What is the treatment for an oblique fracture of the metacarpal?

Treatment of Oblique Metacarpal Fractures

For oblique metacarpal fractures, most cases can be managed nonoperatively, while displaced unstable fractures require surgical fixation with either percutaneous Kirschner wires or internal fixation methods depending on fracture characteristics. 1

Diagnostic Approach

• Initial evaluation should include standard radiographs (3 views) of the hand to assess:
  • Fracture pattern and displacement
  • Angulation and rotation
  • Articular involvement
  • Associated injuries 2
• If radiographs are equivocal, CT without IV contrast may be considered to better visualize fracture morphology 2

Treatment Algorithm

1. Nonoperative Management (First-line for stable fractures)

• Indicated for:
  • Non-displaced or minimally displaced fractures
  • Stable fractures with acceptable alignment
• Treatment consists of:
  • Immobilization with a short arm cast or splint for 3-4 weeks 3
  • Appropriate pain management with NSAIDs 3
  • Early rehabilitation after immobilization period

2. Surgical Management (For unstable/displaced fractures)

• Indications for surgery:
  • Unstable fractures
  • Significant displacement or angulation
  • Rotational deformity
  • Multiple fractures

Surgical Options:

1. Percutaneous Kirschner wires (K-wires)

   • Most commonly used due to versatility and availability
   • Suitable for most unstable fractures
   • Limitations: lack of rigid fixation, risk of pin track infection 4

2. Interfragmentary screw fixation

   • Indicated for large oblique fractures
   • Options include:
     • Lag screw technique
     • Bicortical interfragmentary screws (equally effective as lag screws) 5
   • Provides stable fixation allowing early mobilization

3. Plate fixation

   • Limited indications: multiple unstable shaft or complex oblique fractures 1
   • Provides rigid fixation but plates can be bulky

4. Cerclage wire fixation

   • Effective for long oblique/spiral mid-shaft metacarpal fractures
   • Allows immediate postoperative finger mobilization 6

5. Intramedullary fixation

   • Recent evidence shows superior biomechanical stability compared to K-wires for oblique metadiaphyseal fractures
   • Provides higher load to failure and stiffness 7

Rehabilitation Protocol

• After immobilization period (typically 3-4 weeks):
  • Progressive range of motion exercises
  • Directed home exercise program
  • Balance training and fall prevention 3
• Full recovery typically expected within 6-8 weeks 3

Special Considerations

• Monitor for complications:
  • Malunion
  • Stiffness
  • Rotational deformity
  • Infection (with surgical management)
• Smoking increases nonunion risk and leads to inferior outcomes 3
• Patient education on proper immobilization device use is crucial for optimal recovery 3

Common Pitfalls to Avoid

1. Inadequate radiographic assessment (always obtain at least 3 views)
2. Missing rotational deformity (assess finger cascade)
3. Prolonged immobilization leading to stiffness
4. Inadequate fixation of unstable fractures
5. Failure to initiate early rehabilitation after the immobilization period

The most recent evidence suggests that noncompressive intramedullary fixation provides biomechanically superior constructs for oblique metacarpal fractures compared to traditional crossed K-wire fixation, potentially allowing for earlier range of motion 7.