What is the management of 3rd and 4th metacarpal fractures?

Management of 3rd and 4th Metacarpal Fractures

Most metacarpal fractures can be managed non-operatively with appropriate reduction and functional splinting, which allows for better maintenance of fracture reduction, early return to activities, and maintenance of functional motion throughout treatment. 1, 2

Initial Assessment and Imaging

• Standard radiographs (anteroposterior, lateral, and oblique views) are essential for diagnosis and assessment of fracture pattern, displacement, angulation, and rotation 3
• CT without IV contrast may be considered when initial radiographs are equivocal but clinical suspicion remains high 3
• MRI is usually not indicated during acute metacarpal fractures unless there is concern for associated soft tissue injuries 3

Treatment Algorithm

Non-operative Management (First-line for most cases)

Indications for non-operative treatment:

• Stable fractures
• Minimal displacement (<10 degrees angulation)
• No rotation
• No significant shortening

Non-operative treatment options:

1. Functional hand-based splinting (preferred):

   • Allows metacarpophalangeal joint, interphalangeal joint, and radiocarpal joint motion
   • Average splint duration: 3-4 weeks 2
   • Provides excellent maintenance of fracture reduction while allowing functional motion
   • Enables earlier return to activities compared to cast immobilization 2, 4

2. Alternative: Ulnar gutter splint/cast:

   • May be used for more unstable fractures
   • Typically maintained for 3-4 weeks
   • Results in slower functional recovery compared to functional taping 4

Operative Management

Indications for surgical intervention:

• Unstable fractures
• Significant angulation (>30° for 4th and 5th metacarpals, >10° for 2nd and 3rd metacarpals)
• Rotational deformity
• Significant shortening (>5mm)
• Multiple fractures
• Open fractures

Surgical options (in order of preference):

1. Closed reduction and percutaneous K-wire fixation:

   • Associated with less post-operative pain
   • Better range of motion (89.7° vs 80° for other methods)
   • Better grip strength (94% of normal vs 80-82% for other methods) 5
   • Preferred for most metacarpal fractures requiring fixation

2. Open reduction and internal fixation (ORIF):

   • With screws or plates
   • Consider for comminuted fractures or those with significant displacement
   • Associated with more post-operative pain and potentially more stiffness 5

Rehabilitation Protocol

1. Early finger motion:

   • Essential to prevent edema and stiffness
   • Should begin immediately after splinting/surgery 6

2. After splint/cast removal (3-4 weeks):

   • Begin weaning from the brace
   • Implement home exercise program focusing on active and passive range of motion exercises 6

3. Home exercise program:

   • As effective as supervised therapy for uncomplicated metacarpal fractures
   • Should include active motion exercises to prevent stiffness and promote full recovery 6

Follow-up

• Schedule follow-up with new x-rays at 3 months to assess healing 6
• Monitor for complications:
  • Joint stiffness
  • Malunion
  • Chronic pain
  • Post-traumatic arthritis

Special Considerations

• Pain management: NSAIDs are recommended for pain and inflammation control 6
• Smoking cessation: Advised as it increases nonunion rates and leads to inferior clinical outcomes 6
• Diabetic patients: Require close monitoring of skin to prevent pressure points and breakdown 6

Potential Complications

• Stiffness (most common)
• Malunion
• Nonunion (rare)
• Rotational deformity
• Post-traumatic arthritis

The evidence strongly supports that functional splinting with early mobilization provides better outcomes than rigid immobilization for most metacarpal fractures 2, 4. When surgical intervention is required, K-wire fixation appears to offer superior functional outcomes compared to screws or plates 5.