Absence of ATFL remnant does not affect the clinical outcomes of the modified brostrom operation for chronic ankle instability

Purpose The modified Brostrom operation for chronic ankle instability has demonstrated good clinical results. Absence of ligamentous tissue is a risk factor for recurrence of ankle instability after surgery. This study evaluated the effect of quality of ligament tissue (anterior talofibular ligament, ATFL) on prognosis, in a cohort of patients with chronic ankle instability after the modified Brostrom operation. Methods This was a retrospective case series. Overall, 60 patients underwent the modified Brostrom operation for chronic ankle instability (mean follow-up, 30.1 [range, 24-47] months). Presence of ATFL remnant was assessed on ultrasound, magnetic resonance imaging, and arthroscopy in all patients. Foot and ankle outcome score (FAOS) was used to evaluate functional outcomes. Clinical outcomes were compared by the condition of the ligament remnant. Association with other risk factors was evaluated using multiple linear regression analysis. Results ATFL was visible in 51/60 cases on ultrasound. Thirty, 22, and eight patients had thin or absent; normal thickness; and thick ATFL on magnetic resonance imaging, respectively. ATFL was visible in 15 patients on arthroscopy and nonvisible or not clear in 45. No significant differences occurred in FAOS with the presence of ATFL remnant on ultrasound, arthroscopy, and the grade of ATFL thickness on magnetic resonance imaging. No correlation was found between FAOS and the thickness of ATFL. Conclusion The results suggest that the modified Brostrom operation for patients with chronic ankle instability was good, regardless of the presence or absence of ATFL remnant.