Management of 5th Metatarsal Fractures with Walking Boot/CAM Boot
A walking boot (CAM boot) is the recommended treatment for 5th metatarsal fractures, providing superior offloading and immobilization compared to alternative devices. 1, 2
Treatment by Fracture Location
Zone 1 (Tuberosity Avulsion) Fractures
- Initiate treatment with a short leg walking boot for 2 weeks with progressive weight-bearing as tolerated 3
- The CAM walker boot significantly reduces peak pressure and contact pressure at the 5th metatarsal base during walking and heel-walking compared to postoperative sandals or athletic shoes 2
- Both CAM walker boots and hard-soled shoes achieve similar clinical outcomes, but the CAM boot demonstrates faster radiographic healing (7.2 weeks vs 8.6 weeks) 4
- After initial immobilization, transition to a rigid-sole shoe for continued protection 3
Zone 2 (Jones) Fractures
- Require at least 6-8 weeks in a short leg non-weight-bearing cast or boot due to high nonunion risk 3
- Healing time may extend to 10-12 weeks given the poor blood supply to this region 3, 5
- Early fracture stabilization through proper immobilization provides the most effective pain relief 6
Metatarsal Shaft Fractures
- Treat with a short leg walking boot or cast for 4-6 weeks 3, 5
- Initial treatment includes posterior splint with avoidance of weight-bearing activities 3
- Progressive weight-bearing as tolerated after the immobilization period 7
Key Clinical Advantages of CAM Walker Boot
- The CAM walker boot more effectively offloads the 5th metatarsal during common gait activities (walking, heel-walking, pivoting) than postoperative sandals or standard athletic shoes 2
- Provides adequate immobilization while allowing some mobility, which prevents complications of prolonged immobilization such as stiffness and muscle atrophy 6, 1
Critical Pitfalls to Avoid
- Do not use below-ankle offloading devices as primary treatment - they provide inadequate immobilization of the affected bones and joints 1
- Avoid premature return to high-impact activities before adequate healing to prevent nonunion or delayed healing 1
- For diabetic patients, ensure proper fitting of the boot to prevent pressure sores and monitor closely for skin breakdown or infection 7
Follow-Up and Rehabilitation
- Regular radiographic assessment is necessary to ensure proper healing and alignment 6
- After immobilization, introduce early physical training and muscle strengthening followed by long-term balance training 6
- Physical therapy may be beneficial to restore range of motion and strength 1
- Most patients can be safely discharged with structured advice and access to fracture clinic staff rather than routine follow-up, as nonunion rates remain low (approximately 1%) 8