Lateral ligament injury of the ankle and associated articular cartilage degeneration in the talocrural joint: anatomic study using elderly cadavers

We investigated degenerative changes (DCs) of the articular cartilage using 33 cadaveric talocrural joints with anterior talofibular ligament injuries. The control group (93 normal ankles) were age- and sex-matched with the injury group. The injured ligament carried unusual wavy collagen bundles with hyalinization (or elongation) or rupture with scar. In both groups, we found talar-side dominance of DCs, multifocus occurrence, and a high incidence of mirror-image DCs in the medial parts of the joint. However, the mirrorimage lesion was multiple or large (or both) in the injury group in contrast to its restricted nature in the control. Thus, the averaged numbers of affected areas or sectors in the injury group were almost twice as large as in the controls. A significantly high incidence of DCs, especially of the mirrorimage lesion, was found in the lateral malleolar facet in the injury group. Although initial DC lesions might be at a medial site in the joint, as hypothesized in the control group, the lateral ligament injury seemed to increase the dominance of DCs on the lateral site. Consequently, early evaluation and treatment for lateral ligament insufficiency is more necessary in elderly patients than in younger patients to avoid widespread development of osteoarthritis.