Suprapatellar Plica

plica synovialis suprapatellaris

The suprapatellar plica is a synovial fold at the superior pole of the patella forming the boundary between the suprapatellar pouch and the main knee joint cavity. It is a normal embryological remnant of the synovial membrane partition. When thickened or fibrotic, it can impinge between the patella and the femur during knee flexion.

Region: Thigh

Biomechanics

Function & Actions

Remnant synovial fold separating the suprapatellar pouch from the main joint cavity; in pathological states can impinge on the patellofemoral joint.

Clinical Relevance

Clinical Notes

Pathological suprapatellar plica syndrome produces anterior knee pain above the patella, a palpable snap during flexion-extension, and a tender cord at the superior patellar border. Arthroscopy identifies the plica and allows resection. It is most symptomatic between 30-60 degrees of flexion when it is compressed between the patella and trochlea. MRI may show the thickened plica but arthroscopy remains the gold standard for diagnosis and treatment.

Pathology

Common Injuries & Conditions

Suprapatellar Plica Syndrome

Anterior knee pain from fibrotic thickening of the suprapatellar synovial fold impinging between the patella and trochlea during flexion, treated by arthroscopic plica resection.