Treatment of MCP Finger Avulsion Fractures
For MCP finger avulsion fractures, treatment depends on fragment shape and size: triangular or rectangular fragments involving the articular surface require surgical fixation with lag screw through a dorsal approach, while round fragments without articular involvement can be treated conservatively with buddy taping and early active mobilization. 1
Initial Assessment and Imaging
- Obtain standard 3-view radiographs (PA, lateral, and oblique) to assess the fracture pattern and fragment characteristics 2
- Evaluate for obvious deformity, swelling, bruising, severe pain with movement, or inability to move the digit 2, 3
- If the extremity appears blue, purple, or pale, activate emergency services immediately as this indicates vascular compromise 2
- Cover any open wounds with a clean dressing before splinting to prevent infection 2, 3
Treatment Algorithm Based on Fragment Characteristics
Surgical Indications (Triangular or Rectangular Fragments)
Operate when the fragment is triangular or rectangular in shape because these fractures involve the articular surface 1:
- Displaced fractures should undergo primary internal fixation using a single lag screw through a dorsal approach 4
- This approach allows gentle mobilization and facilitates union 4
- Seven of eleven patients treated with primary fixation achieved full range of motion by 3 months 4
Even undisplaced fractures with articular involvement are prone to nonunion when treated conservatively 4:
- Three of seven conservatively treated undisplaced fractures required delayed internal fixation for symptomatic nonunion 4
- However, delayed fixation (up to 8 weeks) does not appear to adversely affect outcomes 4
Conservative Treatment (Round Fragments)
Conservative treatment is effective if the fragment is round because the articular surface is not involved 1:
- Treat with buddy taping (neighbor strapping) and early active mobilization 5
- This approach is successful for fragments between 10-25% of the articular surface width 5
- Mean DASH score of 3.1 and mean pain score of 0.6/10 at 57-month follow-up 5
- All but one patient achieved normal grip strength and full range of motion 5
Immobilization and Splinting
- Use rigid immobilization with a hand-based functional splint that allows MCP, interphalangeal, and radiocarpal joint motion 3, 6
- The splint should be padded and comfortably tight but not constrictive (should allow a finger to slip under it) 7
- Stabilize in the position found without attempting to straighten the fracture 2, 7
- Average splint duration is approximately 24 days for stable fractures 6
Rehabilitation Protocol
Initiate active finger motion exercises immediately to prevent stiffness 3, 7:
- Regular movement through complete range of motion minimizes hand stiffness, the most functionally disabling complication 7
- Finger motion does not adversely affect adequately stabilized fractures 7
- For surgically treated cases, gentle mobilization can begin early post-fixation 4
Follow-up Care
- Obtain radiographic follow-up at approximately 3 weeks and at cessation of immobilization 8, 3, 7
- Monitor for signs of nonunion, particularly in conservatively treated cases with articular involvement 4
- Symptomatic nonunion requires delayed surgical fixation 9, 4
Critical Pitfall
The avulsed fragment often overlaps the metacarpal head, and collateral ligament injury is frequently misdiagnosed 1. It is essential to assess the shape of the entire fragment on radiographs to determine appropriate treatment and achieve good functional results 1.