Comparison of the Modified Brostrom Procedure for Chronic Lateral Ankle Instability With and Without Subfibular Ossicle

Background: Subfibular ossicles are frequently found in patients with chronic lateral ankle instability (CLAI). However, there is a lack of consensus about the optimal surgical treatment for CLAI with subfibular ossicle. Purpose: To evaluate the clinical and radiographic outcomes of the modified Brostrom procedure with subfibular ossicle excision compared with the same procedure for CLAI without subfibular ossicle. Study Design: Cohort study; Level of evidence, 3. Methods: Ninety-six patients (96 ankles) treated with the modified Brostrom procedure using bone tunnel and suture anchor techniques for CLAI constituted the study cohort. The 96 ankles were divided into 2 groups with and without subfibular ossicles. The ossicle group (42 ankles) and nonossicle group (54 ankles) consisted of patients with a mean age of 26.6 and 30.3 years, respectively, at the time of surgery with a mean follow-up duration of 63.7 and 62.1 months, respectively. Subfibular ossicles were excised in the ossicle group. Results: Mean Karlsson scores improved from 55.2 to 95.3 in the ossicle group and from 56.4 to 94.8 in the nonossicle group at final follow-up. Mean American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores also improved from 63.3 to 95.9 in the ossicle group and from 62.8 to 95.1 in the nonossicle group at final follow-up. Mean talar tilt angles were 14.0 degrees in the ossicle group and 12.2 degrees in the nonossicle group preoperatively and 7.6 degrees and 6.8 degrees at the final follow-up, respectively. Mean anterior talar translations in the ossicle group and nonossicle groups improved from 9.3 and 9.4 mm preoperatively to 5.8 and 5.7 mm at final follow-up, respectively. No significant differences were found between the 2 groups in terms of Karlsson score, AOFAS score, talar tilt angle, and anterior talar translation at final follow-up (P > .05). Conclusion: The modified Brostrom procedure with subfibular ossicle excision provided similarly good clinical and radiographic outcomes compared with the same procedure without subfibular ossicle excision. Accordingly, the study results suggest that these procedures appear to be effective and reliable method for the treatment of CLAI with subfibular ossicle.