[Diagnosis and therapy of acute and chronic ligament instability of the lower ankle joint].

At the Casualty Clinic of the University Hospital in Hannover, from 1981 to 1985, a total of 35 patients were treated operatively for chronic instability of the transverse tarsal joint: combined instability of the ankle and transverse tarsal joints (n = 15), isolated instability of the subtalar joint (n = 17), and isolated instability of the pretalar joint (n = 3). A simple technique of radiological positioning permits easy and certain diagnosis of isolated anterolateral rotary instability of the subtalar joint. Modified Elmslie tendosis (n = 32), used as an indirect replacement for the interosseus talocalcaneal ligament, had good and very good results in 25 of 27 cases followed up after 3 years.