Endoscopic Excision of Os Trigonum in Symptomatic Ballet Dancers of Odisha- A Prospective Cohort Study

Abstract

BACKGROUND The purpose of this study was to evaluate the results of endoscopic excision of symptomatic os trigonum in symptomatic ballet dancers of Odisha. The hypothesis was that posterior endoscopic excision of the os trigonum would be safe and effective in treating PAIS related to the os trigonum. METHODS Between May 2015 and May 2018, 30 ankles of 20 consecutive patients underwent arthroscopic removal of the symptomatic os trigonum for posterior ankle impingement syndrome (PAIS) in prone position. 12 patients were male, 8 female. All patients were ballet dancers by profession where they do the dance in acute flexion of ankle. All patients were discharged on the same day and allowed full weight bearing after 2 weeks post operatively. Mean duration of postoperative follow up was 24 months and no patient was lost to follow up. Clinical evaluations were performed preoperatively & post operatively using the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hind foot score and the Visual Analogue Scale (VAS) for pain. The surgical time, time to return to profession (dancing), patient satisfaction and any complications related to the surgery were assessed. RESULTS Average AOFAS ankle hindfoot score increased from 72.6 ± 5.1 (range 64-78) preoperative to 93.8 ± 3.2 (range 86-100) post-operative (p <0.05) and VAS for pain decreased from 6.8 ± 1.4 (range 5-10) preoperatively to 1.8 ± 0.8 (range 0-4) (p <0.05) at final evaluation. Average plantar flexion of the ankle increased from 27 ± 3.2 (range 20-35) degree to 43 ± 0.4 (range 40-45) degree (p <0.05) post operatively. Mean time to resumption of activity and dancing was 6 weeks (range 4-8 weeks). On physical examination, no patients showed any signs of local tenderness, & the forced planter flexion test findings were negative except in one case in which swelling persisted. There were no major intraoperative & postoperative complications in any patients. Overall patient satisfaction was high. CONCLUSIONS Endoscopic excision of a symptomatic os trigonum in those patients after failure of conservative treatment for ≥6 months using posterolateral and posteromedial portals in prone position was a safe and effective technique with least complications.