Synovial plicae represent inward folds of the synovial lining of the knee joint capsule, which are considered vestiges of a membranous knee joint partition present during foetal development. Three to four such folds are found with regularity in the human knee, but most are asymptomatic and of little clinical consequence. Plicae are more commonly seen in young adults, and can be an important cause of anteriorknee pain, presenting with a plethora of symptoms.
Plica Synovialis Patellaris (ligamentum mucosum) isfound in the intercondylar notch,
extends from the femur to the tibial plateau covering the anterior cruciate ligament.
Plica synovialis suprapatellaris (suprapatellar plica) is found in the suprapatellar space, extending from the medial capsule of the knee toward the lateral capsule with various patterns.
Plica synovialis mediopatellaris (medial plica) extends from the infrapatellar fat pad to the medial capsule of the knee, in the coronal plane.
Plica synovialis lateropatellaris (lateral plic) is rarely seen and extends from the infrapatellar fat pad to the lateral capsule of the knee, in the coronal plane.