Download pdf - Surgical Exposures of the Humerus - Orthobulletsupload.orthobullets.com/journalclub/free_pdf/17148623_17148623.pdfSurgical Exposures of the Humerus The neurovascular and muscular anatomy

Surgical Exposuresof the Humerus

The neurovascular and muscular anatomy about the humerusprecludes the use of a truly “safe” fully extensile approach.Working around a spiraling radial nerve at the posterior midshaftrequires either a transmuscular dissection or a triceps-avoidingparamuscular technique. To gain maximal exposure, the radialnerve must be mobilized at the spiral groove. For exposure of onlythe proximal humeral shaft, many surgeons prefer the anterolateralapproach because it uses the internervous plane between theaxillary and deltoid nerves proximally and the radial andmusculocutaneous nerves distally. Proximally, the deltopectoralapproach to the shoulder continues to be the most widely used.However, the lateral deltoid-splitting approach is a viable, lessinvasive approach for both rotator cuff repair and fixation of valgus-impacted proximal humeral fractures. Distally, intra-articularexposure is dependent on triceps mobilization, either by olecranonosteotomy or triceps release; this exposure can be coupled witheither a triceps-splitting or a paratricipital approach for proximalextension.

Surgical approaches to the hu-merus are designed to circumnav-

igate the complicated neural anat-omy of the shoulder and brachium.These approaches are frequently usedfor the spectrum of upper extremityprocedures, from fracture fixation toarthroplasty. The humerus can be di-vided into three zones: proximalhumerus, humeral shaft, and distalhumerus. There are indications, ad-vantages, and disadvantages to theclassic surgical exposures to the hu-merus as well as to some of the mostrecently developed more extensileexposures. Of paramount importanceis the neurovascular anatomy of thebrachium (Table 1). Proximally, thecircumflex humeral vessels and theaxillary nerve divide the humerus atthe surgical neck. Distally, the radialand ulnar nerves travel in circuitous

paths, crossing intermuscular septae.Techniques for avoiding injury tothese structures while providing am-ple visualization are compiled fromthe literature and from our experi-ence.

Patient positioning varies basedon both the involved region of thehumerus and the desired exposure.For the proximal humerus, the pa-tient may be positioned in the beachchair, lateral, supine, or prone posi-tion. Dorsal approaches to the mid-shaft and distal humerus include thelateral decubitus or prone positionwith the arm over a post, or the su-pine position with the arm restingacross the patient’s chest on a bol-ster. The supine position with thearm on a hand table may be used foranterior approaches to the midshaftand distal humerus.

Dan A. Zlotolow, MD

Louis W. Catalano III, MD

O. Alton Barron, MD

Steven Z. Glickel, MD

Dr. Zlotolow is Assistant Professor ofOrthopaedics, University of MarylandSchool of Medicine, Baltimore, MD. Dr.Catalano is Assistant Clinical Professorof Orthopaedic Surgery, ColumbiaCollege of Physicians and Surgeons,New York, NY, and Attending Physician,C. V. Starr Hand Surgery Center, St.Luke’s–Roosevelt Hospital Center, NewYork. Dr. Barron is Assistant ClinicalProfessor of Orthopaedic Surgery,Columbia College of Physicians andSurgeons, New York, and AttendingPhysician, C. V. Starr Hand SurgeryCenter, St. Luke’s–Roosevelt HospitalCenter, New York. Dr. Glickel isAssociate Clinical Professor ofOrthopaedic Surgery, Columbia Collegeof Physicians and Surgeons, New York,and Attending Physician, C. V. StarrHand Surgery Center, St. Luke’s–Roosevelt Hospital Center, New York.

None of the following authors or thedepartments with which they areaffiliated has received anything of valuefrom or owns stock in a commercialcompany or institution related directly orindirectly to the subject of this article:Dr. Zlotolow, Dr. Catalano, Dr. Barron,and Dr. Glickel.

Reprint requests: Dr. Zlotolow,Department of Orthopaedics, KernanHospital, 2200 Kernan Drive, Suite1154, Baltimore, MD 21207.

J Am Acad Orthop Surg 2006;14:754-765

Copyright 2006 by the AmericanAcademy of Orthopaedic Surgeons.

754 Journal of the American Academy of Orthopaedic Surgeons

Anatomy

The axillary nerve is a continuationof the posterior cord. The nerve trav-els anterior to the subscapularis,wraps around the surgical neck ofthe humerus, and passes through thequadrangular space to innervate the

teres minor and deltoid muscles (Fig-ure 1). The nerve lies between 4.3and 7.4 cm from the lateral edge ofthe acromion.1 After entering theposterior third of the deltoid, thenerve travels along the deep deltoidfascia to innervate the middle andanterior thirds of the deltoid sequen-

tially. The nerve to each head of thedeltoid does not branch until itcrosses each raphe.

The radial nerve is the other ter-minal branch of the posterior cord.This nerve begins anteromediallyand travels along the subscapularisto join with the deep brachial artery

Table 1

Surgical Exposures of the Humerus

Location Procedure Clinical Example Surgical ApproachConcerns and

Limitations

Proximal Total shoulderarthroplasty

Conventional or reverseprosthesis

Deltopectoral Axillary nerve, anteriorhumeral circumflexartery

ORIF of the proximalhumerus

Three- or four-partfractures requiringopen reduction

Deltopectoral Axillary nerve, deltoidinsertion, anteriorhumeral circumflexartery

Valgus-impacted orisolated greatertuberosity fractures

Deltoid split Axillary nerve, deltoiddetachment

Rotator cuff tear Supra-/infraspinatustear

Deltoid split Axillary nerve, deltoiddetachment

Subscapularis tear Deltopectoral Axillary nerve,musculocutaneousnerve, anterior humeralcircumflex artery

Middle ORIF of humeralfracture

Proximal to mid thirdfracture

Anterolateral Divides the brachialis,lateral antebrachialcutaneous, and radialnerves

All diaphyseal fractures Lateral paratricipital Radial nerve, posteriorantebrachial cutaneousnerve

Distal third fracture Triceps split Radial nerve, lessextensile proximally

Distal ORIF of intercondylarfracture

Simple fracture requiringbicolumnar fixation

Medial and lateralparatricipital

Ulnar and radial nerves,poor intra-articularvisualization

Intra-articular fracturewithout anteriorcomminution

Medial triceps reflection Ulnar nerve,tendon-to-bone healing

Intra-articular fracturewith anteriorcomminution

Olecranon osteotomy Ulnar and radial nerves,olecranon nonunion

Elbow arthroplasty Implant or interpositionarthroplasty

Medial triceps reflection Ulnar nerve,tendon-to-bone healing

Extensile ORIF of segmentalhumeral fracture

Diaphyseal and distalintra-articular fracture

Lateral paratricipitalwith lateral reflection

Radial and axillarynerves, tendon-to-bonehealing, anconeus

Proximal humeralfracture with proximalto mid third shaft

Deltopectoral withanterolateral

Radial, axillary, andlateral antebrachialcutaneous nerves

ORIF = open reduction and internal fixation

Dan A. Zlotolow, MD, et al

Volume 14, Number 13, December 2006 755

at the triangular interval. Beginning97 to 142 mm from the lateral acro-mion, the nerve and artery then trav-el along the spiral groove, separatingthe medial and lateral heads of thetriceps. The nerve exits the spiralgroove 101 to 148 mm proximal tothe lateral epicondyle.2 As the nervepasses into the anterior brachiumthrough the lateral intermuscularseptum, the nerve is, on average,10 cm from the distal articular sur-face of the elbow but never closerthan 7.5 cm.3 Distally, the radialnerve travels deep between the bra-chialis and brachioradialis musclesbefore bifurcating at the level of theradiocapitellar joint. Hence, the radi-al nerve originates anteromedially,

courses posteriorly along the humer-us, and emerges anterolaterally inthe distal brachium.

The ulnar nerve arises from themedial cord and travels anterior to themedial intermuscular septum (Figure1, B). At the arcade of Struthers, ap-proximately 8 cm from the medial epi-condyle, the nerve crosses into theposterior compartment4 (Figure 1, A).It then courses posterior to the inter-muscular septum and the medial epi-condyle to enter the cubital tunnel.The ulnar nerve gives off an articularbranch to the elbow joint that can besacrificed during surgical exposure.Distally, the nerve passes into the an-terior forearm between the two headsof the flexor carpi ulnaris.

Although rarely encountered insurgical exposures to the humerus,the brachial artery and median nervewarrant mention. The median nervereceives contributions from the me-dial and lateral cords and travels justmedial to the brachial artery alongthe anterior surface of the medial in-termuscular septum. At the elbow,the median nerve and the brachialartery can be found between the pro-nator teres muscle and the bicepstendon.

The deltoid enshrouds the proxi-mal humerus and is divided intothree heads by two fibrous raphes.The anterior, middle, and posteriorheads originate from the distal clav-icle, lateral acromion, and scapular

Figure 1

A, Posterior view of the neural anatomy of the brachium with reference measurements (in cm) from prominent anatomiclandmarks. The area between the axillary nerve and the spiral groove is the proximal safe zone of the posterior humerus. Thedistal safe zone is distal to the spiral groove. B, Anterior view of the shoulder. Note the relationship of the axillary nerve and theanterior circumflex humeral artery to the inferior margin of the subscapularis muscle. During the deltopectoral approach, the“three sisters” (anterior humeral circumflex artery and its two venous communicantes) are often ligated separately to minimizeblood loss and gain adequate exposure of the humeral metaphysis.



spine, respectively. These three headsconverge into a broad, 4-cm–widetendinous insertion along the lateralhumerus, approximately 9 to 13 cmdistal to the lateral acromion. Theanterior head originates from boththe anterior acromion and the clav-icle and forms a discrete insertion,constituting approximately one fifththe width of the deltoid insertion.Therefore, partial anterior deltoid re-lease of more than one fifth of the in-sertion, frequently performed duringplate fixation, completely detachesthe anterior head of the deltoid.5 Theclinical sequelae of anterior deltoiddetachment is unknown.

In the brachium, the most oftenencountered muscles are the tricepsand the brachialis. The long head ofthe triceps originates from the infe-rior glenoid tubercle, the lateral headfrom the humeral shaft superolater-al to the spiral groove, and the medi-al head inferomedial to the spiralgroove. The lateral and long headsare superficial, with a visible, oftenpalpable, cleft proximally, terminat-ing in a common tendon. The medi-al head is deep and is accessible bydividing the long and lateral heads ofthe triceps. Innervation is providedby branches of the radial nerve. Theradial nerve then passes through thelateral intermuscular septum to in-nervate the lateral third of the bra-chialis. The medial two thirds of thebrachialis muscle and the remainderof the anterior compartment are in-nervated by the musculocutaneousnerve.

Proximal Humerus

Anterior ApproachThe deltopectoral approach is the

workhorse exposure for the proximalhumerus. This approach developsthe internervous plane between thedeltoid (axillary nerve) and the pec-toralis major (medial and lateral pec-toral nerves). The cephalic vein isthe landmark for this interval. Thedeltopectoral approach is useful foropen reduction and internal fixation

of a proximal humeral fracture,shoulder arthroplasty, anterior cap-sular shift, and subscapularis repair.We prefer this approach for shoulderarthroplasty and for plate-and-screwfixation of proximal humeral frac-tures because it affords greater visu-alization than does the lateral ap-proach.

The axillary nerve should be pal-pated as it passes inferior to the sub-scapularis and the inferior capsule,and it should be protected through-out the procedure. External rotationof the shoulder during subscapularisrelease moves the dissection awayfrom the axillary nerve and decreas-es tension on the nerve. Dissectionmedial to the conjoined tendonshould be avoided because it placesthe musculocutaneous nerve at risk.Care should be taken to isolate andligate the anterior humeral circum-flex artery, along with, if necessary,its two venous communicantes atthe distal margin of the subscapu-laris tendon during the exposure(Figure 1, B). To maintain the bloodsupply to the humeral head, surgicaldissection should not extend to theinferior margin of the subscapularis.A cuff of muscle must be main-tained to protect the anterior humer-al circumflex vessels. Likewise, byreleasing the subscapularis medial toits tendinous insertion, the arcuateartery is not sacrificed at the point atwhich it enters the humeral headalong the lateral border of the bicip-ital groove.6,7

When a greater exposure of thelateral humeral shaft is needed, lessthan one fifth of the anterior deltoidinsertion can be released.5 Distal ex-tension may be accomplished via theanterolateral approach to the hu-merus.

Lateral ApproachThe second most common ap-

proach to the proximal humerus in-volves splitting the deltoid muscle.A split can be performed most easi-ly through either raphe. The anteri-or raphe allows better access to the

supraspinatus insertion and is opti-mal for antegrade humeral nailing.We prefer this approach for the fixa-tion of two-part greater tuberosityfractures or other proximal humeralfractures amenable to treatmentwith a combination of suture fixa-tion and/or intramedullary devices.We also use this approach to managevalgus impacted three- and four-partfractures (Figure 2). The more poste-rior rotator cuff tear can be accessedvia the posterior raphe. A stay sutureis placed in the distal-most apex ofthe split to prevent unwanted prop-agation and, thus, injury to the axil-lary nerve. For greater visualization,a portion of the deltoid can be re-leased from the anterolateral acro-mion. At the time of closure, thecrescentic deltoid origin should berepaired to the lateral acromionthrough small bone tunnels madewith a towel clamp.

The deltopectoral and deltoid-splitting approaches may be com-bined to provide an extensile ap-proach to the proximal humeruswithout risking denervation of thedeltoid itself. This dual approach ishelpful for concurrent subscapularisand posterosuperior rotator cuff tearsas well as for anterior shoulder stabi-lization procedures with associatedrotator cuff tears.8

Traditionally, the deltoid-splittingapproach has been limited by thecourse of the axillary nerve to within5 cm distal to the acromion. A re-cently described technique exploitsthe fact that the axillary nerve doesnot branch to innervate each deltoidhead before crossing each raphe.9 Ex-tending the deltoid split through theraphe after protecting the main axil-lary trunk allows a more distal expo-sure of the proximal humerus with-out denervating the anterior deltoid9

(Figure 3). This approach providessufficient visualization to performplate-and-screw fixation of proximalhumeral fractures, with the plateplaced deep to the isolated and pro-tected axillary nerve and circumflexarteries.



Posterior ApproachPosterior approaches to the prox-

imal humerus are less commonly per-formed because of the difficulty of theexposure and the infrequency of in-dications. The most common indica-tions are posterior glenohumeral in-stability and tumor surgery. Thepatient is usually placed in either abeach chair or lateral position, withthe arm draped free to allow unre-stricted mobility of the glenohumeraljoint. To allow release of the posteriordeltoid origin from the scapular spine,the incision is made at a 45° angle tothe scapular spine, halfway betweenthe spine and the humerus (Figure 4).The teres minor is then retracted withthe deltoid, along with their commonneurovascular pedicle, the axillarynerve, and the posterior humeral cir-cumflex artery. The plane betweenthe infraspinatus and teres minor canbe difficult to identify. It is best seencloser to the tendinous insertion atthe level of the joint with the shoul-der held in internal rotation. Sweep-ing the fascia off the two muscle bel-lies of the infraspinatus and the onemuscle belly of the teres minor oftenreveals a fat stripe between the in-

fraspinatus and teres minor. Occa-sionally, the tubercle of the teres mi-nor can be found at the superiormargin of the teres minor insertion.

Exposure of the posterior gleno-humeral joint capsule can beachieved by retracting the supra-scapular nerve–innervated infraspi-natus muscle superiorly. When fur-ther capsular exposure is neededsuperiorly, the infraspinatus tendonmay be released 1 cm from its inser-tion onto the greater tuberosity andreflected medially. This additionalexposure allows greater mobiliza-tion of the infraspinatus, potentiallyplacing undue tension on the supras-capular nerve as it enters the in-fraspinatus muscle just distal to thespinoglenoid notch of the scapula.10

One limitation of this approach isthe lengthy deltoid detachment re-quired. The posterior approach isalso limited in that it cannot be ex-tended distally. Thus, it is not rec-ommended for addressing patholog-ic conditions distal to the anatomicneck of the humerus.

For exposure of the proximal hu-merus just distal to the surgicalneck, the lateral head of the triceps

can be reflected medially off the hu-merus to approximately 10 cm fromthe posterior aspects of the acromi-on.2 At the midline of the posteriorhumerus, a safe zone exists proximalto the spiral groove between the ax-illary and radial nerves. With thedeltoid retracted laterally, the prox-imal humeral shaft can be ex-posed.11 This approach can be ex-tended distally to expose the entirehumeral diaphysis by continuing toreflect the triceps medially and ele-vating the radial nerve from the spi-ral groove. This approach allows forplacement of plate-and-screw con-structs spanning the length of the di-aphysis. It is particularly useful forlong oblique or spiral shaft fractureswith proximal extension. Alterna-tively, the dissection can be contin-ued along the lateral margin of theradial nerve as it spirals around thehumerus, across the lateral inter-muscular septum, and between thelateral and middle third of the bra-chialis muscle.12

Humeral Shaft

The spiral groove divides the humer-us nearly in half and prevents so-called safe extensile exposure alongthe entire length of the humerus. Se-lection of surgical approach to thehumeral shaft depends on fracturelocation and surgeon preference.Most commonly, an anterolateralapproach is used for proximal andmiddle third shaft fractures. Distalextension is difficult because the lat-eral antebrachial cutaneous and radi-al nerves converge on the anterolat-eral aspect of the elbow. Theposterior approach can be used forfractures along the entire diaphysisand can be extended distally forintra-articular fractures. Many sur-geons shun this technique, however,because it can require dissection andmobilization of the radial nerve anddeep brachial artery at the midshaft.Among the various trauma surgeons,there is no consensus on which ap-

Figure 2

A, Anteroposterior radiograph demonstrating a valgus impacted three-part proximalhumeral fracture managed with a lateral deltoid-splitting approach withoutdetachment of the deltoid or mobilization of the axillary nerve. B, Anteroposteriorradiograph. The humeral head was disimpacted, and the valgus angulation wascorrected. An Interpore coral spacer (Interpore Cross International, Irvine, CA) wasused to fill the cancellous void. The greater tuberosity was then sutured to thehumeral shaft via heavy nonabsorbable braided sutures threaded through drill holes.



proach is preferable for each seg-ment.

Anterolateral ApproachThe anterolateral approach is a

distal continuation of the deltopec-toral approach. Proximally, the in-ternervous plane between the del-toid and biceps muscles is used.Distally in the brachium, there is notrue internervous plane because thebrachialis receives dual innervationfrom the radial and musculocutane-ous nerves. The anterolateral ap-proach, therefore, splits the brachi-alis muscle along the middle andlateral thirds of the muscle belly.

The lateral portion of the brachialisprotects the radial nerve from retrac-tors placed within the split. Caremust be taken distally not to injurethe lateral antebrachial cutaneousnerve as it exits between the bicepsand brachialis muscles. The radialnerve is likewise at risk from distalextension and must be identified be-tween the brachialis and brachiora-dialis.

Posterior ApproachesPosterior approaches involve ei-

ther mobilizing the triceps from lat-eral to medial (paratricipital) or split-ting the muscle belly along its fibers.

The paratricipital approaches offerseveral advantages over triceps-splitting approaches. Some surgeonsadvocate using these approacheswithout a tourniquet because the ap-proaches exploit relatively bloodlessplanes.13,14 Avoiding injury to the tri-ceps muscle itself also may limit in-tramuscular adhesions and scar for-mation and may, at least in theory,help lessen elbow contracture andimprove postoperative triceps func-tion. By staying outside the muscle,there is less risk of denervating aportion of the triceps or the anco-neus. Moreover, extending the expo-sure proximally and distally can be

Figure 3

Lateral view of the shoulder demonstrating an extendeddeltoid-splitting approach with mobilization of the axillarynerve. The axillary nerve enters each head of the deltoid as asingle trunk, allowing for separation of the anterior and middleheads of the muscle along the anterior raphe withoutdenervation of the anterior head.

Figure 4

Posterior view of the shoulder demonstrating the approachvia the internervous plane between the suprascapular nerve(infraspinatus muscle) and the axillary nerve (teres minor anddeltoid muscles). With the shoulder held in internal rotation,a fat stripe can usually be found between the two muscles atthe level of the joint. The skin incision is oriented 45° fromthe scapular spine, allowing access to the scapular spine fordetachment of the posterior deltoid origin while providingadequate visualization of the joint.



accomplished more easily, particu-larly on the lateral side, by mobiliz-ing the radial nerve and elevating thetriceps off the humerus.

The lateral paratricipital ap-proach uses the tissue plane betweenthe lateral head of the triceps and thelateral intermuscular septum (Figure5). The critical aspect of this ap-proach is identification of the radialnerve as it exits the spiral groove ap-proximately 14 cm proximal to thelateral epicondyle and pierces the in-termuscular septum 10 cm from thearticular surface.3,15 The nerve is iso-lated and mobilized from the spiralgroove, taking care to preserve theposterior antebrachial cutaneousnerve. The posterior antebrachial cu-taneous nerve emerges from the ra-dial nerve as the radial nerve exitsthe spiral groove, and it travels alongthe posterior aspect of the lateral in-

termuscular septum. It is importantnot to confuse the posterior antebra-chial cutaneous nerve, which can berather large, with muscular branch-es to the triceps.

Once the radial nerve and itsbranches are identified and protect-ed, the triceps is elevated subperi-osteally and reflected medially. Theapproach may be extended proximal-ly between the posterior deltoid andthe lateral head of the triceps; it islimited by the axillary nerve. Ap-proximately 94% of the humeral di-aphysis can be exposed with this ap-proach15 (Figure 6). Distally, theapproach can be combined with ole-cranon osteotomy, triceps reflectionoff the olecranon, or a modifiedKocher approach. Another advantageof this technique is that it can beperformed without a tourniquet be-cause it exploits a relatively blood-

less plane. Complete visualization ofthe radial nerve on both sides of theintermuscular septum also is possi-ble with this approach.

The triceps-splitting approachseparates the long head of the tricepsfrom the lateral head superficially toreveal the medial head as it origi-nates from the distal-medial aspectof the spiral groove. The interval be-tween the two superficial heads iseasier to locate proximally, beforethe formation of a common tendon,and is best identified by palpation.The radial nerve, which may lie di-rectly on bone or may be separatedfrom the humerus by several milli-meters of the medial head of the tri-ceps muscle, can be mobilized to al-low a plate to be slid beneath it.Without mobilization of the radialnerve, only the distal 55% of the hu-meral shaft can be exposed. Withmobilization of the radial nerve, thedistal 76% of the humeral shaft isaccessible.15 Distally, plating is lim-ited not by the exposure but by en-croachment of the plate across theolecranon fossa. Proximally, the tri-ceps becomes difficult to split, thuslimiting an extensile exposure (Fig-ure 7). A tourniquet may be used forthe initial exposure; significantbleeding may be encountered on re-lease of the tourniquet.

Distal Humerus

Approaches to the distal humerus al-low exposure distal to the spiralgroove, with a “safe zone” of 10 cmfrom the elbow joint.2 Unlike theknee, where the patella and its at-tached extensor mechanism can bemobilized for visualization of thejoint surfaces, the olecranon and tri-ceps tendon are fixed, thus limitingdirect visualization of the elbowjoint. Multiple exposures to the dis-tal humerus have been described toaddress this limitation. These expo-sures can be divided into two catego-ries: procedures that detach the ex-tensor mechanism and those thatmobilize it. In general, detachment

Figure 5

A, Anterposterior view of a periprosthetic mid diaphyseal humeral shaft fracture.B, A lateral paratricipital approach was used to gain access to the entire humeralshaft. The deltoid (D) limits exposure proximally, and the triceps (T) is reflectedmedially. A fixed-angle plate with proximal cables was used to secure the fractureand contain the two fibular strut grafts. The radial nerve (R) and profunda brachiiartery (A) can be seen overlying the plate. C, Six months postoperatively, thefracture is healed, with maintenance of reduction and incorporation of the fibulargrafts. An anterolateral approach was not selected for this fracture because it limitsdistal plate placement and does not allow direct visualization or mobilization of theradial nerve for placement of circumferential cables. Blind cable placement from ananterior exposure at the level of the spiral groove is not recommended.



of the extensor mechanism enablesimproved visualization of the jointsurfaces but at increased risk of post-operative extensor mechanism com-promise.

Maintaining ExtensorContinuity

Triceps-splitting or triceps-avoiding approaches have been rec-ommended for extra-articular frac-tures or simple T-type intra-articularfractures. The triceps can be splitfrom just distal to the spiral groove

to the olecranon by first palpatingand then dividing the interval be-tween the long and lateral heads.The medial head, which lies adja-cent to the humerus just distal to thespiral groove, can then be split inline with its fibers. Care must betaken when dividing the muscleproximally because the radial nervemost commonly overlies the originof the medial head for two thirds ofthe circumference of the spiralgroove.2 Another concern is partialdenervation of the lateral half of the

medial head of the triceps if its nervebranches are not preserved.

Some surgeons advocate a straightmidline split, which can be extendeddistally to reflect both the medialand lateral triceps insertions subpe-riosteally off the olecranon, provid-ing excellent intra-articular visual-ization without extensor mechanismdetachment.16-18 Others have recom-mended a 75% lateral/25% medialsplit.19 When combining a triceps-splitting approach with an olecranonosteotomy, however, the triceps split

Figure 6

The lateral triceps slide approach. Releasing the medialintermuscular septum facilitates subperiosteal mobilization ofthe medial and lateral heads of the triceps in a medialdirection. When only limited exposure is necessary, either theproximal portion of the approach (before the spiral groove)or the distal portion of the approach (distal to the spiralgroove) can be performed without the need to mobilize theradial nerve. Extended distally, an intra-articular exposuresimilar to the medial triceps slide can be achieved. (Adaptedwith permission from Gerwin M, Hotchkiss RN, Weiland AJ:Alternative operative exposures of the posterior aspect of thehumeral diaphysis: With reference to the radial nerve. J BoneJoint Surg Am 1996;78:1690-1695.)

Figure 7

The posterior triceps-splitting approach provides access tothe distal 76% of the humeral diaphysis once the radial nerveis mobilized. With this approach, the long and lateral headsof the triceps are separated, after which intramusculardivision of the medial head of the triceps is performed.Proximal extension is limited by the lateral head of the triceps.(Adapted with permission from Gerwin M, Hotchkiss RN,Weiland AJ: Alternative operative exposures of the posterioraspect of the humeral diaphysis: With reference to the radialnerve. J Bone Joint Surg Am 1996;78:1690-1695.)



should retain more of the medial-sided triceps insertion onto the ole-cranon. The osteotomized olecranoncan then be retracted medially withthe bulk of the triceps attached, andthe lateral triceps and anconeus re-flected laterally20 (Figure 8). Unlike astandard olecranon osteotomy, re-flecting the anconeus with the lat-eral triceps preserves the innervationof the anconeus, maintaining the an-coneal branch of the radial nerve asit courses along the lateral tricepsmuscle. Although small, the anco-neus assists with dynamic stabilityof the elbow and provides a vascular-

ized muscle bed for the lateral el-bow.21

Paratricipital approaches may beperformed medial to the tricepsmechanism, lateral to the triceps, orboth, with subperiosteal reflection ofthe triceps insertion in continuitywith the periosteum of the dorsal ul-na.14,21,22 The medial paratricipitalapproach with triceps reflection,combined with mobilization of theulnar nerve, provides excellent visu-alization of the entire distal humer-us and proximal ulna. This approachis best suited for elbow arthroplastyand intra-articular distal humeral

fixation of fractures with no proxi-mal extension into the humeralshaft. The lateral paratricipital ap-proach may be used for lateral col-umn intra-articular fractures, partic-ularly for the fracture extending intothe humeral shaft. For simple intra-articular or distal extra-articularfractures requiring bicolumnar fixa-tion, the medial and lateral paratri-cipital approaches may be combinedwithout reflecting the triceps off theolecranon. However, complex intra-articular fractures with proximal ex-tension beyond the distal third of thehumeral diaphysis may require me-dial and lateral paratricipital ap-proaches, with the addition of medi-al triceps reflection and ulnar nervemobilization.

Midline posterior skin incisionmay be used for any of the paratricip-ital approaches because the skinflaps can be mobilized widely to al-low access to both the medial andlateral sides. Midline skin incisionalso allows further exposure. Themedial approach requires completerelease and transposition of the ul-nar nerve to the level of the first mo-tor branch within the flexor carpi ul-naris. This approach takes advantageof the internervous plane betweenthe triceps and the brachialis mus-cles. Proximal extension of this ap-proach is blocked by the ulnar nervepiercing the intermuscular septumat the arcade of Struthers. Care mustbe taken not to injure the nerve atthis level with zealous retraction.The medial column and medial as-pect of the trochlea can be visualizedwith this approach (Figure 9, A).Distally, the dissection may be ex-tended along the dorsal ridge of theulna in the internervous plane be-tween the extensor and flexor carpiulnaris, allowing the extensor mech-anism to be subperiosteally reflectedoff the olecranon while maintainingtendofascial continuity of the exten-sor mechanism.22 In extreme flex-ion, this approach allows direct visu-alization of the joint surface nearlyequal to that of an olecranon osteot-

Figure 8

The triceps-splitting approach can be extended distally with the addition of anolecranon osteotomy. The osteotomy can be performed as illustrated, with reflectionof the olecranon medially with the medial soft-tissue attachments intact (arrow).(Adapted with permission from Ebraheim NA, Andreshak TG, Yeasting RA,Saunders RC, Jackson WT: Posterior extensile approach to the elbow joint anddistal humerus. Orthop Rev 1993;22:578-582.)



omy, with the exception of the ante-rior trochlea (Figure 10). Early activemotion can be initiated after repairof the triceps to bone using nonab-sorbable sutures. As the triceps re-mains in continuity, postoperativeweakness is minimized. In their se-ries of 49 total elbow arthroplasties,Bryan and Morrey22 reported no tri-ceps discontinuity or significantweakness.

On the lateral side, the intervalbetween the triceps and the mobilewad of three (brachioradialis, exten-sor carpi radialis longus and brevis)can be used to visualize the lateralcolumn. When visualization of theradiocapitellar joint is needed, thedissection can be extended to in-clude a Kocher approach. This main-tains the anconeus with the lateraltriceps flap, preserving both its in-nervation and blood supply.14 Theentire anconeus/triceps flap also canbe elevated subperiosteally off theposterior humerus to allow directposterior plating (Figure 9, B). Ante-rior extension of the exposure by el-

evation of the mobile wad is not rec-ommended because it places theradial nerve at risk. Moreover, anyproximal extension should identifyand preserve both the radial nerve asit pierces the intermuscular septumjust proximal to the brachioradialisorigin and the posterior antebrachi-al cutaneous nerve as it branches offthe radial nerve just distal to the spi-ral groove.13

Provided the distal extension ofany paratricipital approach has notdetached the extensor mechanismfrom the olecranon, such approach-es can be combined with olecranonosteotomy if, after inspecting thefracture site, further exposure of thejoint is deemed necessary. If the tri-ceps has already been detached, an-other option is to osteotomize andremove the proximal tip of the olec-ranon. Removing the olecranon tipprovides better intra-articular visual-ization for complex intra-articularfractures and simplifies intramedul-lary preparation of the proximal ulnafor elbow arthroplasty. In our experi-

ence, this is rarely necessary, exceptin fractures with comminution ex-tending into the anterior trochlea orfor total elbow arthroplasty.

Detaching the ExtensorMechanism

O’Driscoll21 combined a medial(triceps-reflecting) paratricipital andlateral (modified Kocher) paratricip-ital approach with distal extensionto allow the entire extensor mecha-nism to be reflected proximally. As aunit, the triceps and anconeus mus-cles are freed from their fascial at-tachments medially and laterally,maintaining only their distal attach-ment to the olecranon. Via thetriceps-reflecting anconeus pedicleapproach, the triceps and anconeusare released subperiosteally from theulna in a V-shaped tendofascial flapwith the apex distal.21 The rationalebehind this approach is to provide anexposure similar to that of an olecra-non osteotomy without the risk ofolecranon nonunion, as well as forsurgeries in which an osteotomy is

Figure 9

A, Posteromedial view of the distal humerus, right arm. Medial paratricipital approach to the distal humerus. Anteriortransposition of the ulnar nerve allows excellent visualization of the medial column. B, Posterolateral view of the distal humerus,right arm. Lateral paratricipital approach to the distal humerus. Distal extension can be achieved via the modified Kocherapproach. Proximally, mobilization of the radial nerve allows access to the entire humeral shaft up to the level of the axillary nerve.(Adapted with permission from Shildhauer TA, Nork SE, Mills WJ, Henley MB: Extensor mechanism-sparing paratricipitalposterior approach to the distal humerus. J Orthop Trauma 2003;17:374-378.)



contraindicated (eg, total elbow ar-throplasty). However, unlike an os-teotomy, which requires bone-to-bone healing, recovery of tricepsfunction requires tendon-to-bonehealing, which may represent a lim-itation of this technique. Further-more, although the joint exposureachieved with the O’Driscoll tech-nique is nearly equivalent to thatprovided by either an extended me-dial or lateral paratricipital approachalone,22 it adds the potential compli-cations of extensor detachment.

The olecranon osteotomy is themost commonly used technique forintra-articular fracture of the distalhumerus. Of the techniques de-scribed, olecranon osteotomy affordsthe best exposure of the joint surfaces.Complications include hardware mi-

gration and prominence, delayedunion, and nonunion.23 The proce-dure involves elevating the anconeusinsertion and the proximal aspect ofthe extensor and flexor carpi ulnarisorigins so as to expose the olecranonwhile maintaining the triceps attach-ment. Unless exposure of the medialcolumn is not necessary, we routinelytranspose the ulnar nerve before per-forming the osteotomy.

Ideally, an apex distal osteotomyis made at the bare spot on the troch-lear notch. Most of the osteotomycan be performed with a sagittal saw,although the articular side should bebreached with an osteotome to cre-ate an irregular joint surface for lat-er interdigitation. The olecranonwith the attached triceps is then re-flected proximally, separating the

medial triceps from the medial inter-muscular septum, and the lateral tri-ceps from the anconeus and lateralintermuscular septum. The anco-neus is denervated by this approach.When only distal exposure is re-quired, we do not attempt to identi-fy the radial nerve. However, whenthe exposure requires triceps mo-bilization >10 cm proximal to thelateral epicondyle, the radial nerveshould be identified and protected.

Repair of the osteotomy can beperformed at the close of the proce-dure with a variety of techniques, in-cluding a tension band construct withKirschner wires or an intramedullaryscrew, an intramedullary screw with-out a tension band, or plate-and-screwfixation. We prefer a tension bandtechnique with Kirschner wires andfigure-of-8 fixation.

Proximal extension can involveeither a lateral paratricipital approachwith mobilization of the entire tri-ceps muscle medially and elevationof the radial nerve24 or a triceps-splitting approach proximal to thespiral groove with paratricipital ex-tensions distal to the spiral groove.25

For isolated lateral condyle fractures,we prefer a lateral paratricipital ap-proach combined with a chevron os-teotomy, leaving all medial periostealand muscular attachments intact.The osteotomy is hinged open on thelateral side, allowing excellent visu-alization of the lateral column andarticular surface without the need toviolate the cubital tunnel or mobilizethe ulnar nerve.

Summary

Humeral exposures are limited bythe axillary nerve proximally, the ul-nar nerve medially, and the radialnerve posteriorly and laterally. Athorough understanding of the in-ternervous planes about the hu-merus is essential before undertak-ing any exposure of the humerus,particularly of the shaft. In general,nerves at risk should be identifiedand protected throughout the proce-

Figure 10

Medial triceps-reflecting approach as described by Bryan and Morrey.22 Theextensor mechanism remains in continuity with the deep fascia and periosteum ofthe proximal ulna. The ulnar nerve is transposed to gain better visualization of thedistal humerus and to protect the nerve. Excision of the olecranon tip providesexcellent intra-articular visualization. (Adapted with permission from Bryan RS,Morrey BF: Extensive posterior exposure of the elbow: A triceps-sparing approach.Clin Orthop 1982;166:189.)



dure. For the proximal humerus, thedeltoid-splitting and deltopectoralapproaches are familiar to most or-thopaedic surgeons; a healthy respectfor the potential dangers is essentialto avoid neurovascular injury. Forthe diaphysis, we prefer the lateralparatricipital approach, for both itsclean intermuscular dissection andits extensibility. Distally, for lesscomminuted fractures, we use eitheror both paratricipital approaches(with or without triceps reflection);for severely comminuted intra-articular fractures, we use an olecra-non osteotomy. Once the triceps isreflected off the olecranon, however,olecranon osteotomy no longer canbe performed.

Acknowledgment

We thank Dori Kelly, MA, Senior Ed-itor and Writer, for professionalmanuscript editing.

References

Citation numbers printed in boldtype indicate references publishedwithin the past 5 years.

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Additional Resources

CD-ROM: Selective Exposures inOrthopaedic Surgery: “CommonApproaches to the Shoulder,” byDan Guttmann, MD, and AndrewS. Rokito, MD, editors: http://www5.aaos.org/product/productpage.cfm?code=02545

Related clinical topics articlesavailable on Orthopaedic Knowl-edge Online: “Four-Part ProximalHumerus Fractures,” by JoesphZukerman, MD, Arash Araghi,MD, and Derek Plausinis, MD:http://www5.aaos.org/oko/shoulder_elbow/proximal_humeral/pathophysiology/pathophysiology.cfm

