Surgical Exposures of the Humerus - Exposures of the Humerus The neurovascular and muscular anatomy about the humerus ... humerus, humeral shaft, and distal humerus. There are indications,

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  • 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 patients 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.LukesRoosevelt 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. LukesRoosevelt 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. LukesRoosevelt 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


    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, thethree 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.

    Surgical Exposures of the Humerus

    756 Journal of the American Academy of Orthopaedic Surgeons