What is the recommended treatment for a fifth metatarsal fracture?

Management of Fifth Metatarsal Fractures

For fifth metatarsal fractures, a CAM walker boot with weight-bearing as tolerated is the recommended treatment, showing faster bone healing compared to hard-soled shoes while providing similar clinical outcomes. 1, 2

Diagnosis

• The Ottawa Ankle Rules should be used to determine the need for radiographs in acute foot trauma 3:

  • Point bone tenderness at the base of the fifth metatarsal
  • Inability to bear weight or walk 4 steps immediately after injury
  • Pain in the midfoot

• Standard three radiographic views are required for proper diagnosis:

  • Anteroposterior
  • Lateral
  • Mortise views

Classification and Treatment Approach

Zone 1 Fractures (Avulsion Fractures at Base)

• Treatment: CAM walker boot with weight-bearing as tolerated
• Evidence: Studies show faster bone healing (7.2 weeks) with CAM walker boot compared to hard-soled shoes (8.6 weeks) 1
• Advantage: CAM walker boot more effectively offloads the fifth metatarsal during common gait activities 4
• Duration: Typically 6-8 weeks of protection

Zone 2 Fractures (Jones Fractures)

• Non-athletic patients: Non-weight-bearing in a CAM walker boot for 6-8 weeks 2
• Athletic patients: Consider early surgical fixation with intramedullary screw for faster return to sports 2

Zone 3 Fractures (Diaphyseal Stress Fractures)

• Treatment: Surgical fixation typically recommended due to high non-union rates 2

Displaced Fractures

• Indication for surgery: Displacement >2mm or involving >30% of the joint surface 5
• Method: Internal fixation with screws or tension-band wiring

Follow-up Protocol

Interestingly, routine follow-up may not be necessary for most fifth metatarsal fractures. A study showed no added clinical value for routine outpatient follow-up when patients are:

• Provided with appropriate information
• Given access to a help-line for concerns
• Instructed to weight-bear as tolerated with proper support 6

Expected Recovery Timeline

• Bone healing: 7-8 weeks on average 2, 1
• Return to prior activities:
  • CAM walker boot: 8.3 weeks
  • Hard-soled shoe: 9.7 weeks 1
• Return to sports: 10-14 weeks for surgically treated fractures 2

Pitfalls to Avoid

1. Inadequate immobilization: Using conventional footwear without proper offloading can delay healing
2. Missing associated injuries: Always evaluate for other midfoot injuries
3. Failure to recognize displaced fractures: Displacement >2mm may require surgical intervention
4. Overlooking stress fractures: These may not be visible on initial radiographs and may require MRI for diagnosis

Special Considerations

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

The evidence strongly supports the use of CAM walker boots for fifth metatarsal fractures, as they provide better pressure offloading at the fifth metatarsal base compared to postoperative sandals or athletic shoes 4, resulting in faster bone healing while maintaining similar functional outcomes 1.