Arthroscopic Treatment of Tenosynovitis of the Flexor Hallucis Longus Tendon

Background: Tenosynovitis of the flexor hallucis longus (FHL) tendon is a condition typically found in ballet dancers and sometimes in soccer players and is related to chronic overuse. A traumatic cause for this situation, such as an ankle sprain, is considered rare. In case of failure of conservative treatment, the tendon can be surgically released, which is usually done through an open procedure. This article presents the results of an arthroscopic release of the FHL. Methods: Twenty-seven patients underwent surgery for FHL tenosynovitis over a period of 18 months. The mean age of the patients was 34 years. All patients related the onset of the condition with an ankle sprain. Eighteen patients were on worker's compensation and five had sport-related accidents. None of the patients was a professional athlete or a ballet dancer. The mean follow-up was 32 months. The outcome was measured with a satisfaction questionnaire and with the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scoring system. Results: The mean postoperative AOFAS score was 89 with 70% excellent or good results. Mean satisfaction rate was 4 (range, 0 to 5); 89% of the patients would undergo the procedure again. Twenty-two patients (81%) returned to the same level of activity in work and sports. A complication rate of 18% (five patients) and reoperation rate of 4% (one patient) were found. Conclusion: Arthroscopic release of the FHL tendon was a valid procedure. It was a minimally invasive surgery that allowed good visualization of the involved structures and yielded good results. This condition can be related to trauma and is not an exclusive disease of ballet dancers or overuse.