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Proximal Humerus Fracture Malunion

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Topic updated on 12/01/15 5:31pm
Introduction
  • Malposition of the humeral tuberosities; rotation, angulation, and/or offset of the head-shaft junction; or articular incongruities
  • Epidemiology
    • incidence
      • proximal humerus fractures account for 4% to 5% of all fractures 
    • risk factors
      • fracture characteristics
        • 3 or 4 part fracture patterns
        • humeral head split
        • displaced tuberosity fractures  
      • patient factors
        • osteoporosis
        • chronic renal disease
        • chronic alcohol or steriod use
  • Pathophysiology
    • origin of malunion
      • inital 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 agle usually 13 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 et al. 
 Beredjiklian
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 et al.
 Boileau
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
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 corticosteriod injection
      • indications
        • low-demand patient
        • painless shoulder limitations
        • unable to comply with 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 fuction
  • Operative
    • humeral head preserving techniques
      • 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
      • techniques
        • 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 
            • augmentation 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
      • outcomes
        • complication rates associated with surgical management of malunions are higher than those associated with acute fractures
    • humeral head replacing techniques
      • 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 
Complications
  • Persistent pain and weakness
  • Stiffness
  • Loss of fixation
  • Infection
  • Bleeding

 

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(OBQ06.206) A 24-year-old female sustains a surgical neck proximal humerus fracture in a motor-vehicle collision. She undergoes open reduction and internal fixation but heals in 45 degrees of varus and has significant limitation of shoulder range of motion despite 9 months of conservative treatments. What is the most appropriate treatment at this time? Topic Review Topic

1. Manipulation under anesthesia
2. Humeral head resurfacing
3. Shoulder hemiarthroplasty
4. Revision open reduction internal fixation with osteotomy
5. Reverse total shoulder arthroplasty

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HPI - Operated 4 months ago of proximal humerus fracture.
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11/19/2015
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