What are the guidelines for managing a 5th metacarpal fracture?

Management Guidelines for 5th Metacarpal Fracture

The treatment of 5th metacarpal fractures should be based on fracture characteristics, with non-displaced fractures managed conservatively through functional taping or splinting, while displaced fractures with >70 degrees angulation require surgical intervention.

Assessment and Classification

• Evaluate:
  • Fracture location (neck, shaft, base)
  • Displacement (acceptable if <2-3mm step-off)
  • Angulation (acceptable up to 70 degrees for neck fractures)
  • Rotation (any rotational deformity requires correction)
  • Neurovascular status
  • Integrity of extensor mechanism

Treatment Algorithm

Conservative Management

• Indicated for:

  • Closed fractures
  • Non-displaced or minimally displaced fractures
  • Angulation <70 degrees
  • No rotational deformity
  • Intact neurovascular status

• Treatment options:

  • Functional taping: Provides quicker functional recovery compared to plaster casting 1
  • Buddy strapping with Futura splint: Good functional outcomes for minimally displaced fractures 2
  • Ulnar gutter splint: Alternative for pain control in the acute phase

Surgical Management

• Indicated for:

  • Open fractures
  • Angulation >70 degrees
  • Rotational deformity
  • Significant displacement (>2-3mm)
  • Intra-articular fractures with displacement
  • Neurovascular compromise

• Surgical options:

  • Closed reduction and percutaneous K-wire fixation: First-line surgical approach for most displaced fractures 3
  • Open reduction and internal fixation (ORIF): For comminuted fractures or when closed reduction fails 3
  • Plate and screw fixation: Reserved for cases with significant comminution or multiple metacarpal fractures 2

Rehabilitation Protocol

• For conservative management:

  • Begin early mobilization if using functional taping 4, 1
  • If using splint, maintain for 3-4 weeks

• For surgical management:

  • Begin early finger motion to prevent edema and stiffness 5
  • When immobilization is discontinued, aggressive finger and hand motion is necessary 5
  • K-wires typically removed at 4-6 weeks

Follow-up Schedule

• Initial follow-up at 1-2 weeks to:

  • Assess pain control
  • Check for displacement (if conservatively managed)
  • Evaluate finger motion

• Subsequent follow-up at 4-6 weeks to:

  • Confirm fracture healing
  • Remove hardware if applicable
  • Advance rehabilitation

Special Considerations

Base of 5th Metacarpal Fractures

• These fractures are inherently unstable and require careful management 3
• Intra-articular fractures of the base typically require surgical intervention to restore articular congruity 3, 6
• Carpometacarpal joint involvement may require specialized fixation techniques 6

Pathological Fractures

• For suspected pathological fractures, external splinting and pain control should be provided until diagnosis is established 5
• Internal fixation is contraindicated until pathology is ruled out 5

Complications to Monitor

• Malunion with functional deficit
• Stiffness and reduced range of motion
• Post-traumatic arthritis (especially with intra-articular fractures)
• Extensor lag

Pitfalls to Avoid

• Failing to assess rotational alignment (check by having patient flex fingers - they should point toward the scaphoid)
• Accepting excessive angulation in active patients with high functional demands
• Prolonged immobilization leading to stiffness
• Inadequate reduction of intra-articular fractures leading to post-traumatic arthritis

By following these guidelines, most patients with 5th metacarpal fractures can achieve good functional outcomes with minimal long-term disability.