The extensor retinaculum, or otherwise the retinacular distracting plate, median retinaculum, prismatic ligament is an interosseous fibrous membrane in the human body that connects the inner side of the patella (small thyroid bone) with the lateral condyle of the femur. This ligament serves the function of strengthening the patella and reducing its eccentric traction force. It holds the patella over the shin. On the side of the tibia, the area of the roof of the acetabulum is attached to the patella. The medial part of the retinaculum lies in the lateral pa, and the posterior