What is the initial management for a fracture at the base of the 5th metatarsal?

Initial Management of Base of 5th Metatarsal Fractures

For acute base of 5th metatarsal fractures, immobilize immediately with a short CAM walker boot, which provides superior offloading compared to other devices and allows for early weight-bearing as tolerated. 1, 2

Immediate Splinting and Immobilization

Initial Device Selection

• Apply a short controlled ankle motion (CAM) walker boot as the preferred immobilization device 1, 2
• 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 standard shoes 2
• This device allows full weight-bearing within approximately 9 days while maintaining adequate fracture protection 3

Alternative Immobilization Options

• Hard-soled shoes (HSS) are an acceptable alternative for zone 1 (tuberosity avulsion) fractures, though bone healing occurs slightly slower (8.6 weeks vs 7.2 weeks with CAM boot) 4
• Soft (Jones) dressings with compressive wrapping allow faster return to activity (33 days average) compared to short leg casts (46 days average) for avulsion fractures 5
• Avoid rigid short leg casts as primary treatment—they delay return to function without improving outcomes 5

Fracture-Specific Treatment Protocols

Zone 1 (Tuberosity Avulsion Fractures)

• Begin with compressive dressing acutely, then transition to short leg walking boot for 2 weeks 6
• Progress to weight-bearing as tolerated after initial immobilization 1, 6
• Expected healing time: 7-9 weeks 4

Zone 2 (Jones Fractures - Metaphyseal-Diaphyseal Junction)

• Requires more aggressive immobilization due to high nonunion risk 6
• Use short leg non-weight-bearing cast for minimum 6-8 weeks 6
• Healing time extends to 10-12 weeks in many cases 6
• Consider early surgical consultation for athletes or those requiring faster return to activity 6

Weight-Bearing Progression

• Allow progressive weight-bearing as tolerated after initial immobilization period for zone 1 fractures 1, 7
• Full weight-bearing typically achieved within 9 days when using CAM walker boot 3
• Zone 2 (Jones) fractures require strict non-weight-bearing for 6-8 weeks 6

Pain Management During Immobilization

• Splinting immediately reduces pain and prevents further injury during transport 8
• Early fracture stabilization through proper immobilization provides the most effective analgesia 9
• Cover any open wounds with clean dressing before splinting to reduce contamination risk 8

Critical Assessment Points

Vascular Status

• Check for blue, purple, or pale appearance of the foot—this indicates poor perfusion requiring immediate medical attention 8
• Assess capillary refill and distal pulses before and after splint application

Radiographic Confirmation

• Obtain three standard views (anteroposterior, lateral, and mortise) that specifically include the base of the 5th metatarsal 1, 7
• Weight-bearing radiographs provide crucial stability information when patient can tolerate them 1, 7
• Common pitfall: failing to include the 5th metatarsal base in ankle radiographs leads to missed fractures 7

Special Population Considerations

• Patients with diabetes and neuropathy require special attention to offloading to prevent complications 1, 8
• Monitor preadolescent patients for hypothermia if ice is applied to associated soft tissue injuries 8

Follow-Up and Rehabilitation

• Regular radiographic assessment ensures proper healing and alignment 1, 7
• Introduce early physical training and muscle strengthening followed by balance training after immobilization 1, 7
• Avoid prolonged immobilization beyond necessary timeframes—this causes stiffness and muscle atrophy 1, 7
• Average return to prior activity levels: 8-10 weeks for zone 1 fractures 4