Treatment of MCP Joint Fracture of the Third Digit
For fractures at the metacarpophalangeal joint of the third digit, surgical fixation with open reduction and internal fixation is recommended when articular involvement exceeds 20% or displacement is greater than 1-2 mm; otherwise, rigid immobilization is appropriate. 1
Initial Assessment and Imaging
- Obtain a minimum 2-view radiographic examination (PA and lateral), though a standard 3-view examination (PA, lateral, and oblique) is preferred for complete hand evaluation 2
- Evaluate for obvious deformity, swelling, bruising, severe pain with movement, or inability to move the affected digit 3
- Assess the degree of articular involvement and fragment displacement on radiographs 1
Treatment Algorithm
Indications for Surgical Fixation
Operative treatment is indicated when:
- Articular involvement exceeds 20% 1
- Displacement is greater than 1-2 mm 1
- Open fractures are present 3
- The fracture fragment is triangular or rectangular in shape (indicating articular surface involvement) 4
Non-Operative Management
Conservative treatment is appropriate when:
- Articular involvement is less than 20% and displacement is minimal (≤1-2 mm) 1
- The fracture fragment is round in shape (indicating no articular surface involvement) 4
- No joint instability is present 5
For non-operative cases:
- Apply rigid immobilization with splinting rather than removable splints 3
- Immobilize for 3-4 weeks duration 6
Critical Surgical Considerations
- MCP joints tolerate fracture involvement and displacement better than PIP joints, but precise reduction remains important 1
- A dorsal surgical approach is often necessary for complex fracture-dislocations, as volar approaches may be inadequate for proper reduction and fixation 7
- Assess for collateral ligament injury, which can be misdiagnosed when the avulsed fragment overlaps the metacarpal head 4
- Interposed volar plate may require longitudinal incision and repositioning to achieve anatomic reduction 7
Rehabilitation Protocol
- Initiate active finger motion exercises immediately following stable fixation to prevent stiffness 2, 6
- Early finger motion does not adversely affect adequately stabilized fractures 6
- Include muscle strengthening exercises in the rehabilitation program 3
- Continue long-term hand exercises 3
Follow-Up and Monitoring
- Obtain radiographic follow-up at approximately 3 weeks post-immobilization 3, 6
- Additional imaging at the time of immobilization removal to confirm adequate healing 3, 6
- Monitor for signs of complications including chronic instability, subsequent arthritis, or functional limitations 5
- Seek immediate emergency care if the fractured digit appears blue, purple, or pale 3
Common Pitfalls to Avoid
- Do not miss collateral ligament injuries when avulsion fragments overlap the metacarpal head 4
- Assess the complete shape of the fragment on radiographs, as partial visualization may lead to incorrect treatment decisions 4
- Incorrect or absent diagnostics can result in chronic instability, dislocation, fusion, and substantial impairment of gripping function 5
- Attempted closed reduction may be unsuccessful in complex fracture-dislocations requiring open surgical intervention 7