IMPORTANT: We currently have a number of bugs related to image cropping and are actively trying to resolve them. In the meantime, we have disabled cropping. Apologies for any inconvenience. Stay informed: radiopaedia.org/chat

Post-traumatic soft tissue cyst - knee

Case contributed by Maulik S Patel
Diagnosis almost certain

Presentation

Trauma to knee six weeks earlier, presents with anterior knee swelling without much pain

Patient Data

Age: 50 years
Gender: Female

Soft tissue swelling is noted in anterior knee, involving supra-, pre-, infrapatellar regions.

Quadriceps and patellar tendon soft tissue shadow are separately visualized.

No fracture/dislocation.

ultrasound

Site of swelling shows an encapsulated fluid collection with tiny echoes. Single echogenic ovoid focus is noted within the lesion representing a fat globule. Few thin avascular septa are present. Thin wall (up to 1.5 mm) is noted surrounding the lesion.

Adjacent fat is echogenic.

Patellar and quadriceps tendon - intact.

No joint effusion noted in suprapatellar recess.

Case Discussion

Findings favor post traumatic soft tissue cyst involving knee.

If morphologically-similar lesion is present over the greater trochanter of the femur, then it is called a Morel-Lavallée lesion.

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.