Preliminary study using shear wave elastography to evaluate anterior talofibular ligament stiffness in chronic ankle instability.

Introduction: Anterior talofibular ligament injury is the most common type in chronic ankle instability patients. While initial injuries are often treated conservatively, some patients still require surgery. Shear wave elastography provides quantitative, accurate assessment of ligament damage, offering an objective basis for surgical planning and rehabilitation monitoring.

Method: Shear wave elastography quantified shear wave velocity of bilateral anterior talofibular ligaments in neutral and stressed positions in 30 chronic ankle instability patients' group and 60 healthy controls' group. Functional assessments included the Cumberland Ankle Instability Tool, American Orthopaedic Foot & Ankle Society scale, Foot and Ankle Ability Measure for Activities of Daily Living and Foot and Ankle Ability Measure for Sports (FAAM-S) and Visual Analogue Scale for pain.

Results: Inter-observer and test-retest reliability for anterior talofibular ligament shear wave velocity were excellent (neutral position: intraclass correlation coefficient = 0.87, 0.93; stressed position: intraclass correlation coefficient = 0.89, 0.96). Shear wave velocity showed no significant differences by gender, age or body mass index. Chronic ankle instability patients had significantly higher shear wave velocity in affected anterior talofibular ligaments (neutral/stressed, p < 0.001) versus healthy controls; unaffected sides showed no difference. Affected ankles scored significantly worse on Cumberland Ankle Instability Tool, Foot and Ankle Ability Measure for Activities of Daily Living, Ankle Ability Measure for Sports, American Orthopaedic Foot & Ankle Society and Visual Analogue Scale (p < 0.001). Shear wave velocity in affected anterior talofibular ligaments (both positions) positively correlated with pain intensity (neutral: r = 0.488, p = 0.004; stressed: r = 0.514, p = 0.004). Neutral-position shear wave velocity negatively correlated with Foot and Ankle Ability Measure for Activities of Daily Living (r = -0.457, p = 0.011), but not with Ankle Ability Measure for Sports, American Orthopaedic Foot & Ankle Society or Cumberland Ankle Instability Tool scores.

Conclusion: Shear wave elastography noninvasively, conveniently and accurately assesses anterior talofibular ligament quality in chronic ankle instability patients, providing an objective approach for surgical decision-making and rehabilitation monitoring.