What type of splint is recommended for a fourth metacarpal (4th MC) neck fracture?

Splinting for Fourth Metacarpal Neck Fracture

For a fourth metacarpal neck fracture, a hand-based functional splint that immobilizes the fracture while allowing motion of the metacarpophalangeal, interphalangeal, and radiocarpal joints is recommended. 1

Rationale for Hand-Based Functional Splinting

Hand-based functional splinting offers several advantages for fourth metacarpal neck fractures:

• Maintains fracture reduction while allowing functional motion throughout treatment 1
• Enables early or immediate return to pre-injury activities 1
• Results in low patient morbidity 1
• Prevents post-treatment stiffness, which is a significant concern with metacarpal fractures 1

Splinting Approach

1. Type of splint: Hand-based functional splint that:

   • Immobilizes the fracture site
   • Allows metacarpophalangeal joint motion
   • Allows interphalangeal joint motion
   • Permits radiocarpal joint motion 1

2. Duration of splinting:

   • Average duration: approximately 24 days 1
   • Clinical and radiographic reassessment should be performed at 2-3 weeks to evaluate fracture healing progression 2

3. Position of splinting:

   • Splint the injured extremity in the position found unless straightening is necessary for safe transport 3
   • Avoid excessive angulation that could compromise function

Indications for Surgical Management

While splinting is appropriate for most fourth metacarpal neck fractures, consider surgical options when:

• Angulation exceeds 45° 4
• Rotational deformity is present 4
• Shortening exceeds 5 mm 5

Surgical options include:

• K-wire fixation (provides better mobility outcomes than plating) 4
• Percutaneous intermetacarpal and external fixation for unstable fractures 5

Post-Splinting Rehabilitation

1. Early phase (during splinting):

   • Active motion exercises for non-immobilized joints to prevent stiffness 2

2. After splint removal:

   • Progressive range of motion exercises 2
   • Directed home exercise program 2
   • Strengthening exercises for intrinsic hand muscles 2

3. Long-term rehabilitation (6-8 weeks and beyond):

   • Balance training and fall prevention to minimize risk of further injury 2
   • Full recovery typically expected within 6-8 weeks 2

Monitoring and Follow-up

• Regular radiographic assessment to ensure proper alignment is maintained 1
• Monitor for signs of complications such as malunion or stiffness
• In a study of 33 patients with metacarpal fractures treated with hand-based functional splinting, 27 of 30 patients showed no change in alignment from start to end of splinting 1

Caution

• Ensure the splint does not compromise circulation by overtightening 3
• If the fractured extremity appears blue, purple, or pale, seek immediate medical attention 3
• For open fractures, cover with a clean dressing to reduce risk of contamination and infection 3

The evidence strongly supports that a hand-based functional splint provides excellent maintenance of fracture reduction while allowing functional motion throughout treatment, making it the preferred option for fourth metacarpal neck fractures.