The Knee joint:)The knee joint joins the thigh with the leg and consists of two articulations; one between the femur and tibia (tibiofemoral joint), and the other between the femur and patella (patellofemoral joint). It is the largest joint in the human body. The knee is a modified hinge joint, which permits flexion and extension as well as slight internal and external rotation. The knee joint is vulnerable to injury and to the development of osteoarthritis.