Case contributed by Henry Knipe


Fall at the races. Tender patella.

Patient Data

Age: 55 years
Gender: Male

No fracture or malalignment. No definite knee joint effusion. Pre-patella soft tissue swelling consistent with bruising/hematoma given recent history of trauma. Incidental note of a fabella.      

Annotated image

Red circle highlights the fabella. 

Case Discussion

A fabella is a common accessory ossicle found in the lateral tendon of the gastrocnemius. It should not be confused for a fracture or an ossified intra-articular body.

Pre-patella soft tissue swelling is well seen on lateral knee radiographs and important to comment on as it is often clinically confused for a joint effusion. 

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.