Arthroscopic capsular shrinkage for chronic ankle instability with thermal radiofrequency: prospective multicenter trial

The study was designed as a prospective multicenter longitudinal trial. Adult patients with symptomatic mechanical chronic ankle instability, not improving with conservative therapy, were included and underwent surgery. Primary outcome measures were radiological and manually tested mechanical laxity. Secondary outcome measures were number of complications, reoperations and symptoms, range of motion, and functional (ankle) scores (Karlsson and SF-36 score). The latest follow-up was 9 months for each patient. Thirty-nine patients underwent surgery (19 male patients; 16 right ankles; median age, 27 years). Mechanical stability showed no clinically relevant improvement whereas most secondary outcome measures showed a substantial and statistically significant improvement. One surgery-related complication occurred without functional consequences, and 3 patients underwent a secondary procedure. One was considered a treatment failure, requiring an open anatomic ligament reconstruction. The second patient sustained a severe supination trauma by starting intensive training too early, also requiring an open anatomic reconstruction. The third patient had posterior ankle pain, which was successfully treated by posterior ankle arthroscopy. Arthroscopic thermal capsular shrinkage of the ankle is a safe procedure, leading to resolution of symptoms in the majority of patients with chronic ankle instability