Is a below-elbow (BE) slab sufficient for a nondisplaced ulna fracture near the elbow?

Below-Elbow Slab for Nondisplaced Ulna Fracture Near the Elbow

A below-elbow slab is sufficient for a nondisplaced ulna fracture near the elbow, as multiple studies demonstrate that below-elbow immobilization achieves equivalent healing outcomes to above-elbow casting with shorter immobilization periods and better functional recovery. 1, 2

Evidence Supporting Below-Elbow Immobilization

Primary Treatment Approach

• Below-elbow casting is the recommended treatment for isolated nondisplaced ulnar shaft fractures, with no advantage demonstrated for above-elbow immobilization 2
• A prospective randomized study of 31 patients found no significant difference in time to union between long arm and short arm plaster immobilization 2
• Short arm casting for 8 weeks is specifically recommended based on randomized controlled trial evidence 2

Superior Outcomes with Below-Elbow Treatment

• In a prospective series of 102 isolated ulnar shaft fractures treated with below-elbow casts, there was no further displacement, no malunion, and no nonunion 1
• Average immobilization period was only 24 days in the below-elbow cast group 1
• Patients treated with short arm casts avoided the significant motion loss seen in 2 patients from both long arm cast groups 2

Specific Considerations for Fractures Near the Elbow

• For nondisplaced epicondylar fractures specifically, posterior splinting provides adequate stabilization while allowing appropriate healing 3
• The American Academy of Orthopaedic Surgeons recommends posterior splinting for nondisplaced epicondylar fractures based on moderate quality evidence 3
• Posterior splints provide superior pain relief within the first 2 weeks compared to other immobilization techniques 3

Critical Management Points

Initial Immobilization Protocol

• Apply a below-elbow posterior splint with the elbow at 90° flexion for initial immobilization 4
• Average immobilization duration should be approximately 3-4 weeks, though some protocols extend to 8 weeks 1, 2

Mandatory Follow-Up Schedule

• Obtain serial radiographs at 1 week, 3 weeks, and 6 weeks to monitor for late displacement and assess healing 3, 4
• Regular radiographic follow-up is essential to detect any delayed displacement that could require intervention 3

Common Pitfalls to Avoid

Overtreatment Risk

• Avoid above-elbow immobilization unless there is documented instability, as it provides no healing advantage and increases risk of elbow stiffness 2
• Two patients in long arm cast groups lost significant motion at final follow-up, while short arm casting avoided this complication 2

Inadequate Immobilization

• Do not use Ace wrap alone—70% of patients treated with Ace wrap failed treatment due to pain and required conversion to plaster immobilization 2
• Ace wrap patients demonstrated significantly greater angulation than those in long arm casts 2

Monitoring for Displacement

• Failure to obtain adequate follow-up radiographs can miss late displacement requiring surgical intervention 3
• Age, sex, fracture pattern, and initial displacement do not significantly influence time to union, so treatment protocols can be standardized 2

When Below-Elbow Treatment Is Insufficient

• If the fracture involves the olecranon process with displacement, open reduction and internal fixation becomes necessary 5
• Combined radius and ulna fractures generally require surgical correction rather than immobilization alone 6
• Persistent instability with >10° joint widening on stress fluoroscopy after reduction warrants surgical intervention 4