Peroneus Brevis Tendon Variant Insertion on the Calcaneus

Insertion of the peroneus brevis tendon normally occurs at the lateral aspect of the fifth metatarsal base. However, there is new evidence that congenital variant insertion of the tendon on the calcaneal peroneal tubercle occurs in a small segment of the population. We report a case of 24-year old male presenting with non-traumatic ankle pain who underwent ankle magnetic resonance imaging. Imaging demonstrated insertion of the peroneus brevis tendon on the calcaneal peroneal tubercle with absence of the tendon distal to the calcaneus. Furthermore, in reviewing 200 consecutive ankle magnetic resonance examinations, the authors discovered one additional case of this variant. We discuss the magnetic resonance imaging characteristics of this anatomic variant, the implications for clinical management, and review the literature on peroneal anatomic variations.