Preoperative predictors of arthroscopically confirmed lateral ankle micro-instability and two-year outcomes after arthroscopic repair of the ATFL superior fascicle.

BACKGROUND

Lateral ankle microinstability (LAM) caused by anterior talofibular ligament (ATFL) superior fascicle injury is difficult to diagnose preoperatively.

METHODS

Sixty-seven patients with suspected LAM underwent arthroscopy. Preoperative anterior talar translation (ATT), active joint position sense (AJPS), American Orthopaedic Foot & Ankle Society (AOFAS) score, and Karlsson Ankle Functional Score (KAFS) were compared between LAM and non-LAM groups. Logistic regression and Receiver operating characteristic analysis identified predictors. Confirmed LAM cases underwent arthroscopic superior fascicle repair and were followed for 2 years.

RESULTS

Forty-five patients had confirmed LAM. ATT and AJPS errors were significantly greater in the LAM group. ATT and AJPS error at 10° plantar flexion were independent predictors. The combined model showed excellent discrimination (AUC, 0.90). At 2 years, ATT, AJPS, AOFAS, and KAFS improved significantly after arthroscopic repair procedure.

CONCLUSIONS

Combined assessment of ATT and AJPS improves preoperative prediction of LAM. Arthroscopic ATFL superior fascicle repair was associated with improved stability, proprioception, and function.

LEVEL OF EVIDENCE: Level III.