Effect of Preoperative Stress Radiographic Findings on Radiographic and Clinical Outcomes of the Modified Broström Procedure for Chronic Ankle Instability

The purpose of the present study is to evaluate whether findings of instability on preoperative stress radiographs of patients with chronic ankle instability affects the radiographic and clinical outcomes after a modified Broström procedure. A total of 45 consecutive patients (45 ankles) who had undergone the modified Broström procedure for unilateral ankle joint instability and were followed up for ≥2 years were selected. The patients were classified into 2 groups according to the results of the preoperative stress radiographs: 1 group with positive findings (35 [77.8%] patients; stress-positive group) and 1 group with negative findings (10 [22.2%] patients; stress-negative group). The radiographic and clinical outcomes were compared between the 2 groups. The mean preoperative talar tilt measured on the stress radiograph was 14.4° ± 4.2° and 4.8° ± 2.6° in the stress-positive and stress-negative groups, respectively, a statistically significant difference. Postoperative talar tilt improved in both groups, with a mean final talar tilt of 5.4° ± 3.4° in the stress-positive group (p < .001) and 3.0° ± 1.5° in the stress-negative group (p = .038). The average American Orthopaedic Foot and Ankle Society ankle-hindfoot score in the stress-positive and stress-negative groups improved from 65.1 ± 14.6 to 90.0 ± 6.3 (p < .001) and 72.5 ± 9.3 to 92.6 ± 7.8 (p = .007), respectively. The mean postoperative satisfaction rate was 83.9 ± 11.9 and 85.0 ± 11.8 in the 2 groups. No statistically significant differences were seen in the preoperative and postoperative American Orthopaedic Foot and Ankle Society ankle-hindfoot scores or in postoperative satisfaction rates between the 2 groups.