Joint-preserving surgery of ankle osteoarthritis.

Introduction: The most common cause of ankle osteoarthritis (OA) is posttraumatic, with around 80% of all cases, followed by primary and secondary ankle OA. Patients often present wit asymmetric involvement of the tibiotalar joint, resulting in valgus or varus deformity of the ankle and hindfoot. The etiology of asymmetric arthritic ankles can be divided into 2 main etiologic and morphologic groups. The primary form of asymmetric ankle OA is characterized by severe deformity of the pes planovalgus, with insufficiency of the medial ligaments and end-stage tibial tendon dysfunction (Grade IV using the Myerson classification) in patients with valgus OA or severe cavovarus deformity in patietns with varus OA. The second important etiologic category of asymmetric ankle OA is posttraumatic. Severe ankle fractures with valgus or varus impacted tibial plafond may end up in posttraumatic ankle OA. Furthermore, patients with malunited fibula fracture with shortened and externally rotated fibula may present with asymmetric valgus ankle OA.