Osteochondritis dissecans of the knee

Case contributed by Ammar Haouimi
Diagnosis almost certain


Right knee pain.

Patient Data

Age: 25 years
Gender: Male

Well-defined osteochondral defect of the posteromedial aspect of the medial femoral condyle with underlying bone marrow edema. The detached osteochondral fragment is moderately displaced completely surrounded by the joint effusion.

Another small displaced osteochondral fragment is seen anterior to the distal ACL of low signal on all sequences with surrounding effusion, well-demonstrated mainly on sagittal sequences.

ACL, PCL, and collateral ligaments are intact. No meniscal tear is seen

Well-defined lobulated lesion of the distal femur (37 mm) with a sharply defined peripheral hypointense sclerotic rim suggestive of non-ossifying fibroma.

Case Discussion

MRI features of an osteochondritis dissecans of the knee grade IV with a non-ossifying fibroma (incidental finding in this case).

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.