Suture-Button Repair Improves Outcomes in Arthroscopically Diagnosed Chronic Syndesmotic Injury Despite Low Imaging Sensitivity.

Purpose: To evaluate patient-reported outcomes after arthroscopic suture-button repair of chronic isolated syndesmotic injuries and to compare the diagnostic sensitivity of standard imaging with arthroscopy. Methods: Patients with chronic (≥3 months) syndesmotic injuries confirmed by arthroscopy (≥2 mm widening) who underwent suture-button repair between 2017 and 2021 were included. Exclusion criteria were ankle fractures, previous major surgery, or significant arthritis. Foot Function Index and Foot-and-Ankle Ability Measure scores were recorded preoperatively as part of routine clinical assessment and at final follow-up. The minimal clinically important difference was defined as 75% of preoperative standard deviation. Results: Forty-one patients (43 ankles) were analyzed. Median age was 32 years (15-57 years), 63% were female, and time from injury to surgery was 1.7 years (0.25-25). Fifteen ankles (35%) received concomitant lateral suture-tape stabilization. Arthroscopic syndesmotic widening was 2-3 mm in 5%, 3-4 mm in 10%, >4 mm in 46%, and posterior in 38%. All 6 Foot Function Index and Foot-and-Ankle Ability Measure subscores improved significantly ( Conclusions: Arthroscopic suture-button repair led to significant improvements in patient-reported outcomes for chronic isolated syndesmotic injuries. Standard imaging had low sensitivity, and a posterior-predominant syndesmotic widening pattern was commonly observed arthroscopically. These findings suggest that chronic syndesmotic instability is underdiagnosed, highlight the role of arthroscopic evaluation for accurate diagnosis, and support the use of suture-button stabilization as an effective treatment. Level of Evidence: Level IV, therapeutic case series.