Operative Treatment for Ganglion Cyst of Flexor Hallucis Longus Sheath

Background: Intractable hallucal ganglion cysts (HGCs) are often a symptomatic and recurrent condition. Its connection with the ankle joint is not well understood. Our aim was to evaluate the relationship between tenosynovitis of the flexor hallucis longus (FHL) tendon at the level of the ankle with formation of an HGC. In addition, we sought to analyze the outcomes of cyst excision combined with ankle capsulorrhaphy. Methods: Nineteen patients with HGC who underwent surgical intervention were included between June 2016 and June 2019. Eight had known recurrences. Ankle arthrography and cyst excision were performed on all patients. Clinical evaluations included the American Orthopaedic Foot & Ankle Society (AOFAS) scores, visual analog scale (VAS), and evaluation of postoperative complications. The mean follow-up period was 16.5 ± 8.6 months. Results: Thirteen of the 19 HGCs (68.4%) had a connection with the FHL tendon sheath. Combined with ankle capsulorrhaphy, there was no recurrence after cyst excision. The VAS score decreased from 2.1 ± 1.5 to 0.4 ± 0.8, and AOFAS score significantly improved from 84.3 ± 8.7 to 97.4 ± 5.2 at final follow-up ( P < .001). Conclusions: Most of these patients had a connection between the HGC and ankle joint. Ankle arthrography appeared to be useful for diagnosis, and cyst excision combined with ankle capsulorrhaphy was an effective treatment without cyst recurrence. Level of Evidence: Level IV, case series.