All-inside Arthroscopic Modified Broström Operation for Lateral Ankle Instability with Os Subfibulare

Abstract

Category: Sports Introduction/Purpose: Os Subfibulare(OSF) is an accessory ossicle that lies at the tip of the lateral malleolus of the ankle. Patients with chronic lateral ankle instability (CLAI) have a high incidence of OSF, and there relationship implies that there is a correlation between OSF and CLAI. The all-inside arthroscopic Modified Broström Operation (MBO) has been developed for the treatment of chronic lateral ankle instability (CLAI) and the outcome was reported as good or excellent. But there were no report about comparison of the outcome between OSF and non-OSF patients with chronic lateral ankle instability treated by all-inside arthroscopic MBO. The purpose of this study was to evaluate the clinical and radiologic outcomes of the arthroscopic MBO procedure for CLAI with or without OSF. Methods: From January 2013 to september 2016, arthroscopic MBO was performed on 133 patients with CLAI. Of these, 126 ankles were evaluated for this study. Patients were divided into two groups: the OSF group (26 patients), without OSF group (100 patients). Evaluation tools included the American Orthopedic Foot and Ankle Society (AOFAS) hindfoot ankle score and pain Visual Analogue Scale (VAS) at preoperatively, 6 and 12 months postoperatively for clinical outcomes. And we also evaluated the talar tilt angle in the varus stress radiograph at preoperatively, 6 and 12 months postoperatively for radiologic outcomes. Results: There were no difference in age, sex, preoperative AOFAS hindfoot ankle scores and VAS scores and talar tilt angle between the two groups preoperatively(P >.05). And there also were no difference at the final follow-up (P >.05).The final follow-up AOFAS hindfoot ankle score and Vas in both group showed improvement compared with preoperaive values. Conclusion: There were no difference in both clinical and radiologic outcomes between OSF group and non-OSF group at a minimum 12 months follow-up. We achieved similar successful outcomes in both groups using All-inside arthroscopic MBO. Arthroscopic MBO should be considered as a reasonable alternative method in patients who have chronic lateral ankle instability regardless of the presence of OSF.