Does involvement of the anterior syndesmosis affect the functional outcome of acute ligamentous ankle injuries?

Purpose: To compare patient-reported outcomes between acute ligamentous ankle injuries 1) without anterior syndesmosis involvement and 2) with anterior syndesmosis involvement (without clinical instability).

Study design: Prospective cohort study.

Methods: Between September 2016 and December 2020 all athletes (≥18) with an acute ankle injury presenting within 7 days post-injury were screened for eligibility. Athletes were excluded if imaging demonstrated a frank fracture or 3T magnetic resonance imaging could not be acquired within 10 days post-injury. Athletes with unstable syndesmosis injuries or athletes who underwent surgery within 1-year post-injury were excluded. Athletes underwent criteria-based rehabilitation and functional outcomes (Karlsson & Peterson score, Foot and Ankle Outcome Score) were assessed at 6 weeks, 6 months, and 1 year.

Results: A total of 94 athletes were included. In 28 athletes (30 %) the anterior syndesmosis was injured. In the first six weeks post-injury, median Karlsson & Peterson score improved from 37 (interquartile range 20.5-49) to 80 (interquartile range 70-90) for the group without involvement versus 35 (interquartile range 25-62) to 82 (interquartile range 72-87) for the group with involvement. FAOS sports improved similarly in both groups. No statistically significant between group differences in functional outcome scores were observed at six weeks, six months and 1 year follow-up.

Conclusions: In athletes, acute ligamentous ankle injuries with involvement of the anterior syndesmosis ligament (without clinical instability) are not associated with worse functional outcome at 6 weeks, 6 months, and 1-year post-injury compared to acute ligamentous ankle injuries without involvement.