What is the best splint for a radial head or capitellum fracture with a small fragment and uncertain origin?

Initial Immobilization for Radial Head/Capitellum Fracture with Small Fragment

For a radial head or capitellum fracture with a small indeterminate fragment, use a posterior long-arm splint with the elbow at 90 degrees for 48 hours, followed by immediate removal and active range of motion exercises.

Rationale for Splinting Approach

The optimal management depends on whether the fracture is displaced or nondisplaced:

For Nondisplaced or Minimally Displaced Fractures (<3mm displacement)

• Brief immobilization (48 hours maximum) followed by early mobilization produces superior outcomes compared to prolonged immobilization 1
• A simple posterior long-arm splint or sling for 2 days, then active mobilization, results in better range of motion, strength, and functional outcomes compared to 7 days of casting 1
• Immediate mobilization without any immobilization causes worse pain in the first 3 days without additional benefit 1

Critical Decision Point: Assess Fragment Size and Displacement

• If the fragment shows >3mm displacement, >10° angulation, or >4mm displacement with >30° angulation, surgical management is indicated rather than conservative splinting 2, 1
• Small fragments that cannot be adequately fixed should be excised rather than left in place, as incomplete removal of intraarticular fragments leads to poor outcomes 3

Specific Splinting Technique

• Apply a posterior long-arm splint with the elbow flexed at 90 degrees and the forearm in neutral rotation 4
• Duration: 48 hours only 1
• After 48 hours, remove the splint and begin active range of motion exercises 1

Essential Post-Immobilization Protocol

• Active finger motion exercises must begin immediately after diagnosis to prevent stiffness, which is the most functionally disabling complication 2, 5
• Finger motion does not adversely affect adequately stabilized fractures 2
• Avoid over-immobilization beyond 48 hours, as excessive immobilization causes stiffness that is difficult to treat and may require additional surgical intervention 5

Follow-Up Imaging Schedule

• Obtain radiographic follow-up at approximately 3 weeks to confirm adequate healing 2
• Repeat imaging at the time of full mobilization 2

Common Pitfalls to Avoid

• Do not immobilize for 7 days or longer—this significantly worsens functional outcomes 1
• Do not leave small intraarticular fragments untreated if they are causing mechanical symptoms, as incomplete fragment removal leads to poor results 3
• Be vigilant for associated medial collateral ligament injuries, which are often overlooked and contribute to treatment failure 6, 3
• Small capitellum fragments can impale the radial head and may not be visible on plain radiographs—maintain high suspicion if the fracture fails to respond as expected 6

When Surgery Is Required Instead

• Displacement >4mm with angulation >30° 1
• Fragment size adequate for fixation with the larger fragment amenable to open reduction and internal fixation 3
• Best surgical approach: ORIF of the larger, more suitable fracture combined with excision of smaller fragments 3
• For very small fragments from either the radial head or capitellum that cannot be fixed, excision works well if other elbow structures are competent 4