Abstract
This study aimed to investigate the relationship between bone morphology and injured
ligaments on imaging studies and laxity on ankle stress radiographs in patients with
lateral ankle instability. In total, 115 patients who had undergone ankle MRI, ankle
radiography, and stress radiography were included. Distal tibial articular surface
angle, bimalleolar tilt, medial and lateral malleolar relative length, medial malleolar
slip angle, anterior inclination of the tibia, and fibular position were measured
on ankle radiographs. Tibiotalar tilt angle and anterior translation of the talus
were measured on ankle stress radiographs. Degree of ligament injury was evaluated
on ankle MRIs. Multiple regression analysis was performed using the following independent
variables: age, sex, and factors significantly associated with ankle stress view on
univariate linear regression analysis. Age (p=0.041), sex (p=0.014), degree of anterior
talofibular ligament injury (p<0.001), and bimalleolar tilt (p=0.016) were correlated
with tibiotalar tilt angle. Fibular position and degree of posterior talofibular ligament
injury were factors significantly related to anterior translation of the talus. Differences
in patient characteristics might predispose ankle stress radiograph results. Comparison
of both ankles on stress radiographs is superior to applying fixed numerical values
to the injured side in order to reduce the influence of patient factors.
Key words
ankle stress radiographs - lateral ankle instability - anterior talofibular ligament
- bimalleolar tilt - tibiotalar tilt angle - fibular position
