Rankin et al.The Journal

HAND

22. Parkinson RW, Hodgkinson JP, Hargadon EJ. Symptom..atic non-union of the carpal scaphoid: Matti-Russe bone:grafting versus Herbert screw fixation. Injury’1989;20:164-6.

23. Parren SM, Huggler A, Russenberger M, et al. The re-action of cortical bone to compression. Acta OrthopScand 1969;125:19-27.

24. Milford L. The hand. In: Crenshaw AH, ed. Cambell’.operative orthopaedics. 7th ed. St. Louis: CV1987:207-15.

25. McLaughlin HL. Fracture of the carpal navicular (scaph-,oid) bone. J Bone Joint Surg 1954;36A:765-74.

26. Moran R, Curtin J. Scaphoid fractures treated byscrew fixation. J HAND SURG 1988;13B:453-5.

Augmented external fixation of unstable distalradius fractures :

The technique of "augmentation" of external fixation employs the use of percutaneous Kirschnerwires to secure the radial styloid fragment as a lateral buttress, elevate and fix in place thedepressed lunate fossa fragment, and, when necessary, add support to the elevated articularsurface by means of subarticular bone grafting. A series of 51 cases of comminuted, unstableintraarticular distal radius fractures has been managed using this technique. Detailed evaluationhas demonstrated precise articular reconstitution with an overall satisfactory result rate of 92 %.(J HAND SURG 1991;16A:1010-6.)

William H. Seitz, Jr., MD, Avrum I. F’roimson, MD, Robert Leb, MD, and

Jeffrey D. Shapiro, MD, Cleveland, OMo

ExPerience in the management of unsta-

ble distal radius fractures using the principle of liga-mentotaxis through external fixation has undergone arecent evolutioma-5 Improved surgical technique and fix-ation devices have been reflected in improved resultswith fewer complications.I, 6, 7 However, careful eval-uation of radiographic results, even in those patientswith acceptable clinical outcomes, has led to the ob-servation that well-reduced fractures have the potentialt6 undergo late displacement and/or collapse with loss

From the Hand and Upper Extremity Surgery Clinics, Departmentof Orthopaedic Surgery, The Mt. Sinai Medical Center, Cleveland,Ohio,

Received for publication June 29, 1990; accepted in revised formOct. 25, 1990.

No benefits in any form have been received or will be received froma commercial party related directly or indirectly to the subject ofthis article.

Reprint requests: William H. Seitz, Jr., MD, Department of Ortho-paedic Surgery, The Mt. Sinai Medical Center, One Mt. Sinai Dr.,Cleveland, OH 44106.

3/1/26995

of the initial articular congruity (Fig. 1). Recognitionof this potential for displacement has led to the evolutionof the technique for augmentation of external fixationwith percutaneous Kirschner (K-) wire fixation

major articular fragments and, when necessary, sup-portive bone grafting to maintain adequate art-~cular el-evation (Fig. 2).

Materials and methods

Data. Fifty-one patients; ~ with an age range from 18to 98 years (average age, 50 years) have been treatedby augmented external fixation and followed-up for 1 1 !

to 4 years after operation (average, 2.5 years). All pa-tients had sustained unstable intraarticular distal radiusfractures consisting of a major radial styloid fragment,lunate fossa fragment, and significant dorsal and/orvolar comminution (Fig. 1). Nine (16%) of the tients underwent bone grafting (Table I). .... ~"~i

Surgical technique. All patients had either general" i

endotracheal, or axillary block anesthesia. A "limitedopen surgical approach" was used for insertion of fix- :! iator pins in the ~adius and proximal aspect of the index

1010 THE JOURNAL OF HAND SURGERY

Journal 16A, No. 61991 Augmented external fixation of unstable fractures 1011

:V Mosby

.at (scaph.:4.

,gnitionolutionixationof the

¢, sup-alar ,~l-

Fig. 1. Musculotendinous forces acting across the wrist tend~ ~!~; .~i:~ to cause the radial styloid fragment to displace laterally andom 18

reated ~:~:i the lunate fossa fragment to depress.

for 1dl pa- and middle metacarpals? This technique employs tworadiusment,nd/~ril pa-

neral,mited~f fix-index

1-inch incisions, one centered approximately 10 cmto the radial styloid over the radial aspect of

the forearm. The interval between the extensor carpiradialis longus and brachioradialis is identified. Theradial sensory nerve is identified and carefully retracted

these two tendons from underthe brach]o{adialis. Direct visualization of the radiusallows central insertion of the pins after predrilling.This avoids eccentric drill placement and/or multiple

]~’ig. 2. After restoration of length and alignment by the ex-ternal fixator, Kirschner wires have been percutaneously in-serted under fluoroscopic control to "lock, in" the radial styloidbuttress and support the elevated lu~aate fossa fragment.

drill passes, which can result in significant weakeningof the bone and pin loosening.7 Distal pin insertion,liikewise, is made under direct vision guided by imageintensification, placing the proximal pin through themetaphyseal bases of the index and middle metacarpalsand the distal pin through the shaft of the index meta-carpal alone. This provides pin purchase in a total ofsix cortices while avoiding violation of the interosseouscompartments. Once pin insertion has been done, theexternal fixation device itself is applied and then the

1012 Seitz et al.The Journal of

HAND SURGERY

Fig. 3. Patient 24: Satisfactory result. A, Unstable iintraarticular distal radius fracture in a 60-year-old man. B-C, External fixation has been augmented using radial styloid and subarticular lunatefossa pins with subarticular supportive bone graft. Kirschner wires have secured a concomitantscaphoid fracture.

"initial fracture reduction is obtained, again under imageintensification control. This initial reduction achievesrestoratibn bf overall length and radial tilt. At this pointan additional 2 mm of traction is applied through thedevice, resulting in an increase of 2 mm in the measuredjoint space of the radioscapholunate articulation com-pared to the midcarpal articulation. This traction applies

tension across the dorsal and palmar radioscapholunateligaments, keeping them taut during the period of im-mobilization (allowing rapid return of flexion/exten-sion on removal of the device).

With the radial styloid realigned to the shaft,a smooth 0.062 K-wire is inserted percutaneously andobliquely from the tip of the radial styloid across the

Vol. 16A, No. 6November 1991

Augmented external fixation of unstable fractures 1013

Fig. 3 (Cont’d). D-E, Two years after operation the patient has a normal wrist both functionally

and radiographically.

1014 Seitz et al.The Journal

HAND SURGERY

Fig. 4. Patient 22: Poor result. A, An unstable intraarticular distal radius fracture in the left wristof a 44-year-old man. B, Augmented extemat fixation has not achieved an anatomic reduction.The radial styloid fragment has not been adequately aligned and the lunate fossa fragment has beenover-reduced, creating an incongruous articular surthce and narrowing of the distal radioulnar joint.No bone graft was used despite 7 ram initial shortening. C, One year after operation the patienthas a narrow painful joint with degenerative changes at both the radiocarpal and distal radioulnarjoint. He has subsequently had a wrist arthrodesis.

major fracture site and secured in the ulnar cortex ofthe shaft. The radial styloid thus secured acts as a but-tress. A free 0.062 K-wire is inserted percutaneouslyunder image intensification control dorsally. It is usedto elevate the lunate fossa articular fragment so that itis precisely congruent with the remainder of the distal

iradial articular surface. With this fragment in the re-duced position, a third smooth K-wire is inserted per-cutaneously under image intensification control trans-versely from the radial aspect of the styloid fragmentdirectly underneath the subchondral bone of the elevated"die-punch" fragment (Fig. 2). Additional subchondralK-wires may be percutaneously added as needed de-pending on the degree of comminution. Permanentx-ray films are then obtained to evaluate supportivebone stock beneath the elevated fragments. If a signif-icant lucency is encountered (usually seen with initialdepression of 5 mm or more), bone grafting is done

¯ through a dorsal approach. Final x-ray films are thenobtained to ensure congruence of the radiocarpal anddistal radioulnar joints) When this is confirmed, a bulkysoft compression dressing is applied and immediatepostoperative rehabilitation commences.

Results

All patients were evaluated for active range of mo-te!on, grip strength, pain, function, and by careful ra-diographic analysis. A satisfactory result required ra-diographic restoration of anatomy measured by radiallength, tilt, and articular congruity. Additionally neededwere range of motion and grip strength within 80~ ofnormal, freedom from pain, and functional use of thewrist. An unsatisfactory grade resulted from failure toachieve 80% of normalcy in al!. categories.

Forty-seven (92%) patients ~had satisfactory resultsand 4 ~had unacceptable results. One was due to inad-equate initial reduction and fixation and subsequent pro-gressive collapse resulting in an incongruous painfulwrist joint (Fig. 4). One patient had reflex sympatheticdystrophy. Two patients demonstrated diminis.hed gripstrength and ulnar-sided wrist pain. Complications wereconfined to the case of reflex sympathetic dystrophyand articular collapse due to unrecognized inadequatereduction and fixation. Minor complications includedfive patients with superficial pin tract infection. Allpatients responded to oral antibiotics without need forpin removal. At the time of device removal, 11 (6%)

Vol. 16A, No. 6November 1991 Augmented external fixation of ~nstable fractures 1015

204 fixator pins were loose enough to be removed

by hand, but in no case did loose pins result in loss offixation. There were no fractures through the pin sites,

no injuries of the radial sensory nerve or tendons of thef,~reann, no cases of intrinsic contracture, and no deepinfections.

Discussion

Successful management of the unstable intraarticular

distal radius fracture with external fixation requires pre-cise restoration of joint congruence and skeletal align-ment.8.9 This technique has, however, been reported tocarry a high complication rate. 1° Evolution of the sur-

gical technique from "pins-in-plaster" and improved~~xation devices has helped reduce treatment-related~:omplications. 1-3, 5.11

The evolving rationale for augmentation of externalfixation in the management of unstable distal radiusfractures recognizes that during treatment late settlingof initially well-reduced fractures can and does occur.This rationale has been supported by cadaver studies inour laboratory whereby "induced" unstable distal radiusfractures with major radial styloid and "die-punch" frag-ments have been artificially created. Despite support ofan external fixation device, forces created by muscle-:endon units traversing the wrist tend to cause a lat-eral/rotational displacement of the radial styloid frag-ment and impaction of the lunate fossa fragment. Sim-ple addition of K-wires, although only "internal su-tures," is adequate to resist these forces. This has been

borne out clinically with a high rate of satisfactory

results and specifically with an extremely high radio-graphic rating. Our ability to adequately manage thechallenge of the unstable distal radius fracture lies in

our ability to restore anatomy while limiting ourtreatment-related complications. Our past experiencehas demonstrated that a limited open surgical approachcombined with pins of adequate size can avoid bendingand breakage and provide appropriate bone purchase;

fixation to the radial shaft and six cortices of the indexand middle metacarpals allows pronation and supinationwhile helping to minimize the complications related tothe pin/bone interface. 7 An external fixation device thatallows pin insertion before fracture reduction while pro-viding adequate stability and clear fracture visualiza-tion in all planes simplifies the surgical technique and

therefore minimizes potential device-related compli-cations.6

Although a fairly close anatomic restoration can beachieved through closed reduction, maintenance of thisreduction can be lost without additional internal sup-

Table I. Data on fifty patients treated withaugmented external fixation

I IWeeks in Follow-upBone graftfixator Result (YR)Number Age Sex (Y or N)

1 76 M N 5 S2 42 M N 5 S3 26 M Y 6 S4 26 M N 6 S5 72 F N 6 S6 18 F N 6 S7 38 M N 5 S8 72 F N 5 S9 35 M Y 7 S

10 46 F N 5 S11 71 F N 6 S12 60 F N 5 S13 45 F N 5 S14 66 F N 5 S15 67 F N 5 S16 73 F N 6 S17 31 F Y 5 S18 58 F N 5 S19 80 F Y 5 S20 24 M N 5 S21 22 M N 6 S22 44 M N 6 U23 61 F N 6 S24 32 F Y 6 S25 51 F N 6 S26 41 M N 6 S27 .39 M N 6 S28 40 F N 5 S29 67 F N 5 S30 ~ 70 F Y 5 S31 24 F N 8 U32 65 F N 6 S33 22 M N 6 S34 38 M N 6 S35 34 M N 6 S36 42 F N 6 S37 33 M N 5 S38 49 M N 5 S39 71 F N 6 ’.~ S40 19 M N 6 S41 56 F Y 5 U42 98 F Y 5 S43 42 F N 5 S44 53 F N 6 U45 51 M N 5 S46 36 M N 5 S47 71 F N 6 S48 69 F N 5 S49 69 F N 5 S50 52 F N 6 S51 60 M Y 8 S

2344444444333333222222333332333221121111112222

.22232

S, Satisfactory; U, unsatisfactory.

1016 Seitz et al.

port. Once fixed in place with a K-wire, the major radialstyloid fragment acts as a buttress for the lunate fossafragment and the smaller periarticular fragments of dor-sal and/or anterior comminution. Use of a K-wire asa "joystick" to elevate a depressed lunate fossa fragmentis effective in restoring a congruent transition fromscaphoid fossa to lunate fossa of the distal radial artic-ular surface. Need to elevate the lunate fossa 5 mm ormore after radial styloid reduction and fixation has dem-onstrated a void of metaphyseal bone. This requires asupportive bone graft behind the transverse subarticularKirschner wire. Addition of this limited internal fixationand bone graft in appropriate cases has not resulted inan increased complication rate, has provided superior

overall results, and has demonstrated a maintenance ofarticular congruity by radiographic assessment. The im-portance of immediate postoperative hand rehabilitationand patient education in activities of daily living and

in pin-site care cannot be overstated.

REFERENCES

1. Kongsholm J, Olerud C. Plaster cast versus external fix-ation for unstable intraarticular Colles’ fractures. ClinOrthop 1989;241:57.

2. Andrianne Y, Donkerwolcke M, Hinsenkamp M, et al.Hoffman external fixation of fractures of the radius andulna. A prospective study of 53 patients. Orthopaedics1984;7:845.

The Journal ofHAND SURGERY

3. Cooney WP. External fixation of distal radius fractures.Clin Orthop 1983;180:44.- "~

4. Seitz WH, Flatow EL, Putnam MD, Dick HM.’The treat-ment of unstable distal radius fractures by a techniqueof external fixation utilizing a limited open approach.Orthop Trans 1986;10:575.

5. Seitz WH, Putnam MD, Dick MD. The limited opensurgical approach for external fixation of unstable distalradius fractures. J HAND S~JRG 1990;15A:288-93.

6. Seitz WH, Froimson AI. Reduction of treatment-relatedcomplications in the external fixation of unstable distalradius fractures. Orthop Trans 1989;13:567-8.

7. Seitz WH, Froimson AI, Brooks DB, et al. Biomechan-ical analysis of pin placement and pin size for externalfixation of distal radius fractures. Clin Orthop 1990;251:207-12.

8. Jupiter JB, Knirk JL. Intra-articular fractures of the distalend of the radius in young adults. J Bone Joint Surg1986;68A:647.

9. Melone CP. Articular fractures of the distal radius. ClinOrthop North Am 1984;15:217.

10. Weber SC, Szabo RM. The severely cornminuted distalradius fractures as an unsolved problem: complicationsassociated with external fixation and pins-and-plastertechnique. J HAND SURG 1986;11A:157.

I 1. Green DP. Pins and plaster treatment of comminutedfractures of the distal end of the radius. J Bone JointSurg 1975;57A:304.