Evaluation of the Anterior Talofibular Ligament by Stress Ultrasound for Assessing Generalized Joint Hypermobility

Abstract

Category: Ankle; Basic Sciences/Biologics Introduction/Purpose: Chronic ankle instability with generalized joint hypermobility (GJH) is considered a relative contraindication for the modified Bröstrom procedure. Most clinicians use the Beighton score to assess GJH. However, the Beighton score itself does not involve investigation of the ankle joint. In our experience, resting, longitudinal ultrasound images of the uninjured, intact ATFL frequently show a loose, wavy pattern in patients with high Beighton scores. We evaluated anterior talofibular ligament (ATFL) status according to Beighton score and the manual anterior drawer test (ADT). It was hypothesized that the value of ultrasound for ATFL would be significantly different between participants with GJH (Beighton score >= 5) and without GJH and show a correlation with participant’s Beighton scores and manual ADT grades. Methods: Forty-four healthy young patients (44 ankles) aged 20 to 40 years and without a history of ankle trauma or disease were included in the study. To assess GJH and ankle instability, Beighton scores and manual ADT grades were evaluated, respectively. For the investigation of ATFL, resting and stress ultrasonography were performed to assess its length, height, and thickness. Ultrasound images were taken in resting position and during maximal plantar-flexion and inversion (Figure: Ultrasound images of the ATFL in (a) the resting position and (b) stress position in a 21-year-old woman with Beighton score of 9. Dotted red line: Length, Yellow line: Height, Green double-headed arrow: Thickness). Beighton scores, manual ADT grades, and ultrasound parameters of participants with and without GJH were compared and the correlation coefficients among Beighton scores, manual ADT grades, and the length, height, and thickness of resting and stress ATFLs were analyzed. Results: The participants were divided into two groups, those without GJH (24 ankles) and with GJH (20 ankles). Mean Beighton scores and manual ADT grades were significantly different between the two groups (P < .05). The mean length, height of resting, stress ATFL and mean difference in height between resting and stress ATFL were significantly different between the two groups (P < .05). The resting and stress ATFL length, height, and difference in height between resting and stress ATFL showed a moderately positive linear relationship with Beighton scores and manual ADT grades (P < .05). Among the ATFL parameters, resting ATFL height showed the strongest relationship with the Beighton score (r = 0.763, P < .001) and ADT grade (r = 0.763, P < .001). Conclusion: The ATFL stress ultrasound parameters showed significant differences between participants with high and low Beighton scores and were correlated with Beighton scores and manual ADT grades. We believe that this ankle joint specific method might provide significant, quantitative parameters for assessing GJH in addition to the Beighton score.