What is the treatment for a comminuted metatarsal fracture?

Treatment of Comminuted Metatarsal Fractures

For comminuted metatarsal fractures, treatment depends critically on fracture location and stability: stable fractures require immobilization with buddy taping or rigid splinting for 3-6 weeks, while unstable or significantly displaced comminuted fractures mandate open reduction and internal fixation (ORIF) with mini-plates or screws to restore anatomical alignment and prevent long-term disability. 1, 2

Initial Assessment and Imaging

• Begin with standard three-view radiographs (anteroposterior, lateral, and oblique) to establish the diagnosis and assess fracture pattern 3, 4
• Order CT imaging for all comminuted fractures to fully evaluate the extent of comminution, intra-articular involvement, and guide surgical planning 3, 1
• CT is particularly critical because radiographs have poor sensitivity (25-33%) for detecting the true extent of midfoot fractures 3
• Consider MRI if there is concern for associated soft-tissue injuries, ligamentous disruption, or occult fractures not visible on CT 3

Treatment Algorithm Based on Fracture Characteristics

Non-Displaced or Minimally Comminuted Fractures

• Immobilize with rigid splinting or buddy taping to an adjacent uninjured toe with padding between toes to prevent skin maceration 1
• The splint must extend beyond the fracture site to include adjacent joints for adequate stability 1
• Maintain immobilization for 3-6 weeks until clinical and radiographic evidence of healing 1
• Obtain radiographic follow-up at approximately 3 weeks to assess healing progress 1

Displaced or Unstable Comminuted Fractures

• Proceed with ORIF using mini-plates via appropriate surgical approach 2
• For first metatarsal shaft comminuted fractures, use a medial approach with mini-plate fixation to achieve full exposure and anatomical reduction 2
• For fifth metatarsal zone 2 (Jones) fractures with minimal comminution, percutaneous intramedullary screw fixation (4.5-5.5mm full-core screw) is preferred 5
• Note: Percutaneous screw fixation is contraindicated for severely comminuted fractures or proximal-split patterns - these require plate fixation instead 5

Severely Comminuted Fractures with Bone Loss

• In cases of significant bone and soft-tissue destruction not amenable to standard fixation, consider vascularized free fibular osteocutaneous flap reconstruction to avoid proximal amputation 6
• This advanced technique is reserved for high-energy traumatic injuries with substantial metatarsal bone defects 6

Special Considerations for Specific Metatarsal Locations

First Metatarsal Comminuted Fractures

• Anatomic reduction and stable internal fixation are critical for restoring foot form and arch function 2
• Use mini-plate fixation via medial approach for optimal exposure and cosmetic results 2
• Expected bone union occurs at mean 11.5 weeks (range 10-14 weeks) 2

Fifth Metatarsal Zone 2 Fractures

• Surgical management leads to significantly higher union rates (89-100%) compared to nonoperative treatment (70-85% union rate) 5
• The retrograde vascular supply to zone 2 creates a watershed region with high nonunion risk (15-30%) if treated nonoperatively 5
• For acute Jones fractures with minimal comminution, intramedullary screw fixation achieves 100% union rates 5

Second Metatarsal Base Comminuted Fractures with Lisfranc Injury

• Use Kirschner wire fixation from medial cuneiform to second metatarsal base to stabilize the Lisfranc ligament while avoiding arthrodesis 7
• This approach is particularly important when comminution involves the base of the second metatarsal 7

Postoperative Management Protocol

Weeks 0-2

• Non-weight-bearing in soft wrap and postoperative boot 5
• Keep incision clean and dry with frequent elevation 5
• Begin ankle range-of-motion exercises 5

Weeks 2-6

• Remove sutures at 2-6 weeks 5
• Progressive weight-bearing: 25% at week 3,50% at week 4,75% at week 5,100% at week 6 5
• Continue boot for all weight-bearing ambulation with crutches for transition 5

Weeks 6-12

• Expect radiographic union between weeks 6-10 5
• Increase walking and physical therapy 5
• Begin pool or treadmill activity at weeks 8-12 5

Critical Pitfalls to Avoid

• Do not use percutaneous screw fixation for severely comminuted fractures - this will fail and requires plate fixation instead 5
• Do not undertighten immobilization devices, but equally avoid overtightening compression wraps which can compromise circulation 1
• Do not delay CT imaging - standard radiographs miss 67-75% of the true extent of comminuted midfoot fractures 3
• Do not allow immediate weight-bearing postoperatively - this increases risk of fixation failure and nonunion 5
• For fractures with sclerotic margins or chronic nonunion, fenestrate fracture edges and add bone grafting before screw insertion 5