Henry Gray (18251861). Anatomy of the Human Body. 1918.
Synovial Membrane.The synovial membrane of the knee-joint is the largest and most extensive in the body. Commencing at the upper border of the patella, it forms a large cul-de-sac beneath the Quadriceps femoris (Figs. 350, 351) on the lower part of the front of the femur, and frequently communicates with a bursa interposed between the tendon and the front of the femur. The pouch of synovial membrane between the Quadriceps and front of the femur is supported, during the movements of the knee, by a small muscle, the Articularis genu, which is inserted into it. On either side of the patella, the synovial membrane extends beneath the aponeuroses of the Vasti, and more especially beneath that of the Vastus medialis. Below the patella it is separated from the ligamentum patellæ by a considerable quantity of fat, known as the infrapatellar pad. From the medial and lateral borders of the articular surface of the patella, reduplications of the synovial membrane project into the interior of the joint. These form two fringe-like folds termed the alar folds; below, these folds converge and are continued as a single band, the patellar fold (ligamentum mucosum), to the front of the intercondyloid fossa of the femur. On either side of the joint, the synovial membrane passes downward from the femur, lining the capsule to its point of attachment to the menisci; it may then be traced over the upper surfaces of these to their free borders, and thence along their under surfaces to the tibia (Figs. 351, 352). At the back part of the lateral meniscus it forms a cul-de-sac between the groove on its surface and the tendon of the Popliteus; it is reflected across the front of the cruciate ligaments, which are therefore situated outside the synovial cavity.