Nonoperative treatment of an os peroneum fracture in a high-level athlete: a case report.

BACKGROUND: The os peroneum is a sesamoid bone in the peroneus longus tendon. Fractures of the os peroneum are rare. Some authors recommend surgery for active patients. CASE DESCRIPTION: A 41-year-old male professional tennis coach sustained a minimally displaced fracture of the os peroneum. He was treated with restricted weightbearing for 2 weeks, followed by physical therapy and gradual return to activities. He returned to tennis 8 weeks after injury. Followup 7 years after the injury showed he had full strength, full motion, and a radiographically healed os peroneum. The American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale score was 100 and Ankle Activity Score and Tegner Activity Level Scale were unchanged from those before injury. LITERATURE REVIEW: Fracture of the os peroneum is a rare injury and treatment recommendations are based largely on very small series and case reports. Proposed treatment strategies for fracture of the os peroneum include nonoperative treatment, fixation of the fracture, excision of the bone with direct repair of the tendon, and tenodesis of the peroneus longus to the peroneus brevis. PURPOSES AND CLINICAL RELEVANCE: Although some surgeons suggest fracture of the os peroneum should be treated operatively in active patients, this case shows nonoperative treatment allowed pain-free return to activities in a high-level athlete with a minimally-displaced fracture.