically this should not be as-sociated with the DISI pattern with abnormal dorsal lunate tilting. IfDISI is present, then more anatomic structures should be abnormalthan as seen with only RSS. 4) In the past, scapholunate joint spacewidening was termed “Terry Thomas Sign” for the space between thefront teeth of that English actor. More recently, some people havecalled this the Leon Spinks’ Sign (a boxer), and the David LettermanSign (a television talk-show host) for the space these people have be-tween their front teeth (see comment #1). 5) Eventually, SLD leads tosimilar malalignment at the other scaphoid joints. 6) In the imma-ture carpus, this space may appear wider because unossified cartilagi-nous portions of the scaphoid and lunate are present adjacent to thejoint space. 7) Although there is a subtle difference in use of the terms“rotary subluxation of the scaphoid vs. scapholunate dissociation(RSS focuses attention to the scaphoid; SLD emphasizes that bothscaphoid and other carpal elements are disturbed), they are used asequivalent terms by many wrist investigators. The discussion for RSSthen can be closely applied to SLD. Each includes the entire spectrumof extremely subtle scaphoid instability to a certain pattern of fixeddeformity with associated arthritis with many intermediate stages be-tween. Whatever one calls this common carpal instability, both diag-nosis and treatment have suffered from not recognizing that there areseveral stages to the condition and that some recommended treat-ments are appropriate at one stage but not at the others.


REFERENCES:1. Dobyns JH, Perkins JC. Instability of the carpal navicular. Proceedings of the

American Academy of Orthopaedic Surgeons. J Bone Joint Surg Am. 1967;49:1014.


3. Mayfield JK, Johnson RP, Kilcoyne RK. Carpal dislocations: pathomechanics and progressive perilunar instability. J Hand Surg. 1980;5:226-41.

4. Taleisnik J. Scapholunate dissociation. In: Strickland JW, Steichen JB, editors. Difficult problems in hand surgery. St. Louis: CV Mosby; 1982. p 341-8.


Fig. 57b

Fig. 57c



6. Schernberg F. Roentgenographic examination of the wrist: a systematic study of the normal, lax, and injured wrist. Part 2: stress views. J Hand Surg [Br]. 1990;15;220-8.

7. Saffar P. Carpal injuries: anatomy, radiology, current treatment. France: Springer; 1990.

8. Cooney WP 3rd, Linscheid RL, Dobyns JH. Carpal instability: treatment of liga-ment injuries of the wrist. AAOS Instr Course Lect. 1992;41:33-44.

9. Lavernia CJ, Cohen MS, Taleisnik J. Treatment of scapholunate dislocations by ligamentous repair and capsulodesis. J Hand Surg [Am]. 1992;17:354-9.

SCAPHOLUNATE INSTABILITY see LONGITUDINAL(COLUMNAR) INSTABILITY PATTERN

SCAPHOPISOCAPITATE (SPC) LATERAL (SEE FIGURE 35B)

SYNONYMS: scaphopisotriquetral relationship, scaphopisotriquetralalignment

CLINICAL: this is a method utilizing points of the scaphoid (S), pisi-form (P), and capitate (C) to determine adequacy of a lateral radio-graph of the wrist, relying on the carpal and not the forearm bones.

RADIOLOGIC: an excellent lateral position of the carpus can be rec-ognized on a radiograph when the ventral cortex of the pisiformprojects midway between the ventral surfaces of the capitate head andthe distal pole of the scaphoid. Acceptable position is when the ven-tral cortex of the pisiform may not be in the midpoint but still liesdorsal to the ventral cortex of the distal pole of the scaphoid and ven-tral to the ventral cortex of the head of the capitate. When the ventralcortex of the pisiform projects ventral to the ventral cortex of the dis-tal pole of the scaphoid or dorsal to the ventral cortex of the capitate,the SPC alignment is considered inadequate, especially for evaluationof carpal relationships. These are the SPC (scaphopisocapitate) align-ment criteria.

COMMENTS: 1) the SPC relationship was designed to identify car-pal position. A long-used technique, checking alignment between theulnar styloid and the dorsal rim of the radius is actually checking thealignment of the forearm. In any individual case, both may be ade-

quate; however, in some patients with a prominent distal ulna andother congenital variations of the wrist, the radius and ulnar overlapmethod may not prove reliable. 2) When the carpus is not adequatelyaligned, as when the SPC relationship is inadequate, carpal alignmentmay be misinterpreted and the slope of the distal radius may be erro-neously evaluated. Such inadequate assessment of the distal radiusslope is especially common when evaluating the position of the distalradius articular surface after reduction of a distal radius fracture.


REFERENCE:1. Yang Z, Mann FA, Gilula LA, Haerr C, Larsen CF. Scaphopisocapitate alignment:

criterion to establish a neutral lateral view of the wrist. Radiology. 1997;205:865-9.

SCAPHOTRAPEZIOTRAPEZOIDAL (STT) JOINT(FIGURE 59; SEE ALSO FIGURE 60B)

SYNONYMS: triscaphe joint, radial midcarpal joint

CLINICAL: joint formed by the articulation of the proximal surface ofthe trapezium and trapezoid with the distal surface of the scaphoid.Some authors believe this joint also includes the joint between the tra-pezium and trapezoid.

RADIOLOGIC: see CLINICAL. This joint area can usually be seenbest with some degree of semipronated oblique. Fluoroscopic spots orproperly positioned computed tomographic or “routine” (especiallycomplex-motion thin-section) tomographic sections can be utilizedto profile each portion of these articulating surfaces.

Fig. 58

SCAPHOLUNATE DISSOCIATION (SLD): scapholunate widening (diasta-

sis) is pronounced and is much wider than the capitolunate joint.

Foreshortening of the scaphoid and decreased scaphoid cortical ring

distance are present (see ROTARY SUBLUXATION OF THE SCAPHOID).

Fig. 59a

SCAPHOTRAPEZIOTRAPEZOIDAL (STT) JOINT: a) this view is made with

the radial side of the hand elevated 45° off the x-ray cassette or x-ray

table and with the wrist in ulnar deviation. The central ray (indicated

by the pointer) is passed through the trapezium perpendicular to the

cassette. The wrist can be supported with a wedge sponge. b) On this

PA axial oblique view, the joints between the scaphoid and trapezium

(scaphotrapezial), the scaphoid and trapezoid (scaphotrapezoidal),

and the trapezium and trapezoid (trapeziotrapezoidal) are seen. All of

these together are referred to as the STT joint. Some people call this

group of joints the triscaphe joint. (Reprinted with permission from

Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia:




COMMENTS: 1) some experts do not support the use of the term“triscaphe joint.” 2) It is intriguing that the deformity in progres-sive arthritis of this joint is the opposite of the SLD/RSS position,i.e., with disease of the STT joint, the scaphoid becomes more ex-tended with a smaller scapholunate angle. The joint is probablymore of a factor in the dynamics of the radial column than is cur-rently acknowledged.


REFERENCES: 1. Crosby EB, Linscheid RL, Dobyns JH. Scaphotrapezial trapezoidal arthrosis.

J Hand Surg. 1978;3:223-4.

2. see ROTARY SUBLUXATION OF THE SCAPHOID

SEMIPRONATED OBLIQUE VIEW (FIGURE 60)

SYNONYMS: radial oblique navicular view, radial oblique scaphoidview, scaphoid view, semipronated oblique projection/position

CLINICAL: provides an oblique nonforeshortened view of thescaphoid and shows the trapeziotrapezoidal and the scaphotrapezio-trapezoidal articulations

RADIOLOGIC: the wrist is positioned so that the radial side of thewrist is elevated 45° off the film cassette. The central ray of the x-raybeam is centered to pass through the radial aspect of the head of thecapitate from dorsal to palmar.

COMMENTS: this is the best view to examine the STT joint and isvaluable to examine the scaphoid.


REFERENCES:1. radiologic technology textbooks


SEMISUPINATED OBLIQUE VIEW (FIGURE 61)

SYNONYMS: pisiform view, pisotriquetral view, ulnovolar carpalprojection, a “hook of the hamate” view, semisupinated oblique pro-jection/position

CLINICAL: a radiographic view designed to demonstrate the pisi-

Fig. 59b

Fig. 60b

Fig. 60a

SEMIPRONATED OBLIQUE VIEW: a) the radial side of the wrist is ele-

vated 45° off the cassette or table top. A 45° sponge can be used

to support the wrist. The central ray (indicated by the pointer) is

aimed to the waist of the scaphoid at its junction with the capitate.

b) The produced radiograph shows the scaphotrapeziotrapezoidal

joint, the waist of the scaphoid, and the other carpal bones in an

oblique position displaying ventral radial and dorsoulnar surfaces of

all the carpal bones. The first carpometacarpal joint may also be

well profiled, and the trapezium can be seen more in a posteroante-

rior projection. (Reprinted with permission from Gilula LA, Yin Y, edi-

tors. Imaging of the wrist and hand. Philadelphia: WB Saunders;

1996. p 127. Fig 5-32, A and B.)



form, the pisotriquetral joint, and the palmar aspects of the hamateand triquetrum

RADIOLOGIC: the ulnar aspect of the hand and wrist are placed onthe cassette with the radial side of the wrist supinated 30-45° fromthe neutral lateral position. This results in the palm facing upward.The central beam passes palmar to dorsal at the head of the capitatemidway between the radial and ulnar borders of the wrist.

COMMENTS: 1) this is the best or one of the best radiographic viewsto profile the pisotriquetral joint, and the volar ulnar column to dis-play the hook of the hamate and the important ligament origin-insertion area at the volar aspect of the triquetrum. 2) Profile of thisjoint can be optimized with fluoroscopic control.


REFERENCES:1. radiologic technology textbooks


SIDE VIEW see LATERAL VIEW

SIGMOID NOTCH OF DISTAL RADIUS see SIGMOIDSULCUS OF DISTAL RADIUS

SIGMOID SULCUS OF DISTAL RADIUS (SEE FIGURE 27)

SYNONYMS: sigmoid notch of the distal radius, radius portion ofthe distal radioulnar joint

CLINICAL: the concave articular groove on the ulnar side of the dis-tal radius constituting the radial part of the distal radioulnar joint(DRUJ) and into which the distal ulna articulates


COMMENTS: 1) the anatomy of this structure and its relationship tothe distal ulna can be readily and most accurately displayed by com-puted tomography or MRI, especially in the axial plane. 2). Abnor-malities may be more obvious clinically than by standard x-raytechniques.

CODE: Anatomic: Ulnar (IIC)

REFERENCE:1. Forstner H. [Morphology of the distal radio-ulnar joint. Surgical orthopedic con-

sequences]. Handchir Mikrochir Plast Chir. 1990;22:296-303. German.

SLIDER-CRANK MECHANISM (FIGURE 62)

SYNONYMS: carpal revolute or scaphoid slider-crank mechanism

CLINICAL: a specialized version of a mechanical engineering con-cept of a four-bar linkage in which one of the three revolute linkagesis substituted by a prismatic linkage. The best example is the drivemechanism on a steam locomotive where the prismatic linkage isequivalent to the piston in the steam chamber, and the revolute link-ages are those on the drive wheels of the locomotive. The clinicalanalogy is the scaphoid bone, which may be thought of as having aprismatic linkage at the scaphotrapeziotrapezoidal joint and one rev-olute linkage at the dorsal aspect of the scapholunate and a secondrevolute linkage at the capitolunate and radiolunate joints. The anal-ogy is an attempt to show the stabilizing effect of the scaphoid in thesagittal plane as it passes at a 45° angle between the centers of rota-tion of the distal and the proximal carpal rows, with the centers of ro-

Fig. 61a

SEMISUPINATED OBLIQUE VIEW: a) the wrist is positioned with its

ulnar side on the cassette or x-ray tabletop and the radial side of

the wrist supinated 30-45° from true lateral, or elevated 45-60° off

the cassette or tabletop. The central ray (indicated by the pointer) is

aimed toward the capitate head. b) This view demonstrates the

pisotriquetral joint (between arrowheads), the dorsoradial surface

of the waist of the scaphoid (white arrow), the hamate hook (black

arrow), and the ventroulnar surfaces of the triquetrum, lunate,

hamate, and capitate. (Reprinted with permission from Gilula LA,

Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB


Fig. 61b



tation assumed to be in the mid neck of the capitate and on the distalarticular surface of the lunate.


COMMENTS: 1) this simple analogy is now principally of historicalinterest, too simple to actually explain carpal mechanics. 2) This is asimple analogy in which mechanical does not seem to fit with motil-ity. 3) Although seldom needed except to illustrate the definition, ei-ther multiple static or the dynamic sequence of lateral views betweenfull extension and full flexion of the carpus will illustrate the concept.


REFERENCES: 1. Gilford WW, Bolton RH, Lambrinudi C. The mechanism of the wrist joint with

special reference to fractures of the scaphoid. Guy’s Hosp Rep. 1943;92:52-9.

2. Landsmeer JMF. Studies in the anatomy of articulation. I. The equilibrium of the “intercalated” bone. Acta Morphol Neerl Scand. 1961;3:287-321.



5. Ritt MJPF. Biomechanical studies on ulnar-sided ligaments of the wrist. Akade-misch Proefschrift (PhD thesis). Nederland: Universiteit van Amsterdam; 1995. ISBN#90-9008564-5.

SPC LATERAL see SCAPHOPISOCAPITATE LATERAL

SPRAIN

SYNONYM: partial ligament tear

CLINICAL: 1) a sprain is a ligamentous injury characterized by painand sometimes a change in the dimensions of the affected ligamentswith or without a loss of the structural integrity of the ligaments.Pathophysiologically, a sprain represents micro-tears within the sub-stance of the ligament and thus is a partial disruption of the ligamenton a microscopic level. 2) A spectrum of ligament injury rangingfrom a micro-tear with no perceptible loss of integrity to a variety of

partial tears with varying degrees of structural loss to a complete tearwith total loss of functional competence. 3) A stretching, twisting, orbending injury of a ligament compromising its structural integritybut leaving it in continuity.

RADIOLOGIC: radiographically, a sprained ligament may appear nor-mal on a routine radiograph. A sprain may also appear as a slight wid-ening of the interosseous distance between two bones of a magnitudeless than one would expect with a loss of integrity of the ligament. Asprained ligament will always appear normal on an arthrogram be-cause it is intact.

COMMENTS: 1) currently, we know of no reliable means to make animaging diagnosis of a sprain with certainty. In the future, MRI or ul-trasound with ultra-high spatial resolution may become diagnosti-cally useful. 2) A sprained ligament may or may not be associatedwith functional stability. 3) For diagnosis and management, the de-gree of a sprain should be known or at least estimated. This plus thehealth status and the functional requirements of the damaged indi-vidual guide treatment selection. In the wrist, as in other joints of thebody, attritional damage occurs, often with minimal loss of func-tional competence and few or no symptoms. 4) Clinical estimatesaided by the standard x-ray findings of normality or swelling or os-seous involvement or stressed displacement have served reasonablywell to document sprain in its various stages. 5) It is obvious from theprior comments that a better and more complete imaging analysis ofsprains is needed, and such differentiation is even now being at-tempted in the management of high-profile athletes.


REFERENCE:1. radiology or sports medicine textbooks

STATIC CARPAL INSTABILITY(SEE FIGURES 12-16, 29, 54, 57, 58)

SYNONYMS: fixed carpal instability, static deformity, permanentcarpal instability

CLINICAL: a malalignment of the carpal bones associated with car-pal ligament or bone damage evident in the neutral PA and/or lateralradiographs in the absence of malunion of the distal radius and with-out stress or other provocative maneuvers (see COMMENTS)


COMMENTS: 1) “fixed” is suggested by some as a synonym for staticcarpal instability. However, a static deformity is not necessarily“fixed.” For instance, chronic rotatory subluxations of the scaphoid(by definition static) are not necessarily fixed, since they may be re-duced by pushing the scaphoid with the thumb. Some experts believethat a condition, as with some cases of VISI and DISI that cannot bemanipulated back and forth from a nonanatomic to an anatomic po-sition, cannot be a true instability because no real “instability” ispresent. 2) In another interpretation, the static instabilities shouldnot be considered to be permanently fixed, since they have pro-gressed to the current degree of deformity but may progress furtherwith time and stress. 3) When a malalignment is solidly “fixed,” it is acontracture, a collapse, or a persistent deformity, but it is not “insta-bility.” For this reason, some experts challenge the accepted conven-tion of the use of the word “instability” in these cases. Some of theseexperts believe that the word “malalignment” would be a better de-scriptive term than “instability.” One expert states: “In this context,the term ‘instability’ is not correct. It is confusing to those who ad-here to its definition in physics, and in medicine in other joints than

Fig. 62

SLIDER-CRANK MECHANISM: this figure shows a “slider-crank” in

which the scaphoid acts as a bridge between the proximal and distal

carpal rows controlling intercarpal motion much as the piston and

crank shaft do in a compressor. C = capitate, L = lunate, S =

scaphoid, R = radius. See text. (Reprinted with permission from Ritt

MJPF. Biomechanical studies on ulnar-sided ligaments of the wrist.

Akademisch Proefschrift [PhD Thesis]. Nederland: Universiteit van

Amsterdam; 1995. p 12. Fig 1.2.)



the wrist. Furthermore, its current use ‘blocks’ the term and abol-ishes its use in the correct meaning of the word. I would certainlyprefer terms such as ‘tilt,’ ‘shift,’ ‘subluxation,’ ‘malalignment,’ etc.” 4)Static instability is in contrast to a dynamic instability in which thestandard radiographs are normal and the instability is only evidenton cine or video fluoroscopic studies combined with provocative ma-neuvers of the wrist. 5) An adaptive carpus may be considered a staticdeformity pattern (not instability). 6) Some experts have difficultywith the terms “static” and “dynamic.” As one expert states: “An in-stability is always dynamic. A ‘static’ instability is a contradiction, ifwe analyze the words correctly.”


REFERENCES: 1. Vaughan-Jackson OJ. A case of recurrent subluxation of the carpal scaphoid. J

Bone Joint Surg Br. 1949;31:532-3.



STATIC DEFORMITY see STATIC CARPAL INSTABILITY

STRESS INSTABILITY see DYNAMIC INSTABILITY

STRESS TEST see PROVOCATIVE MANEUVER

SUBLUXATION (SEE FIGURES 6, 20)

SYNONYMS: partial or incomplete dislocation, partial or incom-plete luxation

CLINICAL: an abnormal and incongruent but partial contact be-tween the articular surfaces of a joint, as opposed to a dislocation inwhich there is no contact between articular surfaces of a joint


COMMENT: use of the term “subluxation of joint” is seldom heardwhen carpal instabilities are being discussed, and the term is onlyneeded to indicate that many of the common instabilities show lessdeformity and less instability than a dislocation.


REFERENCES:1. see STATIC CARPAL INSTABILITY

2. see SCAPHOID SUBLUXATION/DISLOCATION

TETHER

SYNONYMS: limiting band, restricting structure or attachment, at-tach, anchor, constraint, tie

CLINICAL: a structure of anatomic or implant tissues that restrictsthe mobility of a bone or tendon or any moving structure

RADIOLOGIC: see COMMENTS

COMMENTS: 1) such a structure itself may be visible by imagingtechniques, but more likely its effects will be noticeable. 2) Some peo-ple believe that the term is similar enough to its dictionary definition(“a rope or chain that restricts the motion of an animal”) that it is al-most immediately recognizable and does not need to be defined sep-arately for the wrist and hand. 3) Techniques of tethering a carpalbone or bones are quite commonly used in the carpus, although theyare seldom given much mention. The tether method most commonly

used is probably the Blatt technique of constructing a dorsal capsulartether to restrain the scaphoid against excessive flexion.


REFERENCE:1. Blatt G. Capsulodesis in reconstructive hand surgery: dorsal capsulodesis for

the unstable scaphoid and volar capsulodesis following excision of the distal ulna. Hand Clin. 1987;3:81-102.

THENAR see RADIAL

TRANSAXIAL PLANE see TRANSVERSE PLANE

TRANSOSSEOUS PERILUNATE INJURIES see GREATERARC INJURIES

TRANSVERSE INSTABILITY PATTERN

SYNONYMS: row instability, ring disruption

CLINICAL: a classification system that recognizes that carpal insta-bilities usually occur in the transverse plane secondary to forces di-rected transversely across the wrist. For instance, scapholunateinstability, lunotriquetral (lunatotriquetral, triquetrolunate) instabil-ity, and perilunate dislocations occur because of a perilunate forcethat can create these injuries in sequence. (See COMMENTS.)

RADIOLOGIC: NA

COMMENTS: 1) although many experts do not support this con-cept, others still do. 2) It is believed by some that this pattern hasbeen demonstrated and confirmed in studies by Mayfield andJohnson. Some of these same people believe that transverse instabil-ity patterns also include midcarpal instabilities (see MIDCARPALINSTABILITY) as well as radiocarpal instabilities (dorsal radiocarpalinstability, palmar radiocarpal instability, and ulnar proximal carpalinstability). Ulnar carpal instabilities can be subdivided into (a)rheumatoid (synovial based), (b) iatrogenic, and (c) traumaticcauses. 3) Axial instabilities fall outside this general etiologic term. 4)The term “lunotriquetral” is preferred to “triquetrolunate” by manyto follow the general rule to name ligaments from radial to ulnar.

CODE: Clinical conditions: Sprains-Instabilities-Subluxations (IIIB)

REFERENCES: 1. MacConaill MA. The mechanical anatomy of the carpus and its bearing on

some surgical problems. J Anat. 1941;75:166-75.

2. Lichtman DM, Martin RA. Introduction to the carpal instabilities. In: Lichtman DM, editor. The wrist and its disorders. Philadelphia: WB Saunders; 1988. p 244-50.

3. Cooney WP 3rd, Linscheid RL, Dobyns JH. Fractures and dislocations of the wrist. In: Rockwood CA JR, Green DP, Bucholz RW, Heckman JD, editors. Frac-tures in adults. 4th ed. Philadelphia: Lippincott-Raven; 1996. p 745-868.


TRANSVERSE PLANE (SEE FIGURE 27)

SYNONYMS: cross section, dorsal-to-volar plane, axial plane, trans-axial plane

CLINICAL: 1) dorsopalmar plane at right angles to the longitudinalaxis of the hand. 2) Dorsopalmar plane at right angles to the longitu-dinal axis of the body, including the upper limb.


COMMENT: views in this plane are much more common now thatcomputed tomography and MRI imaging are frequently used.





TRIQUETROHAMATE INSTABILITY (SEE FIGURE 16)

SYNONYMS: ulnar midcarpal instability (UMI) (see comment #3),medial anterior midcarpal instability (MAMI)

CLINICAL: 1) loss of the ability to keep a normal anatomic and/orkinematic relationship between the triquetrum and the hamate un-der physiologic loads. Usually due to rupture of the palmar triquetro-hamatocapitate ligament. 2) Usually associated with lack of integrityin or around the space of Poirier, which is usually associated withCIND-VISI, contrasted to the CID-VISI, which is associated with“lunotriquetral dissociation.”

RADIOLOGIC: not yet defined

COMMENTS: 1) although the key ligament disruption is often in the

ulnar volar arcuate (triquetro-hamate-capitate ligament) system, ad-ditional weakness around the “space of Poirier” contributes, and theproximal carpal row collapses as a unit unless there is also a lunotri-quetral injury. For this reason, this condition is usually referred to asa “midcarpal instability,” but this also is problematic since someCIND-VISI collapse of the proximal carpal row occurs from radio-carpal ligament injury or from combinations of radiocarpal and mid-carpal injury. 2) This is a condition accepted by some experts and notrecognized by others. Therefore, with time, this may become moreaccepted or may be dropped as a true clinical condition. 3) There issome question if triquetrohamate instability and ulnar midcarpal in-stability are true synonyms.


REFERENCES: 1. Lichtman DM, Schneider JR, Swafford AR, Mack GR. Ulnar midcarpal insta-

bility—clinical and laboratory analysis. J Hand Surg [Am]. 1981;6;515-23.

2. Taleisnik J. Triquetrohamate and triquetrolunate instabilities (medial carpal in-stability). Ann Chir Main. 1984;3:331-43.

3. Schernberg F. Roentgenographic examination of the wrist: a systematic study of the normal, lax and injured wrist. Part 1: The standard and positional views. J Hand Surg [Br]. 1990;15:210-9.

4. Schernberg F. Roentgenographic examination of the wrist: a systematic study of the normal, lax, and injured wrist. Part 2: stress views. J Hand Surg [Br]. 1990;15:220-8.

5. Saffar P. Midcarpal instability. In: Saffar P, editor. Carpal injuries: anatomy, radi-ology, current treatment. Paris: Springer; 1990. p 83-7.


7. Dobyns JH. Carpal instability—a review. In: Nakamura R, Linscheid RL, Miura T, editors. Wrist disorders—current concepts and challenges. Tokyo: Springer; 1992. p 239-46.

TRIQUETROLUNATE BALLOTTEMENT (FIGURE 63)

SYNONYMS: dorsovolar triquetrolunate translation or displacementtest, triquetrolunate (lunotriquetral) shear test, Reagan-Linscheidtest, lunotriquetral ballottement (see comment #2)

CLINICAL: a clinical test in which the triquetrum and pisiform areheld between the thumb and index finger of one examining hand,and the lunate is held similarly by the other hand. The examinerthen attempts to translate the triquetrum dorsally and palmarlywith regard to the lunate. The test is positive if there is excess mo-bility and/or crepitance between the triquetrum and lunate, espe-cially if different from the opposite side. The test should reproducethe patient’s pain.

RADIOLOGIC: NA

COMMENTS: 1) this test does not always define stability betweenjust the lunate and triquetrum but may also test the integrity of theligaments between the triquetrum and/or scaphoid and/or capitateand hamate. 2) Many patients have prominent mobility at the luno-triquetral [triquetrolunate (TL)] level. Such mobility alone is not aproblem when not accompanied by reproducible pain.

CODE: Tests (IV)

REFERENCES:1. Reagan DS, Linscheid RL, Dobyns JH. Lunotriquetral sprains. J Hand Surg

[Am]. 1984;9:502-14.

2. LaStayo P, Howell J. Clinical provocative tests used in evaluating wrist pain: a descriptive study. J Hand Ther. 1995;8:10-7.

3. Berger RA, Dobyns JH. Physical examination and provocative maneuvers of the wrist. In: Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saunders; 1996. p 23-42.

Fig. 63

TRIQUETROLUNATE BALLOTTEMENT: pressure is placed over the

lunate and triquetral bones to cause translation between these

bones and to see if pain of the presenting type is produced with

this maneuver. Such produced pain supports ligamentous disrup-

tion at this site. (Reprinted with permission from Gilula LA, Yin Y,

editors. Imaging of the wrist and hand. Philadelphia: WB Saun-

ders; 1996. p 17. Fig 2-20.)



TRIQUETROLUNATE DISSOCIATION see LUNOTRIQUETRALDISSOCIATION

TRIQUETROLUNATE (LUNOTRIQUETRAL) INSTABILITY seeLONGITUDINAL (COLUMNAR) INSTABILITY PATTERN

TRIQUETROLUNATE SHEAR TEST see TRIQUETROLUNATE(LUNOTRIQUETRAL) BALLOTTEMENT

TRISCAPHE JOINT (SEE FIGURE 59) seeSCAPHOTRAPEZIOTRAPEZOIDAL (STT) JOINT

SYNONYMS: scaphotrapeziotrapezoidal (STT) joint, distal scaphoidarticulation, radial midcarpal joint

CLINICAL: see STT joint


COMMENTS: 1) not a term unless used with the word “joint.” 2)The term was coined by Dr. Kirk Watson. 3) It is a contemporaryand controversial term without descriptive meaning or Latin rootorigin; however, it has been widely publicized in and out of the liter-ature and may survive. 4) Some experts consider this term “slang,”and consider “STT” a better contraction. Other experts do not acceptthis term.


REFERENCE:1. see SCAPHOTRAPEZIOTRAPEZOIDAL (STT) JOINT and ROTARY SUBLUXATION

OF THE SCAPHOID (RSS)

ULNAR see MEDIAL

SYNONYMS: medial, ulnolateral, hypothenar, little-finger side, ul-narward

CLINICAL: the side of the wrist occupied normally by the ulnar head,triangular fibrocartilage (TFC), triquetrum, hamate, and fourth andfifth metacarpal bases and the soft tissues enveloping them (seeMEDIAL)


COMMENTS: 1) ulnar is only an adjective, never a noun. 2) “Ulnar”occasionally means “of ulna” besides “medial,” as in ulnar collateralligament of the elbow joint. 3) The use of “ulnar” is more descriptiveand is less likely to be misused than the term “medial” when dealingwith the wrist.


REFERENCE:1. anatomy textbooks

ULNAR COLUMN (SEE FIGURE 21) see ROTARY COLUMN

SYNONYMS: medial column, rotary column

CLINICAL: the hamate, triquetrum, and triangular fibrocartilageand their articulations


COMMENTS: 1) see ROTARY COLUMN. 2) Some experts do notuse this term. 3) Some experts believe this is a more useful term than“rotary column,” but ulnar wrist and specific terminology for the ex-act location should suffice.

CODE: Anatomic: Ulnar (IIC)

REFERENCE:1. see ROTARY COLUMN

ULNAR IMPINGEMENT see IMPACTION SYNDROME, ULNOCARPAL

ULNAR INCLINATION OF DISTAL RADIUS seeRADIAL INCLINATION OF DISTAL RADIUS

ULNAR MIDCARPAL INSTABILITY (UMI) seeTRIQUETROHAMATE INSTABILITY

ULNAR OBLIQUE SCAPHOID VIEW/POSITION seeREVERSE PA OBLIQUE VIEW

ULNAR RADIOCARPAL SUBLUXATION see ULNAR TRANSLATION

ULNAR TRANSLATION (UT) OF THE CARPUS(FIGURE 64; FIGURE 22)

SYNONYMS: ulnar translocation, ulnar radiocarpal subluxation

CLINICAL: ulnar displacement of the hand at the radiocarpal jointrelative to the forearm.

RADIOLOGIC: 1) assessment is made on the zero (neutral) PA view(see COMMENTS). Qualitative and quantitative criteria exist. Quali-tatively, UT is diagnosed when >50% of the lunate projects ulnar tothe ulnarmost extent of the radiolunate fossa and the lunocapitatealignment remains normal (see reference #1). Also, when there is in-creased width of the radioscaphoid joint space compared to the radi-olunate joint space, UT may be present. Quantitatively, UT is presentwhen McMurtry’s index (“carpal-ulnar” distance) is <0.27 (see Mc-MURTRY’S INDEX). 2) Chamay measurement for ulnar translation(Figure 22) is a measurement calculating a ratio between the lengthof the third metacarpal and the distance between the radial styloidand the central portion of the capitate head to determine ulnar trans-lation of the carpus. A perpendicular line (L4) is measured between aline drawn proximal-distal (ARS) through the radial styloid processand the center of the head of the capitate through the carpal heightline (L2) and the length of the third metacarpal (L1). Normally theratio of ulnar translation (L4) to the length of the third metacarpal(L1) is defined as 0.28 ± 0.03 (see reference #2). 3) Two types of ulnartranslations are recognized (Taleisnik) from the radiographic stand-point: Type I, in which the entire carpus is displaced ulnarward, withwidening of the space between the radial styloid and the scaphoid;and Type II, in which the scaphoid retains an essentially normal rela-tionship to the radius, while the remainder of the carpus migrates ul-narly, creating an abnormal scapholunate gap.

COMMENTS: 1) the neutral PA position must be present as iden-tified by the central axis of the third metacarpal being parallel to themidplane of the radius. Radial deviation of the wrist normally movesthe lunate ulnar to the radius. 2) The Chamay method (“carpal-radial styloid” distance) of measuring UT using the radial styloidmay be better when the ulnar head is absent. Some people prefer thismethod to measure UT routinely. 3) Palmar carpal subluxation com-monly occurs simultaneously with ulnar carpal translation. 4) Ulnartranslation, Type II, differs from the usual SLD (scapholunate dis-sociation) in that with UT Type II, there is an element of extrinsic(capsular) ligament damage as well as the intrinsic (interosseous)ligament damage. 5) This is a true subluxation, which is not sponta-neously reducible.



CODES: Clinical Conditions: Sprain-Instabilities-Subluxations (IIIB);Radiologic: Measurements (IE)

REFERENCES:1. Gilula LA, Weeks PM. Post-traumatic ligamentous instabilities of the wrist.

Radiology. 1978;129:641-51.

2. Chamay A, Della Santa D, Vilaseca A. [Radiolunate arthrodesis. Factor of sta-bility for the rheumatoid wrist]. Ann Chir Main. 1983;2:5-17. French.

3. Rayhack JM, Linscheid RL, Dobyns JH, Smith JH. Posttraumatic ulnar transla-tion of the carpus. J Hand Surg [Am]. 1987;12:180-9.

4. Dibenedetto MR, Lubbers LM, Coleman CR. Relationship between radial incli-nation angle and ulnar deviation of the fingers. J Hand Surg [Am]. 1991;16:36-9.

5. Pirela-Cruz MA, Firoozbakhsh K, Moneim MS. Ulnar translation of the carpus in rheumatoid arthritis: an analysis of five determination methods. J Hand Surg [Am]. 1993;18:299-306.

6. Viegas SF, Patterson RM, Ward K. Extrinsic wrist ligaments in the pathome-chanics of ulnar translation instability. J Hand Surg [Am]. 1995;20:312-8.

7. McMurtry RY, Youm Y, Flatt AE, Gillespie TE. Kinematics of the wrist. II. Clinical applications. J Bone Joint Surg Am. 1978;60:955-61.

8. Taleisnik J. Classification of carpal instability. Bull Hosp Jt Dis Orthop Inst. 1984;44:511-31.

9. Taleisnik J. Current concept review. Carpal instability. J Bone Joint Surg Am. 1988;70:1262-8.

ULNAR TRANSLOCATION see ULNAR TRANSLATION

ULNAR/ULNA VARIANCE (FIGURE 65)

SYNONYMS: ulnar variant, ulna variant

CLINICAL: relative level of the ulna (center of distal subchondralsurface) to that of the radius at the subchondral surface of the distalradioulnar joint (DRUJ). This level is classified as minus when ulnarlength is shorter than the radius, plus (positive) when the ulna islonger, and neutral or zero when both are approximately equal.

RADIOLOGIC: the zero (neutral) PA view is used for determina-tion (see NEUTRAL POSTEROANTERIOR VIEW for exact posi-tioning). Two reproducible methods of measurement can be used:1) extend a line perpendicular to the long axis of the distal radiusfrom the midportion of the ulnar aspect of the subchondral surfaceof the distal radius toward the ulna and measure the shortest dis-tance between this line and the distalmost subchondral carpal sur-face of the ulna, excluding the ulnar styloid (reference #1); and 2)with use of a template of concentric circles placed to best fit thecontour of the articular margin of the distal radius, the concentriccircle that best approximates the distal radial surface is selected as areference and compared in millimeters to the carpal surface of theulna (reference #2).

COMMENTS: 1) since the ulnar length varies between individualsand ethnic groups, there are no real “abnormal” values. However, it isnot common to find a variance of more than 3 mm either way. 2)Precise positioning (elbow should be flexed 90° and abducted toshoulder height) is necessary for reproducible measurement of ulnarvariance. Recognizing that the groove of the extensor carpi ulnaristendon is radial to the midpoint of the ulnar styloid, or preferably ra-dial to the base of the ulnar styloid, can help validate correct posi-

Fig. 64a

ULNAR TRANSLATION (UT): a) ulnar translation Type I (the entire carpus is moved ulnarly) is recognized here with the radioscaphoid joint wider

than all the other intercarpal and the radiolunate joints. Also, more than one half the width of the lunate projects ulnar to the edge of the radius

with the wrist in neutral position (third metacarpal is coaxial with the midaxis of the radius). b) Type II ulnar translation is recognized when the

radioscaphoid joint is normal, but the remainder of the carpus, identified by the position of the lunate with respect to the radius, is displaced

ulnarly (as described in part “a” of this caption). The wrist is in slight radial deviation, which demonstrates the scapholunate dissociation and

the ulnar lunate displacement. However, this illustration emphasizes the concept of the Type II ulnar translation. (Reprinted and modified with

permission from Gilula LA, Yin Y, editors. Imaging of the wrist and hand. Philadelphia: WB Saunders; 1996. p 209. Fig 8-7B.)

Fig. 64b



tioning (reference #6). 3) The ulnar head moves distally in pronationand proximally in supination.


REFERENCES: 1. Gelberman RH, Salamon PB, Jurist JM, Posch JL. Ulnar variance in Kienböck’s

disease. J Bone Joint Surg Am. 1975;57:674-6.

2. Palmer AK, Glisson RR, Werner FW. Ulnar variance determination. J Hand Surg [Am]. 1982;7:376-9.

3. Kristensen SS, Thomassen E, Christensen F. Ulnar variance determination. J Hand Surg [Br]. 1986;11:255-7.

4. Czitrom AA, Dobyns JH, Linscheid RL. Ulnar variance in carpal instability. J Hand Surg [Am]. 12;1987:205-8.

5. Schuind FA, Linscheid RL, An KN, Chao EY. A normal data base of posteroante-rior roentgenographic measurements of the wrist. J Bone Joint Surg Am. 1992;74:1418-29.

6. Jedlinski A, Kauer JM, Jonsson K. X-ray evaluation of the true neutral position of the wrist: the groove for extensor carpi ulnaris as a landmark. J Hand Surg [Am]. 1995;20:511-2.

ULNAR/ULNA VARIANT see ULNAR VARIANCE

ULNOCARPAL ABUTMENT see

Fig. 65c

Fig. 65b

Fig. 65a

ULNAR VARIANCE: all these are PA views made with

the elbow at the shoulder height, the acceptable posi-

tion to measure ulnar variance, which is the relative

length of the ulna compared to the radius. Recognition

of this position at radiography is supported by the fact

that the extensor carpi ulnaris (ECU) groove (arrows) is

radial to the midportion of the ulnar styloid. These

views show a) ulnar neutral variance, b) ulnar negative

variance, and c) ulnar positive variance. See text.



IMPACTION SYNDROME, ULNOCARPAL

ULNOCARPAL IMPACTION SYNDROME see IMPACTIONSYNDROME, ULNOCARPAL

ULNOCARPAL IMPINGEMENT see IMPACTION SYNDROME, ULNO CARPAL

ULNOVOLAR CARPAL PROJECTION see SEMISUPINATEDOBLIQUE VIEW

UNBONDED see DISSOCIATION

UNLINKED see DISSOCIATION

VENTRAL see VOLAR, PALMAR

VENTRAL INTERCALATED SEGMENT(AL) INSTABILITY (VISI)see VOLAR INTERCALATED SEGMENT INSTABILITY

VOLAR

SYNONYMS: anterior, palmar, ventral

CLINICAL: the opposite side of the wrist from the dorsum; the por-tion of the wrist structures covered by the skin of the proximal palmand the distal, palmar skin of the forearm

RADIOLOGIC: the portion of the wrist including the skeletal pillars(tuberosity of the scaphoid and trapezium, pisiform, hook ofhamate) and the soft tissue structures adjacent to them

COMMENTS: 1) “volar” is an adjective and at the wrist is used toindicate the underside of the wrist or any of its structures. 2) Al-though the term preferred by anatomists is said to be “palmar,” theterm in most common usage among wrist investigators and sur-geons is “volar.” 3) Some wrist experts in the past have not liked thisword because they believed the root of the word “vole” refers to asmall mouse-like rodent. However another wrist expert (James Do-byns) points out that the field mouse or vole is named from theNorwegian “woll” or field, not from the Latin “vol,” which refers tothe palm or sole.



VOLAR CARPAL TRANSLATION see PALMAR RADIOCARPALSUBLUXATION

VOLAR INTERCALATED SEGMENT INSTABILITY (VISI) (FIGURE 66)

SYNONYMS: ventral ISI (VISI), palmar ISI (PISI), volar intercalatedsegmental instability (VISI), flexion instability

CLINICAL: a general class of symptomatic carpal instability charac-terized by pathologic volar flexion of the lunate, with or without asimilar posture of the other proximal carpal row bones, and asyn-chronous movement of the proximal and distal carpal rows. Also, seeCIND-VISI and CID-VISI and comments #1 and #6.

RADIOLOGIC: on a neutral (zero) lateral radiograph, the radiolunateangle is >20°, and/or the capitolunate angle is >30°, and/or thescapholunate angle is <30°. To recognize abnormal motion within theproximal carpal row, fluoroscopic evaluation in the lateral positionwith flexion and extension and in the PA position with radial and ul-nar deviation allows recognition if the lunate moves smoothly (syn-chronously) with the scaphoid and triquetrum or if one or more ofthese three bones move(s) in a nonsmooth (asynchronous) manner.

COMMENTS: 1) occasional patients with “ligamentous laxity” havea configuration of VISI (CIND-VISI) that is asymptomatic, com-

Fig. 66a

VOLAR INTERCALATED SEGMENT INSTABILITY (VISI): a) lateral

view: the lunate is tilted palmarly as is the scaphoid to provide a

decreased scapholunate angle of <30° and a capitolunate angle to

be abnormally increased to >30°. The capitate is also slightly sub-

luxed ventrally. b) Diagrams of the wrist with VISI configuration in the

lateral position from left to right show that, with VISI, both the

scaphoid and lunate tilt (both curved arrows pointing toward the

palm) toward the palm. As that happens, with time, the proximal end

of the capitate tends to sublux ventrally (small arrow). Such change

in alignment produces the typical decreased scapholunate angle

of <30°, and/or an increased capitolunate angle of >30°. S =

scaphoid, C = capitate, and L = lunate axes. (Reprinted with per-



Fig. 66b



monly is present bilaterally, and is associated with grossly normal in-tercarpal motion. Many females have RL angles >30°. For VISI to bepathologic, there must be a difference between the normal and ab-normal sides. Also, VISI should have abnormal intercarpal motion.On lateral views of the wrist, the failure of the mid axis of the capitateto flex and extend with respect to the mid axis of the lunate, and themid axis of the lunate to flex and extend with respect to the mid axisof the radius with flexion and extension of the wrist, respectively,may be used as an indicator of abnormal intercarpal motion (refer-ence #7). The VISI that is a normal variant usually has normal andsymmetric intercarpal motion, contrary to that of the VISI that maybe a true symptomatic malalignment. 2) Since the lunate is abnor-mally flexed in each instance, its measurements in relation to the ra-dius proximally and the capitate distally are the angles recorded. 3) Itis important to differentiate between the three types of VISI, sincetheir prognosis and types of treatment vary. When lunate flexiononly is emphasized, it is easy to confuse the VISIs. “IS” stands for “in-tercalated segment” and may therefore refer to the situation whereinthe entire proximal carpal row (PCR) may be in abnormal flexion(CIND-VISI), the lunate and scaphoid may be in abnormal flexionwith the triquetrum in neutral or extension (CID-VISI), or rarely thelunate alone may be in abnormal flexion with both the scaphoid andtriquetrum in neutral or extension (CIC-VISI). Differentiation be-tween these various types of VISI is important because the treatmentvaries with each one. 4) When the entire PCR deforms as a unit, thismay be either from true malalignment, adaptive carpus, or extrinsicligament deficiency (dorsally at radiocarpal [RC] level and/or volar atthe midcarpal [MC] level, or both). 5) This term does not separatefixed from dynamic instability (malalignment). 6) VISI malalign-ment may not reflect a true instability even if the malalignment is a

pathologic or a congenital condition, when the malalignment is “sta-ble” and cannot be reduced, and is not truly “unstable.”


REFERENCES:1. see DORSAL INTERCALATED SEGMENTAL INSTABILITY (DISI)

2. Lichtman DM, Schneider JR, Swafford AR, Mack GR. Ulnar midcarpal instability—clinical and laboratory analysis. J Hand Surg [Am]. 1981;6:515-23.

3. Reagan DS, Linscheid RL, Dobyns JH. Lunotriquetral sprains. J Hand Surg [Am]. 1984;9:502-14.

4. Horii E, Garcia-Elias M, An KN, Bishop AT, Cooney WP, Linscheid RL, Chao EY. A kinematic study of luno-triquetral dissociations. J Hand Surg [Am]. 1991;16:355-62.

5. Taleisnik J. The wrist. New York: Churchill Livingstone; 1985. Medial carpal in-stability; p 281-303.


7. Gilula LA, Weeks PM. Post-traumatic ligamentous instabilities of the wrist. Radiology. 1978;129:641-51.

WATSON MANEUVER/TEST see SCAPHOID STRESS TEST

ZERO LATERAL POSITION see NEUTRAL LATERAL VIEW

ZERO POSITION see ANATOMIC NEUTRAL

ZERO POSTEROANTERIOR POSITION see NEUTRAL POSTEROANTERIOR VIEW

ZIGZAG COLLAPSE see COLLAPSE DEFORMITY, CARPAL COLLAPSE, and CONCERTINA DEFORMITY

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