Bursae of Knee Joint (Left)

Description

Bursae are sac-like structures, with an inner synovial membrane, that produces a thin film of synovial fluid. They aid in reducing friction between moving tissues of the body, such as between tendon and bone, ligament and bone, tendons and ligaments, and between muscles.

Bursae around the knee joint can be grouped as those that occur around the patella and those that occur elsewhere. Examples of bursae around the patella include the prepatellar bursa, the superficial and deep infrapatellar bursae, and the suprapatellar bursa.

—The prepatellar bursa is located between the patella and the overlying skin.

—The infrapatellar bursae may be subcutaneous or deep. The subcutaneous infrapatellar bursa is located between the patellar ligament and the overlying skin, whereas the latter is located between the patellar ligament and the tibia.

—The suprapatellar bursa is located between the quadriceps tendon and the distal femur.

On the contrary, bursae that are not anatomically close to the patella include the anserine bursa, the iliotibial tract bursa, medial and lateral subtendinous bursae of gastrocnemius and biceps femoris, semimembranosus bursa, and the gastrocnemius-semimembranosus bursa (Chatra, 2012). The anserine bursa separates the tendons of sartorius, gracilis, and the semitendinosus muscles from the tibial collateral ligament and the bony surface of the medial tibial condyle.

Inflammation of a bursa is called bursitis. Common causes could include trauma, infection, overuse, and hemorrhage. Other causes include systemic illness like collagen vascular disease and inflammatory arthropathy; in some instances, the cause is unknown. Certain occupational causes include prepatellar bursitis or housemaid's knee and superficial infrapatellar bursitis, which is synonymous with clergyman's knee.