Presentation
Knee pain without trauma
Patient Data
Sagittal DP fat suppressed weighted MR image, shows mucoid degeneration with enlarged ACL of almost homogeneous intermediate signal intensity.
Sagittal DP fat-suppressed-weighted MR image of posterior cruciate ligament (PCL) shows diffuse thickening and longitudinally increased signal intensity with peripheral rim of hypointense PCL fibers (tram-track PCL appearance) 1.
Horizontal lesion of the posterior horn of the medial meniscus is associated.
Case Discussion
ACL mucoid degeneration is characterized by degeneration of collagen fibers and deposition of new glycosaminoglycans. The MRI features suggestive of ACL mucoid degeneration are abnormally thickened and an ill-defined, bulky ACL, with increased intra-ligamentous signals. On all sequences interspersed among visible intact fibers (celery stalk sign). MRI distinguishes mucoid degeneration from partial or complete lesions of the cruciate ligaments.