FRACTURES OF THE PROXIMAL HUMERUS

Presented by Mahsa Mehdizade

Dr. MardaniPorsina Hospital

Spring 1392

IncidenceProximal humerus fxs comprise 4-5% of all fxs.

Minimal displacement 80%Two-part fxs 10%Three-part fxs 3%Four-part fxs 4%Articular surface fxs 3%

AnatomyComprised of four segments:

Humeral headGreater tuberosityLesser tuberosityHumeral shaft

Neurovascular SupplyAnterior and posterior humeral circumflex arteriesArcuate artery-continuation of the ant humeral circumflex and supplies most of the humeral head.Axillary nerve-most commonly injured

Forces on SegmentsGreater tuberosity is displaced superiorly and posteriorly by the supraspinatus and external rotators.Lesser tuberosity is displaced medially by the subscapularis.The shaft is displaced medially by the pectoralis major.

Mechanism of InjuryElderly, osteoporotic, usually female: fall on outstretched arm.Young adults: high-energy trauma; usually more severe fxs and dislocations

Radiographic EvaluationA/P viewScapular Y viewAxillary view

Best view for glenoid articular fxs and dislocations

CT scan: helpful in evaluating articular involvement and degree of displacement

ClassificationsNeer-four parts: greater and lesser tuberosities; shaft; humeral head.

A part is displaced only if >1cm of displacement or 45 degrees of angulation is present.At least 2 views must be obtained

AO-emphasizes the vascular supply to the articular segment

Three types:• Type A: Extraarticular unifocal fxs• Type B: Extraarticular bifocal fxs• Type C: Articular fxs

Not commonly used

Neer Classification

Treatment OptionsClosed reduction

ImmobilizationEarly ROM if stable

External stabilizationPercutaneous pinsExternal fixatorIlizarov frame

Open reduction and internal fixation

Screw fixationTension bandingButtress platingFix-Clip system

Intramedullary fixation

Rush rodsEnder’s nailsNails with interlocking screws

Excisional arthroplastyHemiarthroplasty

Fractures to Consider for Closed Treatment

Minimally displaced 2 part fx’s (or positional reduction of significant displacement)GT fractures should be <5mm). Minimally displaced 3- and 4-part fractures

Fractures to Consider for ORIFDisplaced GT fx (> 5 mm)LT fx with involvement of articular surfaceDisplaced or unstable surgical neck fxDisplaced anatomic neck fx in young pt.Displaced, reconstructible 3- and 4-part fractures

Fractures to Consider Hemiarthroplasty

Young/Middle agenonreconstructable articular surface (severe head split) or extruded anatomic neck

Elderlymany 4 partssome severe 3 partsmost 3,4 part fracture dislocationsmost head splits

Potential ComplicationsNeurologic injury

Brachial plexus-Stableforth reported an incidence of 6.1%Axillary-common

Vascular injuryStableforth also reported a 4.9% incidence of arterial injury with displaced fxs; most commonly the axillary arteryAn intact radial pulse doe not exclude an arterial injury so keep it in mind.

Complications cont.Avascular necrosis

Hagg and Lungberg reported an incidence of 3 – 14% with 3- part fxs and 13 – 34% with 4-part fxs, using closed reduction.

Nonunion (uncommon)Malunion – often associated with AVNAdhesive capsulitisMyositis ossificansInfection