Idiopathic cavovarus and lateral ankle instability: recognition and treatment implications relating to ankle arthritis.

Hindfoot malalignment and chronic lateral ankle instability may lead to degenerative ankle arthritis. We retrospectively analyzed 10 patients with 13 cavovarus feet. None of the patients had underlying neurologic disorders. All patients presented with a history consistent with chronic lateral ankle instability, clinically with cavovarus feet, and radiographically with varying degrees of varus talar tilt and ankle arthritis. Ankles with severe degenerative change were fused. The ankles with mild or moderate change underwent calcaneal osteotomy with lateral ligament reconstruction and/or dorsiflexion osteotomy of the first metatarsal. A quantitative radiographic Coleman block test was utilized to aid in the preoperative planning of the calcaneal and metatarsal osteotomies. All patients had correction of preoperative deformity and resolution of pain and instability. Recognition of the association between cavovarus and chronic ankle instability and degenerative ankle arthritis may be important in developing the appropriate treatment strategy in this patient population.