An Unusual Case Report of a Stage IV Osteochondral Defect Imitating a Medial Malleolar Avulsion Fracture.

Osteochondral lesions of the talar dome are severely debilitating injuries that frequently can be missed on initial radiographic evaluation. In this case, we present the case of a 17-year-old male who injured his right ankle while skateboarding. Initial radiographic findings showed what appeared to be an avulsion fracture of the medial malleolus, and the patient was subsequently treated with immobilization. It was not until more advanced imaging of computed tomography was performed that the patient was appropriately diagnosed with a displaced talar dome fragment that was positioned in the medial gutter, requiring surgical intervention. This case report serves to show the importance of a proper workup, including advanced imaging, when clinical suspicion of a talar dome lesion is suspected. To the best of our knowledge, this is the only case in literature where a talar defect presents in the medial gutter of the ankle, imitating an avulsion of the medial malleolus.