Suprapatellar Bursa

bursa suprapatellaris

The suprapatellar bursa is a large synovial sac superior to the patella, lying between the quadriceps tendon anteriorly and the anterior surface of the distal femur posteriorly. In most adults it communicates freely with the knee joint through an opening in the suprapatellar membrane, making it effectively the superior extension of the knee joint synovial cavity. In the fetal period it is a separate structure, and occasionally fails to communicate, remaining as a distinct bursa into adult life.

Region: Knee

Clinical Relevance

Clinical Notes

The suprapatellar pouch is the most commonly distended structure in knee joint effusion, producing the characteristic fluctuant fullness above the patella that descends and refills with the patellar ballottement test and the bulge sign. The pouch is the site of initial aspiration for knee joint effusion. Loose bodies, synovial chondromatosis, and pigmented villonodular synovitis preferentially involve the suprapatellar pouch. In knee arthroplasty, the suprapatellar approach through the quadriceps tendon provides good exposure while theoretically reducing eversion forces on the extensor mechanism.

Pathology

Common Injuries & Conditions

Suprapatellar Impingement in TKA

Suprapatellar pouch scarring or fibrosis after total knee arthroplasty produces anterior knee pain with limited flexion, managed with arthroscopic lysis of adhesions and suprapatellar pouch debridement to restore flexion arc.

Isolated Suprapatellar Bursitis

When the suprapatellar membrane remains intact without communication to the joint, a separate suprapatellar bursitis can develop from direct trauma or repetitive kneeling, producing pain and swelling above the patella without knee joint effusion on arthrocentesis.