Treatment of Persistent Metatarsal Fractures
For persistent metatarsal fractures, surgical fixation is recommended when there is postreduction radial shortening >3 mm, dorsal tilt >10°, or intra-articular displacement, as these factors indicate instability that may lead to poor healing and functional outcomes. 1
Initial Assessment and Treatment Options
Conservative Management
- Most metatarsal fractures that are nondisplaced or minimally displaced can be treated conservatively with protected weight bearing in a cast shoe for 4-6 weeks 2
- For acute fifth metatarsal tuberosity fractures (Zone 1), conservative treatment with either a hard-soled shoe or a controlled ankle motion (CAM)-walker boot shows good results, with CAM-walker boots demonstrating faster bone healing (7.2 weeks vs 8.6 weeks) 3
- Conservative treatment typically includes:
- Immobilization with appropriate footwear or casting for 2-3 weeks
- Gradual increase in activity and strengthening until clinical union is achieved 4
Surgical Intervention
- Surgical fixation should be considered for:
- Fractures with postreduction radial shortening >3 mm
- Fractures with dorsal tilt >10°
- Fractures with intra-articular displacement 1
- Percutaneous pinning is suitable for most fractures of the lesser metatarsals 2
- K-wire intramedullary nailing shows better outcomes compared to open reduction and internal fixation, with:
- Shorter healing time (approximately 6.5-7.4 weeks vs 10.9 weeks)
- Earlier weight bearing and quicker rehabilitation 5
Special Considerations for Different Fracture Types
Fifth Metatarsal Fractures
- Zone 1 fractures (tuberosity) generally respond well to conservative treatment 4
- Transverse fractures at the metaphyseal-diaphyseal junction ("Jones fractures") require an individualized approach based on activity level and time to union 2
- Avulsion fractures of the fifth metatarsal require open reduction and tension-band wiring or screw fixation if displaced more than 2 mm or with more than 30% joint involvement 2
Persistent/Non-healing Fractures
- For persistent fractures, especially in zones 2 and 3 of the fifth metatarsal (high-risk group for delayed union):
- Consider immobilization boot combined with nutritional supplements (calcium and vitamin D)
- Platelet-rich plasma injections may be beneficial in promoting healing 6
Special Considerations for Patients with Diabetes
- Proper fitting of orthotic devices is essential to prevent pressure sores and complications such as ulceration at the fracture site 7, 8
- Special attention to offloading is required to prevent ulceration, with focus on proper wound care and management 7, 8
- For diabetic patients with neuropathic plantar metatarsal head ulcers where non-surgical offloading fails:
- Consider Achilles tendon lengthening in combination with an offloading device
- Metatarsal head resection may be necessary when osteomyelitis or infection in the metatarsophalangeal joint is identified 8
Monitoring and Follow-up
- Regular radiographic assessment to monitor fracture healing
- Functional assessment using validated tools like the American Orthopaedic Foot & Ankle Society (AOFAS) score
- Gradual return to activities based on clinical and radiographic evidence of healing 3
Pitfalls and Caveats
- Malunited metatarsal fractures can be a frequent source of pain and disability if not properly managed 2
- Stress fractures of the metatarsals are common and typically treated nonoperatively, but require adequate rest and protected weight bearing 2
- Symptomatic posttraumatic deformities may need correction, usually by osteotomy across the former fracture site 2
- Avoid premature return to high-impact activities before complete healing, as this may lead to refracture or nonunion