The lateral synovial recess of the knee: anatomy and role in chronic Iliotibial band friction syndrome.

The tissue deep to the iliotibial band (ITB) and its relationship to the lateral knee joint capsule was studied anatomically and the histopathology of this tissue in chronic iliotibial band friction syndrome (ITBFS) was examined. Findings show that the tissue under the ITB consists of a synovium that is a lateral extension and invagination of the actual knee joint capsule and is not a separate bursa as described in the literature. Additionally, in cases of chronic ITBFS seen in young elite athletes, synovial tissue taken from this lateral synovial recess reveals histological evidence of inflammation and hyperplasia that suggests its involvement in the pathological process.