Treatment of Distal 5th Metacarpal Fractures
For nondisplaced or minimally displaced fractures (<30° angulation, no malrotation, <5mm shortening), functional taping or removable splinting with early mobilization is the preferred treatment, providing faster functional recovery than cast immobilization.
Initial Assessment
Evaluate the following key parameters to determine treatment approach:
- Angulation: Measure the degree of apex dorsal angulation (displacement of the metacarpal head in flexion) 1, 2
- Rotation: Assess for any rotational deformity by examining finger cascade and nail plate alignment 3, 1
- Shortening: Measure axial shortening (significant if >5mm) 1
- Joint involvement: Determine if the fracture extends into the metacarpophalangeal joint 3
- Fracture stability: Assess whether the fracture pattern is stable or inherently unstable 3
Conservative Management (Preferred for Stable Fractures)
Functional taping is superior to cast immobilization for stable fractures, providing significantly earlier functional recovery with equivalent long-term outcomes 4.
Indications for Conservative Treatment:
Treatment Protocol:
- Functional taping (buddy taping) is the first-line conservative approach, allowing earlier return of mobility, power-grip, and strength compared to plaster immobilization 4
- If immobilization is used, position the metacarpophalangeal joint in 60-90° flexion with fingers in full extension for a short period only 1
- Initiate active finger motion exercises immediately to prevent stiffness, which does not adversely affect adequately stabilized fractures 5
- Obtain radiographic follow-up at approximately 3 weeks to confirm adequate healing 5
Important Caveat:
- Closed reduction of displaced 5th metacarpal neck fractures (boxer's fractures) is often unsuccessful and does not maintain reduction 1
- Changes in fracture angulation occur only in fractures that have been reduced, not in those treated in their initial position 4
Surgical Management
Surgery is indicated when angulation exceeds 30-45°, malrotation is present, or there is intra-articular involvement with displacement 3, 1, 2.
Surgical Indications:
- Displacement >30-45° 1, 2
- Malrotation 1, 2
- Intra-articular fractures with displacement 3
- Open fractures 1
- Multiple metacarpal fractures 1
Surgical Technique Selection:
Intramedullary K-wire fixation is the reference technique, providing superior mobility outcomes compared to locking plates 2.
- For simple shaft or spiral fractures: Intramedullary K-wire or intramedullary compression screws are both effective options, with screws showing a tendency toward earlier return to work 6
- For base fractures: Closed reduction with percutaneous pinning under fluoroscopy is preferred 3
- For comminuted base fractures: Open reduction with multiple K-wire pinning when closed restoration of the articular surface is not feasible 3
- Avoid locking plates: Despite allowing immediate mobilization, locking plates paradoxically result in significantly worse metacarpophalangeal joint mobility (59% vs 98% flexion compared to healthy side) and higher complication rates without justifying the extra cost 2
Postoperative Management:
- K-wire fixation requires approximately 6 weeks of immobilization 2
- Active finger motion exercises should be performed following surgery to prevent stiffness 7
- Monitor for complications including wire migration (common with K-wires), neurologic lesions, and stiffness 2
Key Clinical Pitfalls
- Do not attempt closed reduction of significantly displaced 5th metacarpal neck fractures - it is typically unsuccessful 1
- Avoid prolonged immobilization - functional taping provides faster recovery than casting 4
- Do not use locking plates routinely - they provide inferior mobility outcomes compared to K-wires despite higher cost 2
- Inadequate reduction of base fractures can result in pain, functional disability, and osteoarthritic changes due to their inherent instability 3