Treatment of acquired adult planovalgus deformities with subtalar fusion.
A retrospective review was conducted of isolated subtalar arthrodeses performed on 32 adults (34 fusions) between August 1990 and September 1993. Each fusion was performed using a single large cannulated lag screw through the talar neck. The American Orthopaedic Foot and Ankle Society standard clinical rating system for the ankle and hindfoot was used to assess outcome. Patients answered subjective questions based on the scale. Followup examination was done to evaluate clinically and radiographically each patient's foot and ankle according to the scale. Average patient age was 53 years (range, 27-80 years). Average followup was 30.8 months (range, 16-55 months). Twenty-four patients answered the subjective questions, and the average subjective score was 47 of a maximum 60 points (range, 9-60 points). Clinical data from 17 patients showed an average objective score of 30 of a maximum 34 points (range, 25-34 points). The average total score was 77 of a maximum 94 possible points (range, 34-94 points). Forty-two percent of the patients indicated a 100% improvement, 42% a 75% improvement, and 16% a 50% improvement. Eighty-three percent stated they definitely would have the procedure again. Results indicate that subtalar arthrodesis is an effective treatment for adult patients with pain and disability secondary to acquired planovalgus, posttraumatic, and inflammatory conditions of the hindfoot. In addition, the American Orthopaedic Foot and Ankle Society standard rating system of the ankle and hindfoot corresponds to clinical outcome.