New insights about suprapatellar cyst

Abstract

Suprapatellar bursa is located between the quadriceps tendon and femur, and it develops before the birth as a separate synovial compartment proximal to the knee joint. By the fifth month of fetal life there is a suprapatellar septum between the knee joint cavity and suprapatellar bursa which later perforates and involutes in a way that a normal communication between the cavity of bursa and knee is established. A small portion of the embrionic septum can later lag as more or less expressed suprapatellar plica. In case when suprapatellar plica has a small communication with valve mechanism or in case of complete septum, bursa becomes a separate compartment and potential location for the suprapatellar cyst development. Magnetic resonance imaging is recognised as the gold standard in diagnosis of knee cysts because of its ability to show cystic nature of the lesion, its relationship with other anatomic structures, as well as to establish whether other knee pathologies are present. Considering treatment possibilities, majority of cysts around the knee resolve spontaneously and should be treated by aspiration and application of corticosteroids. Suprapatellar cyst is a very rare knee pathology and it can in some occasions be treated using open or arthroscopic surgery.