Arthroscopic decompression of the flexor hallucis longus tendon in posttraumatic tendinopathy

Abstract

Background: Tenosynovitis of the flexor hallucis longus (FHL) tendon is more frequent than previously reported, and the condition is often overlooked or misdiagnosed. Overuse in ballet dancers or competitive runners was believed to be the main triggering factor. Recent advances in diagnostic modalities have shown a wide occurrence in nonathletes. The purpose of this study was to evaluate arthroscopic decompression of the FHL tendon in posttraumatic tenosynovitis. Methods: Nine consecutive patients with posttraumatic flexor hallucis longus stenosing tenosynovitis were treated and enrolled in this prospective study. All patients dated their complaint to previous ankle fracture or major sprain. The standard procedure included posterior ankle arthroscopy, thorough debridement of posterior adhesions, and adequate decompression of the tendon at the fibroosseous tunnel. Patients were evaluated for functional outcome through both Foot and Ankle Outcome Score (FAOS) and Ankle-Hindfoot Scale. Results: The mean FAOS score at 1-year follow-up improved from a preoperative mean of 72.56 (SD 4.43) to a postoperative mean of 87.33 (SD 4.03), which is considered to be extremely statistically significant with a P value less than 0.0001. The mean Ankle-Hindfoot Scale improved from a preoperative mean of 71.78 (SD 3.77) to a postoperative mean of 85.33 (SD 5.94). All patients reported being fully satisfied with an overall satisfaction score of 9.42. Conclusions: Flexor hallucis longus stenosing tenosynovitis is more frequent than previously thought and should be considered in patients with posterior ankle pain especially if a history of ankle trauma exists.