Overview
Proximal humerus fractures are common injuries involving the upper end of the humerus near the shoulder joint. They account for approximately 5–6% of all fractures and represent the third most common fracture in the elderly after hip and distal radius fractures. These injuries typically occur following low-energy falls in osteoporotic individuals, but can also result from high-energy trauma such as road traffic accidents or sports injuries in younger patients.
The management of proximal humerus fractures depends on fracture pattern, displacement, bone quality, patient age, and functional demands. While many fractures can be treated conservatively, complex displaced fractures may require surgical fixation or arthroplasty.
Anatomy
The proximal humerus forms the shoulder joint by articulating with the glenoid cavity of the scapula. Important anatomical structures include:
- Humeral head
- Greater tuberosity
- Lesser tuberosity
- Surgical neck
The rotator cuff muscles attach to the tuberosities and play a major role in fracture displacement. The blood supply of the humeral head is mainly from the anterior and posterior circumflex humeral arteries, particularly the arcuate artery.
Epidemiology
- Accounts for 5–6% of all fractures
- Common in elderly osteoporotic women
- Third most common fracture in elderly population
- Increasing incidence with aging population
| Age Group | Mechanism |
|---|---|
| Elderly | Low energy fall on outstretched hand |
| Young adults | High energy trauma or sports injury |
Mechanism of Injury
- Fall on outstretched hand
- Direct blow to shoulder
- High-energy trauma
- Seizure or electric shock (rare)
Classification
The most commonly used classification system for proximal humerus fractures is the Neer classification. It is based on the number of displaced fracture segments.
| Type | Description |
|---|---|
| One-part | No segment displaced |
| Two-part | One segment displaced |
| Three-part | Two segments displaced |
| Four-part | All segments displaced |
A fracture segment is considered displaced if it is separated by more than 1 cm or angulated by more than 45 degrees.
Clinical Features
- Severe shoulder pain
- Swelling and bruising around shoulder
- Restricted shoulder movement
- Deformity in severe displacement
- Ecchymosis extending to chest wall
Neurovascular examination is essential because the axillary nerve may be injured in proximal humerus fractures.
Investigations
- AP shoulder radiograph
- Scapular Y view
- Axillary view
- CT scan for complex fractures
CT scans are particularly helpful in evaluating fracture comminution and planning surgical treatment.
Nonoperative Management
Approximately 80% of proximal humerus fractures are minimally displaced and can be managed conservatively.
- Sling immobilization
- Analgesics
- Early pendulum exercises
- Gradual physiotherapy
Operative Management
| Procedure | Indications |
|---|---|
| ORIF with locking plate | Displaced fractures |
| Intramedullary nail | Selected surgical neck fractures |
| Hemiarthroplasty | Complex fractures in elderly |
| Reverse shoulder arthroplasty | Severely comminuted fractures |
Complications
- Avascular necrosis of humeral head
- Malunion
- Nonunion
- Shoulder stiffness
- Axillary nerve injury
Exam Pearls
- Most fractures treated conservatively
- Neer classification commonly used
- Axillary nerve injury should be assessed
- Four-part fractures have high AVN risk