Summary Proximal Humerus Fracture Nonunion and Malunion are common complications associated with proximal humerus fractures which can lead to persistent shoulder pain, instability, and restricted motion. Diagnosis is made radiographically with shoulder radiographs demonstrating malposition of the humeral tuberosities, varus/vaglus head-shaft angulation, articular incongruities, or absence of bony union. Treatment ranges from nonoperative to revision ORIF to shoulder arthroplasty depending on severity of malunion, available bone stock, patient age and activity demands. Epidemiology Incidence common proximal humerus fractures account for 4% to 5% of all fractures Risk factors for nonunion fracture characteristics 2-part (surgical neck) fracture patterns humeral head split displaced tuberosity fractures patient factors osteoporosis chronic renal disease chronic alcohol or steriod use smoking Etiology Pathophysiology origin of malunion initial fracture displacement secondary displacement after loss of reduction failure of internal fixation humeral head malunion varus/valgus impacted (>1cm displacement) articular surface incongruity (e.g. head split) greater tuberosity malunion usually displaced posterior, superior and externally rotated lesser tuberosity malunion usually displaced medial Associated conditions rotator cuff tearing osteonecrosis of humeral head glenohumeral joint issues stiffness post-traumatic arthritis subluxation or dislocation subacromial impingement Anatomy Humeral head shape spheroidal in 90% of individuals size average diameter is 43 mm orientation retroverted 30° from transepicondylar axis of the distal humerus neck-shaft angle usually 130° to 140° Greater tuberosity position important for rotator cuff muscle fuction horizontal position medial edge of tuberosity is 10mm lateral to humeral canal axis vertical position superior edge of tuberosity is 6mm inferior to upper edge of humeral head Classification Beredjiklian Classification Type I Malposition of the greater or lesser tuberosity( e.g. >1 cm from native anatomical position) Type II Articular incongruity (e.g.intra-articular fracture extension, osteoarthritis) Type III Articular surface malalignment ( e.g. >45°of deformity with respect to the humeral shaft in the coronal, sagittal, or axial planes Boileau Classification Type I Humeral head necrosis or impaction Type II Chronic dislocations or fracture-dislocations Type III Nonunion of the surgical neck Type IV Severe malunion of the tuberosity Presentation History initial evaluation date and mechanism of injury current and prior function handedness treatment to date specific goals of treatment Symptoms pain and weakness limitations Physical exam inspection features of systemic disease muscle atrophy diffuse tenderness motion active and passive shoulder range-of-motion blocks or crepitus should be noted rotator cuff greater tuberosity malunion = weakness with abduction, external rotation lesser tuberosity malunion = weakness with internal rotation instability humeral head malunion = apprehension test neurovascular check axillary nerve function Imaging Radiographs recommended views true AP, scapular Y, axillary optional views apical oblique Velpeau West Point axillary findings neck-shaft angle = varus or valgus greater tuberosity = superiorly and posteriorly displaced, externally rotated lesser tuberosity = medialized measurements humeral head > 45° of deformity in any plane symptomatic articular incongruity neck-shaft angle <120° or >150° greater or lesser tuberosity >1 cm from native anatomical position CT scan indications preoperative planning assess bone stock, orientation and articular surface findings humeral head and greater tuberosity displacement glenoid version and glenoid bone stock articular injury MRI indications preoperative planning soft-tissue structures findings rotator cuff or labral injury deltoid atrophy secondary to axillary nerve injury long-head biceps injury osteonecrosis Studies Labs CBC, ESR, CRP, blood cultures to rule out infection Electrodiagnositcs concern for nerve dysfunction Treatment Nonoperative NSAIDS, physical therapy, occasional corticosteroid injection indications low-demand patient painless shoulder limitations unable to comply with the rehabilitation protocol modalities physical therapy maximize ROM and strengthening program outcomes impacted varus and valgus fractures show good-to-excellent results return to 90% of normal function Operative ORIF +/- osteotomy, subacromial decompression, and soft tissue technique indications symptomatic malunion following nonoperative treatment failed internal fixation anatomical requirements adequate bone stock for fixation preserved articular surface intact blood supply to humeral head outcomes complication rates associated with surgical management of malunions are higher than those associated with acute fractures shoulder arthroplasty indications symptomatic malunion following nonoperative treatment failed internal fixation anatomical requirements inadequate bone stock for fixation techniques articular incongruity, destruction or collapse (e.g. osteonecrosis or head-split) compromised blood supply chronic dislocation techniques hemiarthroplasty total shoulder arthroplasty reverse total shoulder arthroplasty greater improvement in functional outcome scores than hemiarthroplasty lower complication rates than hemiarthroplasty techniques ORIF +/- osteotomy, subacromial decompression, and soft tissue technique technique humeral head deformities minor deformity techniques open/arthroscopic tuberoplasty +/- acromioplasty +/- capsular release +/- bursectomy severe deformity techniques varus/valgus osteotomy +/- rotational osteotomy and lateral plate fixation treated with corrective osteotomy/fixation if patient is young or active may be augmented with strut allograft for poor bone stock greater tuberosity deformities <1.5 cm displacement arthroscopic subacromial decompression +/- rotator cuff repair >1.5 cm displacement open/arthroscopic tuberosity osteotomy +/- subacromial decompression Shoulder arthroplasty technique hemiarthroplasty anatomic total shoulder arthroplasty reverse total shoulder arthroplasty Complications Persistent pain and weakness Stiffness Loss of fixation Infection Bleeding