Figure 25.

Anterior cruciate ligament tears are associated with osteoarthritis longitudinally but may also be part of the disease process without a history of trauma. A. Coronal intermediate-weighted MRI shows absence of the ACL. Only intraarticular, extrasynovial fat and no ligamentous fibers are seen at the typical location of the ACL (arrows). B. Another example shows a partial tear of the posterior cruciate ligament (PCL) with hyperintense signal changes and thinning of the ligament (large arrow). In addition there is a large multi-lobulated ganglion cyst adjacent to the PCL (small arrows) that may be a source of symptoms. Further, note diffuse fissuring of the cartilage of the anterior lateral femur. C. Baseline coronal image shows a normal course, signal intensity and thickness of the ACL (arrows). D. Corresponding follow-up image 24 months later shows marked thickening and diffuse hyperintensity of the ligament representing mucoid degeneration, a finding not covered by either scoring system that may potentially be of clinical relevance⁴⁰. In addition, note diffuse cartilage loss at the medial central femur and tibia, which has progressed at follow-up with an incident subchondral femoral cyst.