Treatment of Intraarticular Fracture Base Fifth Metacarpal
Intraarticular fractures of the base of the fifth metacarpal require surgical reduction and fixation to restore the articular surface and prevent long-term complications including pain, functional disability, and post-traumatic arthritis.
Rationale for Surgical Management
These fractures are inherently unstable and behave similarly to Bennett fractures of the thumb—inadequate reduction leads to permanent joint deformity and degenerative changes 1, 2. The evidence consistently demonstrates that:
- Cast immobilization alone cannot reliably maintain reduction of displaced intraarticular fractures at this location 2
- Inadequate repositioning results in pain, reduced grip strength, and early degenerative joint disease 3, 2
- At long-term follow-up (median 4.3 years), patients treated conservatively show high rates of intermittent pain (38%), decreased grip power (49%), and radiographic osteoarthritis (65%) 3
Surgical Technique Selection
Closed reduction with percutaneous Kirschner wire fixation under fluoroscopy is the preferred initial approach 1. The specific technique depends on fracture pattern:
- Minimally comminuted fractures: Closed reduction and percutaneous pinning using image intensification 1
- Comminuted fractures or fractures where closed restoration of the articular surface is not feasible: Open reduction with multiple Kirschner wire fixation 1, 4
- Two Kirschner wires provide adequate stability and generally produce good functional outcomes 4
Surgical Indications
Surgical fixation is indicated when 5, 6:
- Significant displacement (>3mm) is present
- Dorsal tilt >10° is observed
- Any intraarticular displacement exists in an unstable fracture pattern
Post-Operative Management
- Immobilization duration: 3-4 weeks 5, 6
- Early motion exercises: Active finger motion of uninvolved fingers should begin immediately to prevent stiffness 5, 6
- Radiographic follow-up: Obtain imaging at approximately 3 weeks post-immobilization to assess healing and at the time of immobilization removal to confirm adequate healing 5, 6
Critical Pitfalls to Avoid
- Attempting conservative management for displaced intraarticular fractures: This consistently leads to poor outcomes with pain, weakness, and arthritis 3, 2
- Prolonged immobilization: Excessive immobilization causes stiffness that may require multiple therapy visits or additional surgical intervention 6
- Inadequate follow-up imaging: May miss delayed displacement requiring intervention 5
- Failure to restore the articular surface: Even minor articular incongruity leads to post-traumatic arthritis 1, 3
Expected Outcomes
When treated with appropriate surgical reduction and fixation, patients achieve good functional outcomes with no arthritic changes at follow-up 1. Immobilization-related adverse events (skin irritation, muscle atrophy) occur in approximately 14.7% of cases but are generally minor 5, 6.