Arthroscopic treatment of anterolateral soft tissue impingement of the ankle: Evaluation of factors affecting outcome

Purpose: To evaluate the results for patients treated arthroscopically for anterolateral soft tissue impingement syndrome, to determine the factors affecting the outcome, and to report on a synovial shelf. Type of study: Retrospective clinical review. Methods: Forty-one patients underwent operative arthroscopy for anterolateral impingement of the ankle between 1990 and 2001; the mean follow-up was 83.7 months (range, 21 to 152 months). There were 25 men and 16 women with an average age of 33.2 years (range, 15 to 63 years). All patients reported a history of inversion injury to the ankle. The most frequent preoperative complaints were tenderness localized to the anterolateral aspect of the ankle, swelling, crepitation, and pain at weight-bearing. All patients had failed to respond to at least 3 months of conservative treatment. The results were assessed according to Meislin's criteria and the American Orthopaedics Foot and Ankle Society (AOFAS) scoring table. For statistical analysis, the Mann-Whitney U test was used where appropriate and the significance was set at P < .005. Results: According to Meislin's criteria, there were excellent results in 21 patients, good in 16, fair in 2, and poor in 2. The mean AOFAS score was 89.6 points (range, 60-100) at follow-up. Four different soft tissue pathologies causing impingement were described. It has been statistically shown that cartilage damage located at the anterolateral region of the ankle and not advanced to the subchondral bone, and repeated inversion injuries had negative effects on clinical results at long-term follow-up. Conclusions: The arthroscopic diagnosis and treatment of anterolateral soft tissue impingement is a safe and effective method. Any combination of associated intra-articular pathologies, such as a chondral lesion or a new inversion injury of the ankle, after the arthroscopic procedure resulted in a poor outcome. Level of evidence: Level IV, Therapeutic Study.