Retrofibular osteochondroma with peroneal tendon subluxation

• We report a distal retrofibular osteochondroma causing peroneal tendon subluxation.
• We discuss the diagnosis, treatment and post-operative outcomes.
• Osteochondromas cause diverse complications involving close anatomical structures.
• Surgery involved excision, groove deepening and Brostrom–Gould reconstruction.
• Symptoms of instability and subluxation completely resolved post-operatively.

Osteochondroma of the bone can cause a range of complications involving tendons, joints and neurovascular structures. Distal fibular osteochondroma and non-traumatic peroneal tendon subluxation are both rare. In this case report, we describe an unusual case of distal retrofibular osteochondroma in a 36-year old male causing peroneal tendon subluxation. He presented with pain and instability around his ankle, but with no history of trauma. He successfully underwent osteochondroma excision, peroneal groove deepening and a Brostrom–Gould type reconstruction for the lateral ankle ligament insufficiency. Complete resolution of the symptoms of instability and subluxation was noted upon 6-month follow up.