The Prevalence and Clinical Significance of FHL Tears in Athletes with Posterior Ankle Impingement Surgery

Abstract

Category:Ankle, Hindfoot, SportsIntroduction/Purpose:Posterior ankle pain in the athlete is common and thought to be caused by Flexor Hallucis Longus (FHL) tendon tear/tendinopathy or Os trigonum syndrome. The association of flexor hallucis longus (FHL) pathology in conjunction with PAIS has not been described. The purpose of this study is to report the prevalence of FHL tears in athletes who undergo surgical treatment for PAIS. We also report the outcome of 36 athletes treated with FHL repair with PAIS surgery and compare them to 122 athletes undergoing PAIS surgery without FHL tears. The utility of advanced imaging, standardized outcome scores at standard post-operative time intervals, return to sport (RTS) and time to RTS were all evaluated in the 158 athletes.Methods:Our clinical database was searched for appropriate surgical codes, and patients from 1996 through March 2016 were retrospectively collected. Inclusion criteria included surgical treatment of PAIS, age between ten and 50, and participation in recreational or competitive athletics. Exclusion criteria included other injuries that could affect return to sport or recovery process. 158 patients met these criteria, (36 dancers, 122 non-dancers). Pre-operative imaging, operative records, dorsiflexion range of motion at six weeks and one year postoperatively, and time to return to sport are reported. AAOS Foot & Ankle, and Lower Limb Core Module (FALLC) scores were obtained (six weeks, three months, and one year post-operatively). Questionnaire data and functionality scores were compared between the two groups using two-sample Student t-tests. Categorical data outcomes were compared using chi-square tests or Fisher’s exact tests.Results:74/158 patients had magnetic resonance imaging (MRI) pre-operatively. 5/14 patients with an FHL tear had positive MRI suggesting an FHL tear, 9/14 patients with FHL tear had negative MRI (sensitivity of 0.26). FHL tears occurred in 36/158 (23%) of athletes with PAIS, 16/36 (44.4%) of dancers and 20/122 (16.4%) non-dancers. RTS did not differ between athletes with and without FHL tears, but time until RTS increased-average of 13.5 days (67.5 versus 81) with FHL repairs. Dancers with FHL tears reported increased foot pain and lower foot and ankle function at 3 months relative to those without tears. Scores were similar at one year.Conclusion:FHL tears in athletes undergoing surgical treatment for PAIS is 23% and in dancers can be as high as 44%. Pre- operative MRI has a poor sensitivity for FHL tears in this population. Concomitant FHL tear with repair during PAIS surgery does not decrease the rate of RTS or long term overall outcome. Overall, dancers have a higher rate of FHL tear at time of PAIS than non-dancers. FHL results in only a mild delay in RTS time. This is the first study to note FHL tear rate in association with PAI surgery.