Outcomes of Osteosynthesis of Large Os Subfibulare in Patients with Chronic Lateral Ankle Instability with Large Os Subfibulare

Category: Ankle; Sports Introduction/Purpose: Os subfibulare is commonly found in patients with chronic lateral ankle instability (CLAI). When performing lateral ligament reconstruction for CLAI, excision of a large OS can cause massive lateral ligament defects.The purpose of this study is to evaluate clinical and radiological outcomes among patients who underwent osteosynthesis of the OS for chronic lateral ankle instability with a large OS (≥10 mm). Methods: A retrospective analysis was performed on 28 ankles with CLAI and a large OS (≥10 mm) that underwent osteosynthesis of the OS between June 2007 and July 2021 and had a minimum follow-up of 2 years. Visual Analog Scale for pain, Karlsson–Peterson ankle score, and Medical Outcomes Study Short Form Health Survey-36 Physical Component Summary (SF-36 PCS), talar tilt angle, and anterior displacement of the talus were used to assess clinical and radiological outcomes. Results: The mean follow-up period was 78.9 months (range, 24.0 to 177.0 months) and the mean OS size was 15.4 mm (range, 12.2 to 21.0 mm). Mean ± SD Visual Analogue Scale for pain, Karlsson–Peterson ankle score, SF-36 PCS, talar tilt angle, and anterior displacement of the talus improved significantly, from preoperative values of 5.3 ± 1.8, 38.4 ± 10.6, 45.6 ± 10.8, 11.1 ± 5.7, and 7.3 ± 1.9, to 0.9 ± 1.4, 88.7 ± 12.6, 80.2 ± 12.3, 3.9 ± 2.0, and 4.8 ± 1.3, respectively, by the last follow-up. The overall complication rate was 10.7% (three ankles); the reoperation rate was 7.1% (two ankles). Conclusion: Osteosynthesis of the OS produced satisfactory outcomes in patients with CLAI with a large OS. This method may be a viable surgical option for patients with this condition.