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

Tuberculosis - knee

Case contributed by Tamsir Rongpipi
Diagnosis certain

Presentation

History of a fall 4 years agho. Now complains for a painless swelling of the knee and pain while walking for the past 2-3 years.

Patient Data

Age: 40 years
Gender: Female
mri

Multiple lobulated synovial effusion and hypertrophy seen involving the left knee joint. There are foci of intermediate to low signal intensity on both T1 and T2 weighted images within the collections --  hemosiderin deposition. Peripheral enhancement of the collections.

Large Baker's cyst in the posterior compartment of the knee joint.

Patchy areas of T2 and STIR hyperintensities in the involved tibia, fibula and femur.  

ct

Erosion with nodular soft tissue masses involving the tibia, fibula, distal femur and patella.

Case Discussion

Tuberculous arthritis is mono-articular arthritis and spares no joints. Large joints like the hip and knee are the most commonly involved joints.

Musculoskeletal involvement is through hematogenous spread often from a primary focus. 50% show no pulmonary radiographic changes. 

The mycobacterium lodges itself in the joint synovium or the metaphysis leading to marked joint effusion and thickening of the synovial membrane. Then the granulation tissue expands inwards from the joint periphery causing erosion at the bare areas of bone and the surface of the articular cartilage. In untreated cases, further erosion occurs and progressive of the destruction of the articular surfaces. Later para-articular soft tissue extension may occur with the formation of cold abscesses and sinuses.

Synovial thickening shows low to intermediate signal on T2 weighted images. Joint effusion content includes; internal debris, septations, loose bodies and hemosiderin deposition.

Differential diagnosis: Pigmented villonodular synovitis (PVNS).

Synovial biopsy histopathology was of tuberculosis.

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.