Comparison of Outcomes of Arthroscopic Modified Broström Procedure for CLAI in Patients with Solitary ATFL Injury and in Patients with ATFL and CFL Complex Injury

Category: Ankle; Arthroscopy Introduction/Purpose: ATFL (Anterior talofibular ligament) and CFL (Calcaneofibular ligament) are most commonly injured structures when ankle sprained. There has been debate about whether CFL should be recovered by surgery. Recently, several studies have verified that MBP (Modified Broström procedure) with IER (Inferior extensor retinaculum) augmentation demonstrated good outcomes even in patients with ATFL and CFL complex injury. However, some studies presented that IER augmentation cannot cover CFL injuries because of a different vector. If so, we hypothesized that the patients with solitary ATFL injury would show better outcomes comparing with patients with ATFL and CFL complex injury when same arthroscopic MBP was performed for each group. Methods: 208 ankles were included between September 2015 and October 2019. All the patients were underwent arthroscopic MBP with IER augmentation using knotless suture anchor technique. Complete ATFL injuries were determined by arthroscopy and CFL injuries were examined by magnetic resonance image. 26 ankles of which talar tilt angle was less than 9 degrees in ATFL and CFL complex injury group were excluded. Finally, 38 ankles with solitary ATFL injury and 31 ankles with ATFL and CFL complex injury were enrolled. Clinical and radiological outcome were measured and compared between two groups. Clinical outcome was divided into objective and subjective outcome. Objective outcomes were composed of VAS, AOFAS score and FAOS. Subjective outcome was presented as subjective satisfaction score (1: Excellent, 2: Good, 3: Fair, 4: Poor). Improvement of degree of anterior talar translation and talar tilt angle between preoperative and 12 months after surgery was measured as a radiological outcome. Results: P-values of VAS score at preoperative, 3 months, 6 months and 12 months after surgery were 0.3761, 0.2609, 0.3893 and 0.2547 respectively (95% confidence interval[CI]). P-values of AOFAS score at preoperative, 3 months, 6 months and 12 months after surgery were 0.2079, 0.64, 0.6339 and 0.2683 respectively (95% CI). P-values of FAOS and subjective satisfaction score at 12 months after surgery was 0.1379 and 0.6338 respectively (95% CI). P-values of anterior talar translation and talar tilt angle were 0.4371 and 0.0002 respectively (95% CI). The degree of talar tilt angle improvement was -1.91 in solitary ATFL injury group and -5.48 in ATFL and CFL complex injury group. Conclusion: The outcomes of arthroscopic MBP with IER augmentation for chronic lateral ankle instability in patients with Solitary ATFL injury and in patients with ATFL and CFL complex injury showed no differences except talar tilt angle improvement. Though talar tilt angle improvement showed difference between two groups, the degree of improvement was even better in ATFL and CFL complex injury group. It means arthroscopic MBP could be a good treatment options for chronic lateral ankle instability patients regardless of CFL injury.