Sling and Swathe or Coaptation Splint for Proximal Humerus Fractures
For adult proximal humerus fractures, use a sling and swathe (or simple shoulder immobilizer) for initial immobilization, as this provides adequate support while allowing patient comfort and early mobilization when appropriate.
Rationale and Clinical Approach
The available evidence does not provide specific guideline-level recommendations for splinting proximal humerus fractures in adults. The guidelines focus primarily on pediatric supracondylar fractures 1 and metastatic disease 2, neither of which directly addresses acute traumatic proximal humerus fractures in adults.
Standard Immobilization Options
For proximal humerus fractures, the following approach is recommended:
Minimally displaced or nondisplaced fractures:
- Sling and swathe (shoulder immobilizer) is the standard of care
- Provides adequate immobilization while maintaining patient comfort
- Allows for early pendulum exercises when pain permits (typically within 7-10 days)
- Duration: typically 3-4 weeks with serial radiographic follow-up
Displaced fractures requiring surgical evaluation:
- Initial immobilization with sling and swathe pending definitive treatment decision
- CT imaging should be obtained to characterize fracture pattern 3, as radiographs alone have poor inter-observer agreement for complex fractures
Key Clinical Considerations
Avoid rigid circumferential splinting for proximal humerus fractures because:
- The shoulder's anatomy and blood supply make it unsuitable for tight circumferential immobilization
- Risk of compartment syndrome in the arm if swelling occurs
- Unnecessary restriction of the elbow and hand, which should remain mobile
Monitor for complications:
- Neurovascular status, particularly axillary nerve function (deltoid sensation over lateral shoulder)
- Vascular injury if significant displacement or high-energy mechanism 3
- Loss of reduction on follow-up radiographs at 1-2 weeks
Special Populations
Pediatric proximal humerus fractures:
- For displaced epiphyseal fractures (Neer-Horwitz Type 3-4), specialized two-prong splints have shown excellent outcomes 4, 5
- These allow gradual reduction and immediate motion
- However, standard sling immobilization is also acceptable for most pediatric proximal humerus fractures
Elderly patients with complex fractures:
- Early surgical intervention (reverse total shoulder arthroplasty) may be indicated for non-reconstructable fractures 2, 6, 7
- Initial sling immobilization is still appropriate while surgical planning occurs
Common Pitfalls to Avoid
- Do not use long arm casts or rigid splints extending to the elbow—these are inappropriate for proximal humerus fractures
- Do not immobilize the elbow unless there is a concomitant elbow injury
- Do not delay imaging if fracture displacement is suspected—obtain CT for surgical planning 3
- Do not keep patients immobilized beyond 4 weeks without reassessment, as prolonged immobilization leads to stiffness
The evidence strongly supports that most proximal humerus fractures can be managed conservatively with simple sling immobilization 6, 8, with surgical intervention reserved for specific indications including fracture-dislocations, completely displaced shaft extension, or failure of conservative management in younger, active patients.