What is the treatment for a displaced fracture of the left 5th metatarsal?

Treatment of Displaced Fracture of the Left 5th Metatarsal

For displaced fractures of the 5th metatarsal, internal fixation is the recommended treatment to restore anatomical alignment, ensure proper healing, and improve functional outcomes.

Classification and Assessment

Before determining the specific treatment approach, it's important to classify the fracture:

1. Tuberosity (base) fractures - Most common, typically avulsion injuries
2. Jones fractures - At the metaphyseal-diaphyseal junction
3. Shaft/neck fractures - Distal to the tuberosity
4. Displaced vs. non-displaced - Degree of displacement affects treatment decisions

Treatment Algorithm for Displaced 5th Metatarsal Fractures

Surgical Indications

• Significant displacement (>3mm)
• Intra-articular involvement
• Comminution
• Rotational deformity
• Shortened metatarsal

Surgical Options Based on Fracture Location

1. Displaced Tuberosity (Base) Fractures

• Preferred technique: Open reduction and internal fixation with:
  • Lag screws or K-wires for larger fragments 1
  • Suture anchor fixation for avulsion fractures 2
  • Three-wire fixation technique for comminuted fractures 1

2. Displaced Jones Fractures

• Preferred technique: Intramedullary lag screw fixation
  • Particularly important in active or athletic patients 3
  • Higher union rates with surgical treatment

3. Displaced Shaft/Neck Fractures

• Preferred technique: Open reduction with plate fixation
  • Interlocking plates with 2.0-2.4mm screws to avoid soft tissue irritation 4
  • For long spiral fractures, screw fixation may be sufficient
  • For transverse or subcapital fractures, percutaneous K-wire fixation is an option 4

Surgical Approach

• Lateral approach above the glabrous skin of the sole
• Anatomic reconstruction under longitudinal traction
• Temporary K-wire fixation may be used during reduction
• Interfragmentary lag screws for compression when fragments are large enough 4

Postoperative Management

1. Initial phase (0-2 weeks):

   • Rest, elevation, and local cooling
   • Non-weight bearing or partial weight bearing (20kg) in protective footwear

2. Intermediate phase (2-6 weeks):

   • Partial weight bearing in foot orthosis or cast shoe
   • Regular wound checks and radiographic evaluation

3. Final phase (6+ weeks):

   • Progressive weight bearing as tolerated
   • Return to activities based on radiographic evidence of healing

Prognosis and Complications

• Even grossly displaced fractures have good to excellent prognosis following surgical treatment 4
• High union rates with appropriate fixation
• Potential complications include:
  • Hardware irritation
  • Nonunion (rare with proper fixation)
  • Refracture (particularly with Jones fractures)

Special Considerations

• For high-risk patients (elderly, poor bone quality), consider risk-benefit analysis of surgery versus conservative management
• In athletes or highly active individuals, surgical fixation may allow earlier return to activities 3
• For established nonunion cases, bone grafting may be necessary 3, 5

The choice of fixation method should be based on fracture pattern, location, and patient factors, but internal fixation remains the standard of care for displaced 5th metatarsal fractures to restore proper foot biomechanics and function.