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 login to view 1 more bullet vertical position login to view 1 more bullet 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 login to view 1 more bullet rotator cuff login to view 2 more bullets instability login to view 1 more bullet 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 login to view 3 more bullets greater or lesser tuberosity login to view 1 more bullet 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 login to view 3 more bullets modalities login to view 2 more bullets outcomes login to view 2 more bullets Operative ORIF +/- osteotomy, subacromial decompression, and soft tissue technique indications login to view 7 more bullets outcomes login to view 1 more bullet shoulder arthroplasty indications login to view 8 more bullets techniques login to view 5 more bullets techniques ORIF +/- osteotomy, subacromial decompression, and soft tissue technique technique humeral head deformities login to view 10 more bullets greater tuberosity deformities login to view 4 more bullets Shoulder arthroplasty technique hemiarthroplasty anatomic total shoulder arthroplasty reverse total shoulder arthroplasty Complications Persistent pain and weakness Stiffness Loss of fixation Infection Bleeding