Knee Medial Parapatellar Plica

plica synovialis mediopatellaris

The medial parapatellar plica (medial shelf) is a synovial fold running from the suprapatellar pouch medially and inferiorly across the medial patellofemoral compartment to insert into the infrapatellar fat pad. It is a normal embryological remnant present to some degree in approximately 50-70% of knees. When thickened and fibrosed, it can impinge between the patella and the medial femoral condyle during knee flexion.

Region: Knee

Clinical Relevance

Clinical Notes

Plica syndrome from a pathologically thickened medial plica produces anteromedial knee pain, a palpable band medial to the patella, a clicking sensation at 30-60 degrees of knee flexion, and pseudo-locking. It is commonly confused with medial meniscal tear or patellofemoral syndrome. MRI may demonstrate a thickened medial plica, and diagnostic arthroscopy is definitive. Arthroscopic plica resection is simple and effective in symptomatic cases that fail conservative management.

Pathology

Common Injuries & Conditions

Plica Syndrome

A thickened fibrosed medial parapatellar plica impinges between the medial femoral condyle and the medial patellofemoral joint during knee flexion, producing anteromedial knee pain, a palpable snapping band, and pseudo-locking that mimics meniscal pathology, treated by arthroscopic plica resection.