Abstract
Os subfibulare, a rare accessory ossicle located at the distal fibula, is hypothesized to result from the failure of fusion of a secondary ossification center or chronic avulsion fractures. While often asymptomatic, symptomatic cases associated with pain and ankle instability may require surgical intervention when conservative management fails. This report describes the case of a 16-year-old female who was successfully treated with cannulated cancellous screw fixation, achieving complete symptom resolution, restoring ankle stability, and significant functional improvement. This case highlights the importance of selecting optimal surgical strategies for large fragments to restore joint stability and improve outcomes. Given the short-term follow-up of this study, further research is necessary to evaluate long-term efficacy and refine treatment protocols.