FUNCTIONAL-EVALUATION OF THE 10-YEAR OUTCOME AFTER MODIFIED EVANS REPAIR FOR CHRONIC ANKLE INSTABILITY

The Evans tenodesis is an operative treatment for chronic ankle instab ility with good short-term results.(18,24,25) The disadvantage of impa ired hind foot kinematics and restricted motion has been described,(6, 16) and only few reports of long-term results can be found.(14) No tec hniques have been used to assess the outcome objectively, We wanted to determine whether a modified Evans procedure(33) led to a satisfactor y clinical and functional outcome, Nineteen patients were available at a 10-year follow-up. The clinical examination included a detailed que stionnaire and stress radiographs. Foot function was evaluated with pl antar pressure distribution measurements during walking and peroneal r eaction time measurements elicited on a rapidly tilting platform (reco rded with surface electromyography). High subjective patient satisfact ion was contrasted with a high rate of residual instability, pain, and swelling. The radiographs showed an increased number of exostoses. Th e gait analysis revealed reduced peak pressures under the lateral heel and increased values under the longitudinal arch. The reaction times of the peroneal muscles were shorter on the operated side (significant : peroneus longus), The persistent clinical problems as well as the fu nctional changes indicate that the disturbed ankle joint kinematics pe rmanently alter foot function and may subsequently support the develop ment of arthrosis, Therefore, the Evans procedure should only be appli ed if anatomical reconstruction of the lateral ankle ligaments is not feasible.