Surgical Recommendations for Base of Fifth Metacarpal Fractures
For base of fifth metacarpal fractures, surgical intervention with closed or open reduction and percutaneous pinning is recommended due to inherent instability of these fractures, which can lead to pain, functional disability, and post-traumatic arthritis if inadequately reduced. 1
Key Distinction: Base vs. Neck Fractures
Base of fifth metacarpal fractures are fundamentally different from the more common neck fractures (boxer's fractures) and require more aggressive treatment. Base fractures are inherently unstable and involve the carpometacarpal joint, making them prone to displacement and arthritic changes. 1
Surgical Indications
Proceed with surgical fixation when:
- Intra-articular involvement is present - Any articular surface disruption requires anatomic restoration to prevent post-traumatic arthritis 1
- Extra-articular fractures with displacement - Even extra-articular base fractures demonstrate instability requiring fixation 1
- Inability to achieve or maintain closed reduction - The inherent instability of these fractures makes conservative treatment unreliable 1
Surgical Technique Algorithm
Step 1: Attempt Closed Reduction with Percutaneous Pinning
- Use image intensifier guidance for fracture reduction 1
- Insert Kirschner wires percutaneously to maintain reduction 1
- This approach is preferred for simple fracture patterns with achievable closed reduction 1
Step 2: Open Reduction for Complex Patterns
- Perform open reduction when closed restoration of articular surface is unfeasible 1
- Use multiple Kirschner wire fixation for comminuted fractures 1
- Direct visualization ensures anatomic restoration of joint surface 1
Evidence Quality and Outcomes
The recommendation for surgical treatment of base fractures comes from retrospective case series showing uniformly good functional outcomes with no arthritic changes when anatomic reduction and pinning are achieved. 1 This contrasts sharply with fifth metacarpal neck fractures, where conservative treatment shows superior outcomes with lowest complication rates. 2
Critical Pitfalls to Avoid
Do not treat base fractures like neck fractures. While fifth metacarpal neck fractures tolerate significant angulation (up to 30 degrees) and respond well to conservative management 3, 4, 2, base fractures require anatomic reduction regardless of displacement degree. 1
Do not rely on cast immobilization alone. Unlike neck fractures where functional treatment or brief immobilization suffices 4, 5, base fractures demonstrate inherent instability that leads to loss of reduction with casting alone. 1
Do not accept articular incongruity. Any step-off or gap in the joint surface mandates surgical intervention, as inadequate reduction results in pain, functional disability, and osteoarthritic changes. 1
Postoperative Management
Following surgical fixation, early mobilization should begin once soft tissue swelling resolves, though the specific timing depends on fracture stability and fixation strength. 3 Immobilization beyond 3-4 weeks is unnecessary and potentially harmful. 4
Strength of Evidence Caveat
The evidence for base fractures specifically is limited to retrospective case series 1, as most metacarpal fracture studies focus on neck fractures. 5, 2 However, the consistent finding of instability and poor outcomes with conservative management in base fractures, combined with uniformly good surgical outcomes, supports the recommendation for operative intervention. 1