What is the typical treatment for a 5th metatarsal fracture?

Treatment of 5th Metatarsal Fractures

The standard treatment for a 5th metatarsal fracture depends on the fracture type, with non-displaced or minimally displaced fractures typically managed non-operatively using a CAM walker boot with weight-bearing as tolerated, while displaced fractures (>2mm) or those involving >30% of the cubometatarsal joint require surgical fixation. 1

Classification and Diagnosis

The approach to treatment begins with proper classification of the fracture:

• Zone 1: Avulsion fractures at the tuberosity (most common)
• Zone 2: Jones fractures at the metaphyseal-diaphyseal junction
• Zone 3: Diaphyseal stress fractures (proximal shaft)

Diagnosis requires:

• Standard three radiographic views: anteroposterior, lateral, and mortise 1
• MRI may be considered if radiographs are negative but clinical suspicion remains high 2, 1

Treatment Algorithm

Non-operative Treatment

• Indicated for:

  • Non-displaced or minimally displaced tuberosity avulsion fractures
  • Shaft fractures with <3-4mm displacement and <10° angulation 3
  • Type I Jones fractures (acute fractures with sharp margins and no intramedullary sclerosis) 1

• Method:

  • CAM walker boot is the preferred device, showing significantly lower peak pressure and contact pressure at the fifth metatarsal during walking compared to postoperative sandals or athletic shoes 4
  • CAM walker boots demonstrate faster bone healing (7.2 weeks) compared to hard-soled shoes (8.6 weeks) 5
  • Weight-bearing as tolerated is recommended 1

Surgical Treatment

• Indicated for:

  • Fractures displaced >2mm 3
  • Fractures involving >30% of the cubometatarsal joint 1, 3
  • Shaft fractures with >3-4mm displacement or >10° angulation 3
  • Type II Jones fractures (delayed union) in athletic patients 1
  • All Type III Jones fractures (non-union with medullary sclerosis) 1

• Methods:

  • Intramedullary screw fixation (most common for Jones fractures)
  • Percutaneous K-wires
  • Plate fixation for comminuted fractures

Special Considerations

Athletic Patients

• Athletic patients may benefit from early surgical fixation with an intramedullary screw for faster return to sports 1
• Return to sports typically takes 10-14 weeks after surgical treatment 1

High-Risk Fractures

• Fifth metatarsal base fractures are considered high-risk stress fractures 2
• These fractures require careful monitoring due to potential for delayed union or non-union

Follow-up and Rehabilitation

• Clinical and radiographic assessment at 2,6, and 12 weeks 1
• Progressive weight-bearing based on clinical and radiographic healing
• Return to prior activity levels typically occurs around 8-10 weeks for conservatively treated fractures 1
• Bone healing typically occurs within 7-8 weeks 1

Common Pitfalls to Avoid

1. Misdiagnosis: Failing to distinguish between different zones of fracture, which require different treatment approaches
2. Inadequate immobilization: Using conventional footwear without proper offloading devices may delay healing 1
3. Missed follow-up: While some studies suggest routine follow-up may not be necessary for all fifth metatarsal fractures 6, high-risk patterns should be monitored closely
4. Delayed surgical intervention: Delaying surgery for displaced fractures or Jones fractures in athletes may lead to non-union or prolonged recovery

The CAM walker boot has demonstrated superior outcomes in terms of offloading the fifth metatarsal and promoting faster bone healing compared to other conservative options, making it the preferred non-operative treatment device 4, 5.