Abstract
Os subfibulare is an accessory ossicle of the lateral malleolus at the distal end of the fibula. In most instances, os subfibulare is found incidentally on radiographs. While os subfibulare typically remains asymptomatic, some cases may present with ankle pain or instability. To initiate appropriate treatment and maximize patient outcomes, it is crucial to accurately visualize the accessory ossicle. Here, we report a symptomatic case of os subfibulare diagnosed with ankle radiographs and a 3D water selective cartilage scan (3D_WATSc, Ingenia, Philips Healthcare, The Netherlands) magnetic resonance imaging sequence and treated surgically with open ossicle excision and a modified Broström procedure.