Morphology of the Calcaneofibular Ligament Reflects Degeneration of the Talonavicular Articular Surface: A Cadaver Study

Background: Osteoarthritis is caused by damage to the articular cartilage due to bone-on-bone collisions and friction. The length, width, and thickness of the ligaments are expected to change in order to regulate excessive bone-to-bone movement. We aimed to clarify the relationship between ligament morphology and joint surface degeneration in the ankle joints using macroscopic observations and measurements. Methods: The participants were 50 feet of 45 Japanese cadavers. The lengths, widths, and thicknesses of the tibionavicular, tibiospring, tibiocalcaneal, posterior tibiotalar, anterior tibiotalar, and calcaneofibular ligaments (CFLs) were measured. The degeneration of the talonavicular joint surface was investigated macroscopically and classified into two groups: the Degeneration (+) group and Degeneration (-) group. Unpaired t-tests were performed for each measurement. Logistic regression analysis was performed on the significantly different items to obtain cutoff values, sensitivity, and specificity. Results: Only the width of the CFL differed significantly between the Degeneration (+) (20 feet) and Degeneration (-) groups (p < 0.001). In the logistic regression analysis, the width of the CFL had an R2 of 0.262, sensitivity of 75.0%, and specificity of 83.3%, with a cutoff value of 8.7 mm. Conclusions: A wide CFL indicates a high likelihood of talonavicular articular surface degeneration.