The lateral patellar plica is a fold of synovial tissue located on the lateral aspect of the knee joint, running along the inner surface of the lateral patellar facet. Its function is generally considered minor, serving as a synovial fold that allows smooth gliding of the patella during knee movement. Clinically, it becomes significant when thickened or inflamed, potentially causing lateral knee pain, catching, or symptoms of plica syndrome, which may require conservative or surgical management.