An unusual presentation of Trevor’s disease at the ankle joint: Involvement of both medial and lateral epiphyses

•Trevor’s disease (hemimelica) typically affects one side of an epiphysis (usually the medial side).•However in this case both medial and lateral sides of the talus were involved.•Other joints should be examined in terms of multiple involvements.•Surgery on lesions causing impingements may improve functional status and relieve pain. Trevor’s disease, also known as dyplasia epiphysealis hemimelica, is characterised by osteochondromas arising from epiphyses. The disease typically affects one side of an epiphysis (usually the medial side). A case in whom both the medial and lateral sides of the epiphysis were involved is described. Thus, the use of the descriptor “hemimelica” is not always appropriate. Although rare, Trevor’s disease should be kept in mind during the differential diagnosis of patients with ankle pain and a mass. Other possible joints should be examined to explore multiple involvement. Surgical treatment, only on lesions causing impingements, may improve functional status and reduce pain.