Non-Anatomic All-Inside Arthroscopic Anterior Talofibular Ligament Repair with a High Position Anchor Shows Inferior Clinical Outcomes: A 3D-CT Based Analysis in Chronic Ankle Instability Patients

CATEGORY: Arthroscopy; Sports INTRODUCTION/PURPOSE: In chronic ankle instability (CAI), it is important to repair the anterior talofibular ligament (ATFL) at the anatomic origin site. However, there are limited reports on the clinical outcomes according to anatomical ATFL repair. The purpose of this study is to compare the clinical outcomes after arthroscopic ATFL repair, according to whether the anchor is fixed at an anatomic position. METHODS: We performed a retrospective review of consecutive patients who underwent arthroscopic ATFL repair for CAI and were available for a minimum of 2 years follow-up. The patients were divided into three groups according to the anchor position at the distal fibula on 3-dimensional computer tomography: group A, anatomical arthroscopic ATFL repair; group S, sub- anatomical arthroscopic ATFL repair; and group N, non-anatomical arthroscopic ATFL repair. The pain (visual analogue scale [VAS]) score, foot and ankle outcome score (FAOS), and the Karlsson ankle functional score were measured as subjective outcomes. Posturographic analysis and radiologic evaluation using stress radiographs and axial view magnetic resonance imaging were performed as objective outcomes. RESULTS: Of 96 patients, 16 were excluded based on the exclusion criteria, and 80 were evaluated (group A, n = 24; group S, n = 42; and group N, n = 14). The mean age of the patients was 34.5 years, and the mean follow-up period was 27.4 months. A between-group comparison revealed significant differences in the FAOS, Karlsson score, and fall risk evaluated by posturography at the final follow-up. Post hoc analysis revealed that group A patients showed better clinical scores in the FAOS than group N patients in all five domains (all p < 0.017). Patients in groups A and S showed better Karlsson score and fall risk than those in group N (p = 0.004 and 0.013, respectively). In terms of objective outcomes, patients in groups A and S showed better outcomes in fall risk than those in group N (both p = 0.001). CONCLUSION: Non-anatomic ATFL repair showed inferior outcomes compared to anatomic ATFL repair. When performing arthroscopic ATFL repair, the anchor should be fixed in the anatomical position to improve prognosis.