Posterior cruciate Ligament Tear

Proton-dense sagittal image shows the gentle convex sloping course of the normal posterior cruciate ligament. Contrast this with Picture 11, in which the ligament is more vertical. Courtesy of Javier Beltran, MD, Maimonides Medical Center.

The magnetic resonance imaging(MRI) scan is probably the most accurate test without actually looking into the knee. The MRI machine uses magnetic waves rather than X-rays to show the soft tissues of the body. This machine creates pictures that look like slices of the knee. The pictures show the anatomy, and any injuries, very clearly. This test does not require any needles or special dye and is painless.

Combined anterior and posterior cruciate ligament (PCL) tear. Proton-dense sagittal image demonstrates straightening of the orientation of the course of the PCL (straight black arrow in A) resulting from the loss of the normal restraining function of the anterior cruciate ligament secondary to a severe tear (as in Image 5). The proton-dense coronal view shows almost all of the substance of the PCL within one image (C), reflecting the abnormal accentuated vertical orientation of the ligament.