What is the recommended treatment for a fifth metatarsal metaphysis fracture?

Treatment of Fifth Metatarsal Metaphysis Fractures

For fifth metatarsal metaphysis fractures, non-operative treatment with a CAM walker boot and weight-bearing as tolerated is recommended as the primary treatment approach, showing faster bone healing compared to hard-soled shoes. 1

Classification and Diagnosis

• Fifth metatarsal fractures are classified based on anatomical location:

  • Zone 1: Avulsion fractures at the base (tuberosity)
  • Zone 2: Metaphyseal-diaphyseal junction fractures (Jones fractures)
  • Zone 3: Proximal diaphyseal fractures

• Diagnosis requires:

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

Treatment Algorithm

Non-displaced or Minimally Displaced Metaphysis Fractures

1. First-line treatment: CAM walker boot with weight-bearing as tolerated for 6-8 weeks 1

   • Provides better outcomes than short-leg casts
   • Results in faster bone healing (7.2 weeks vs 8.6 weeks for hard-soled shoes) 3
   • Leads to better early foot function scores compared to casts 4

2. Follow-up schedule:

   • Clinical and radiographic assessment at 2,6, and 12 weeks
   • Progressive weight-bearing based on clinical and radiographic healing
   • Return to prior activity levels typically around 8-10 weeks 1

Displaced Metaphysis Fractures

1. Surgical indications:

   • Displacement >2mm
   • Fractures involving >30% of cubometatarsal joint
   • Intra-articular involvement 1, 5

2. Surgical options:

   • For shaft/neck fractures: Open reduction and internal fixation with plate and screws 6
   • For transverse fractures: Percutaneous pinning with Kirschner wires 6
   • For avulsion fractures: Tension-band wiring or screw fixation if displaced >2mm 7

Special Considerations

• Athletic patients: May benefit from early surgical fixation with intramedullary screw for faster return to sports 1

• Non-union cases: Tension-band wiring has shown good results in cases where prior non-operative or operative treatment failed, with mean time to union of 12.8 weeks 7

• Post-surgical protocol:

  • Rest, elevation, and local cooling initially
  • Partial weight-bearing (20 kg) in foot orthosis or cast shoe for 6 weeks 6
  • Return to sports may take 10-14 weeks for surgically treated fractures 1

Pitfalls and Caveats

• Avoid using conventional or standard therapeutic footwear without proper offloading devices, as this may delay healing 2

• Be vigilant for signs of delayed union or non-union, particularly in fractures at the metaphyseal-diaphyseal junction, which have a higher tendency for these complications 5

• For patients with diabetes and neuropathy who develop ulcers, different offloading approaches may be needed, including total contact casts or non-removable knee-high walkers 2

• Do not confuse avulsion fractures of the fifth metatarsal (which generally heal well with conservative treatment) with Jones fractures at the metaphyseal-diaphyseal junction (which have higher non-union rates) 5