How long should I wear a walking boot for a base fifth metatarsal fracture?

Management of Base Fifth Metatarsal Fractures: Duration of Walking Boot Use

For a base fifth metatarsal fracture, a walking boot should typically be worn for 4-6 weeks, with progressive weight-bearing as tolerated based on pain levels and radiographic healing.

Initial Assessment and Diagnosis

• Fifth metatarsal fractures are among the most common foot fractures, often resulting from twisting forces or crush injuries 1
• Diagnosis should follow the Ottawa Ankle Rules to determine the need for imaging 2
• Standard three-view radiographs (anteroposterior, lateral, and mortise) should include the base of the fifth metatarsal 2
• Weight-bearing radiographs provide important information about fracture stability 2

Types of Fifth Metatarsal Base Fractures

There are different types of fifth metatarsal base fractures, which affect treatment duration:

1. Avulsion fractures (most common): Occur at the tuberosity of the fifth metatarsal
2. Jones fractures: Occur at the metaphyseal-diaphyseal junction
3. Shaft fractures: Occur in the diaphyseal region

Treatment Duration Guidelines

Avulsion Fractures

• Initial treatment: Compressive dressing
• Transition to walking boot for 2-4 weeks 3
• Progressive mobility as tolerated after initial immobilization
• Total healing time: Approximately 6-8 weeks

Jones Fractures

• Higher risk of nonunion due to poor blood supply
• Require 6-8 weeks in a short leg non-weight-bearing cast or boot 3
• Healing time can extend to 10-12 weeks in some cases
• May require surgical intervention if displacement is significant

Metatarsal Shaft Fractures

• Walking boot or cast for 4-6 weeks 4, 3
• Weight-bearing based on fracture stability and pain levels

Evidence for Walking Boot vs. Cast

A comparative cohort study showed that patients treated with walking boots:

• Experienced less pain between 3-12 weeks compared to short-leg casts 5
• Had significantly better function at 3,6, and 9 weeks 5
• Returned to pre-injury function level at approximately 9 weeks (vs. 12 weeks with cast) 5
• Returned to driving earlier (6 weeks vs. 12 weeks with cast) 5
• Took fewer days off work (31.5 days vs. 39.2 days with cast) 5

Weight-Bearing Progression

1. Initial phase (0-2 weeks):

   • Limited weight-bearing with assistive devices as needed
   • PRICE protocol (Protection, Rest, Ice, Compression, Elevation)

2. Intermediate phase (2-4 weeks):

   • Progressive weight-bearing as tolerated in the walking boot
   • Begin gentle range of motion exercises if pain allows

3. Late phase (4-6+ weeks):

   • Full weight-bearing in boot
   • Transition to regular supportive footwear as tolerated
   • Begin strengthening and proprioceptive exercises

Monitoring and Follow-up

• Regular follow-up with radiographs to assess healing
• Monitor for complications such as nonunion, malunion, or persistent pain
• Consider longer immobilization if radiographic healing is delayed

Return to Activities

• Return to normal footwear: 4-6 weeks for avulsion fractures, 8-12 weeks for Jones fractures
• Return to sports/high-impact activities: 10-12 weeks for avulsion fractures, 12-16 weeks for Jones fractures
• Consider proprioceptive exercises and ankle bracing during high-risk activities to prevent recurrence 6

Special Considerations

• Diabetic patients and those with peripheral vascular disease require careful monitoring due to higher complication risks 6
• Displaced fractures (>2mm) or those involving >30% of the joint surface may require surgical fixation 4
• Early functional treatment with a walking boot has shown good outcomes with no complications in long-term follow-up 7

A walking boot provides better outcomes than a cast for most fifth metatarsal base fractures, with faster return to function and less pain during recovery 5.