Presentation
History of knee pain
Patient Data
MRI shows diffuse thickening of the posterior cruciate ligament (PCL). The sagittal PDW-SPAIR weighted images show the presence of a longitudinally increased signal intensity with a peripheral rim of hypointense PCL fibres; the tram-track sign coexists.
Other findings: There is a mild amount of free fluid in the iliotibial recess. Oblique tears of the posterior horns of both menisci. Advanced chondropathy, likely resultant synovial thickening, cystic degenerative changes.
Case Discussion
Mucoid degeneration of the posterior cruciate ligament (PCL) has been less studied than its counterpart in the anterior cruciate ligament (ACL).
As visualised in the ACL, the increase in signal intensity extending longitudinally throughout a thickened PCL with an intact peripheral rim is analogous to the classic 'celery stalk' morphology of ACL mucoid degeneration.
Given the stability of the PCL on physical examination and the integrity of the peripheral rim of the PCL on MRI examination, the marked thickening (greater than 7 mm) of the PCL can be attributed to mucoid degeneration the MRI appearance of the PCL.