Proximal Humerus Fracture

Proximal Humerus Fracture

The most common fracture pattern of the proximal humerus is a transverse fracture. Most fractures are non-displaced and are treated non-operatively.

It has a bimodal distribution. 70% of cases occur in women. It is the 3rd most common fracture in the elderly, typically occurring after a fall.

Neer classification of proximal humerus fracture

The proximal humerus is divided into 4 fragments:

1. Head/articular surface
2. Greater tuberosity
3. Lesser tuberosity
4. Humeral shaft

Fragments are considered separate parts if they are displaced > 1 cm (10 mm) or > 45 degrees of angulation. Some use 0.5 cm (5mm) as a measure of displacement.

2-part fractures

Fracture	Description	Treatment
Surgical neck fracture	Most common pattern. The shaft is pulled anteriorly and medially by the pectoralis major	Closed reduction and sling. Operative treatment iwth CRPP, ORIF and IM nail
Greater tuberosity	The greater trochanter is pulled superiorly and posteriorly by the rotator cuff	Non-operative treatment if displaced < 5mm. Operative treatment if displaced > 5mm
Lesser tuberosity	Associated with forceful impaction of the humral head against the glenoid cavity during posterior dislocation.	Non-operative treatment
Anatomical neck	Rare	Non-operative treatment in minimally displaced. ORIF in young patients. ORIF, hemiarthroplasty or reverse total shoulder arthroplasty in the elderly

3-part fracture

Fracture	Description	Treatment
Surgical neck and greater trochanter	The articular fragment is internally rotated	Non-operative treatment for minimally displaced fractures. Operative treatment in young patients. Arthroplasty in elderly patients.
Surgical neck and lesser trochanter	The articular surface is pulled anteriorly by the tortator cuff	Non-operative treatment. Operative treatment in young patients. Arthroplasty in elderly patients.

4-Part fracture

Fracture	Description	Treatment
Valgus impacted	There is alignement between the medial shaft and head segment on X-ray	Operative treatment
4-part with head splittting fracture	Has a high risk of avascular necrosis. The shaft is pulled medially by the pectoralis major	Operative treatment

• Risk factors
  • Osteoporosis
  • Diabetes
  • Epilepsy
  • Female gender
• Mechanism of injury
  • Fall onto outstretched hand (FOOSH) from a standing height in older osteoporotic patients
  • High-energy trauma e.g. MVA in young patients
  • Excessive shoulder abduction in individuals with osteoporosis
  • Direct trauma
  • Electric shock or seizure
  • Pathologic fracture (malignant or benign process)
• Associated injuries
  • Axillary nerve injury
  • Arterial injury
• Signs and symptoms
  • Shoulder pain
  • Swelling
  • Tenderness
  • Painful active/passive and decreased range of motion
  • Signs of brachial plexus and axillary nerve injury
  • Ecchymoses over the upper arm and chest
• Physical examination
  • Axillary nerve damage
    • Check for arm abduction and palpate radial nerve
    • Check for numbness over the regimental patch
• Investigation
  • XR affected shoulder (AP, Scapular Y-view, and axillary view)
    • Pseudosubluxatoin due to muscle atony and blood in the capsule
  • CT scan: for pre-operative planning, intra-articular comminuted fractures or concern for head-split fracture
  • MRI: for associated rotator cuff injury
• Indications for non-operative treatment
  • Minimally displaced surgical and anatomic neck fractures
  • Greater tuberosity fracture < 5mm displaced
• Indications for operative treatment
  • 2-part surgical neck fracture
  • Greater tuberosity fracture > 5mm displaced (will lead to impingement and loss of abduction)
  • 3-part and 4-part fracture in young patients
  • Head-split fracture in young patients
• Non-operative treatment
  • Sling immobilization for 2 – 3 weeks
  • Immediate physiotherapy for early range of motion
• Operative treatment
  • Closed reduction percutaneous pinning (CRPP)
  • Open reduction internal fixation (ORIF)
  • Intramedullary nailing
  • Hemiarthroplasty
  • Reverse shoulder arthroplasty
• Complications
  • Avascular necrosis: less frequent than in lower extremity fractures
  • Neurologic injury: invovles the axillary nerve, subscapular nevre or musculocutaneous nerve
  • Malunion: commonly varus apex-anterior or malunion of the greater trochanter
  • Non-union: commonly affects 2-part surgical neck fracture
  • Rotator cuff injury
  • Injury to long head of biceps tendon
  • Missed posterior dislocation (should be considered in patients with lesser tuberosity fracture)
  • Adhesive capsulitis
  • Post-traumatic arthritis
  • Infection

Proximal Humerus Fracture Malunion

Defined as malposition of humeral tuberosities: rotation, angulation and/or off set of the head-shaft junction, or articular incongruities

• 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 steroid use
• Signs and symptoms
  • Pain and weakness
  • Limited range of motion
• Physical examination
  • Muscle atrophy
  • Diffuse tenderness
  • Blocks in range of motion or crepitus in both active and passive movement
  • Weakness in abduction and external rotation (greater tuberosity malunion)
  • Weakness in internal rotation (lesser tuberosity malunion)
  • Instability (positive apprehension test in humeral head malunion)
• Investigations
  • X-ray (AP, scapular Y and axillary view)
    • Neck shaft angle- in varus or valgus (<120 or >150)
    • Greater tuberosity superiorly and posteriorly displaced, externally rotated (>1cm from native anatomical position)
    • Lesser tuberosity medially displaced (>1cm from native anatomical position)
• Non-operative treatment
  • NSAIDs
  • Physical therapy
  • Occasional corticosteroid therapy
• Operative treatment
  • Humeral head preservation techniques
  • Hemiarthroplasty
  • Total shoulder arthroplasty
  • Reverse total shoulder arthroplasty