Open Evaluation of the Peroneal Tendons Should Be Considered in Patients With Chronic Lateral Ankle Instability Undergoing Ankle Arthroscopy With Lateral Ankle Stabilization.

Abstract Peroneal tendon pathology is commonly associated with chronic lateral ankle instability. Foot and ankle surgeons often rely on preoperative MRI for identification of related pathology and surgical planning in these patients. The purpose of this study was to assess the ability of preoperative MRI to accurately detect peroneal tendon pathology in patients with chronic lateral ankle instability. Consecutive surgical cases involving arthroscopic evaluation and management of lateral ankle instability sequelae were evaluated retrospectively. Preoperative MRI images were compared to intraoperative findings in order to determine the sensitivity, specificity, positive and negative predictive values. Eighty-two patients met inclusion criteria, 58 females and 24 males. The average age at the time of surgery was 46 years (range 13-75). Peroneal tendon pathology was identified intra-operatively in 76 (92.7%) patients and on MRI in 40 (48.8%) patients. The most commonly identified pathologies were tenosynovitis, tendinopathy and longitudinal split/tear, with the peroneus brevis tendon being most commonly involved. MRI was 38.7% specific, 50.0% sensitive, had a positive predictive value (PPV) of 92.5%, and a negative predictive value (NPV) of 7.1%. While MRI is a helpful study for evaluation of co-pathologies and surgical planning in patients with lateral ankle instability, procedural selection should not be solely based on MRI results, and the peroneal tendons should be evaluated intra-operatively in patients undergoing arthroscopic procedures for lateral ankle instability.