Conservative Versus Surgical Management of Fifth Metatarsal Avulsion Fractures

Fifth metatarsal avulsion fractures are among the most common fractures seen by foot and ankle surgeons. Studies have centered around classification systems, but debate continues regarding surgical versus conservative treatment modalities. The present study focused on quantifying the time for healing fifth metatarsal base avulsion fractures. Specifically, we compared healing time, displacement, and incidence of nonunion among surgically managed and conservatively managed avulsion fractures. Surgically managed patients underwent either open reduction with internal fixation or closed reduction with percutaneous fixation. Conservatively managed fractures were immobilized with a below-knee cast or pneumatic walking boot. Fifty-one patient records (51 feet) were retrospectively compared for basic demographics, smoking, and diabetes status, presence of peripheral neuropathy, Stewart classification, amount of displacement, rate of nonunion, and radiographic healing time. The groups did not differ significantly based on age, sex, or the remaining clinical characteristics including time to consolidation. However, among the 31 conservatively managed patients, 11 (35.5%) developed an asymptomatic nonunion versus none among the 20 patients treated surgically (p = .004). All patients were asymptomatic at 1 year. This study provides insight into the time required for fifth metatarsal avulsion fractures to heal or become asymptomatic. The surgical management of these fractures helped to eliminate the risk of nonunion and helped ensure a timely return to preinjury activity. We recommend surgical management of any fifth metatarsal avulsion fracture displaced >2 mm. Both patients and physicians should have realistic expectations when making decisions regarding treatment modalities for fifth metatarsal avulsion fractures.