Best Practice Case Studies-Anterior Cruciate Ligament Tear

Video Transcription

Hi, this is Sagar Wagle, one of the musculoskeletal radiology fellows at Stanford University.  We have a case of a 25 year old male presenting two weeks after a volleyball injury, and there is a concern for  ACL tear. This is the MRI image from the patient. Before we go into the MRI, let's look at a normal example of ACL. As we scroll through these images,  the ACL comes into view. It is oriented in this oblique direction, it's taut, and it's low in signal intensity. If we compare the ACL fibers to the PCL fibers back here,  we can see that the PCL is usually more thicker than the ACL.  So this is normal appearance of ACL.  Let's look at a case of an ACL tear. Right when we start the image, we can see that there's a large knee joint diffusion.  We can see that there's a fluid-fluid level indicating that this is a lipohemothrosis. As we scroll through the images,  so this is where we should see a normal ACL. The ACL fibers are really thickened and  it has increased signal intensity. So this is consistent with a high grade tear of the ACL. And here we can see the normal PCL fibers.  So this is a case of normal ACL and this is high grade ACL tear.  Now, let's look at our original case.  We do see a little bit of distal ACL fibers,  but the fibers are truncated, they're sagging, and we do not see anything resembling normal ACL fibers, which should be oriented in this general direction.  We also see a large knee joint diffusion.  So this is a case of a full thickness ACL tear and we can compare that to a normal ACL here. Thank you for watching the video.

Video Summary

In this video, Sagar Wagle, a musculoskeletal radiology fellow at Stanford University, reviews an MRI of a 25-year-old male suspected of an ACL tear following a volleyball injury. He demonstrates the normal appearance of an ACL on MRI, highlighting its oblique orientation, tautness, and low signal intensity. In contrast, a high-grade ACL tear exhibits thickened fibers with increased signal intensity and is often accompanied by knee joint effusion and lipohemothrosis. The patient’s MRI confirms a complete ACL tear, characterized by truncated, sagging fibers and significant joint effusion.

Meta Tag

Edition 3rd Edition

Related Case 3rd Edition, CASE 29

Topic Knee

Keywords

3rd Edition, CASE 29

3rd Edition

Knee

ACL tear

MRI

knee joint effusion

volleyball injury

musculoskeletal radiology