The largest joint in the body, the knee moves like a hinge, allowing you to sit, squat, walk or jump and is made of three bones - femur or the thigh bone, tibia or the shin bone and the patella or the kneecap. The knee is a joint that has three compartments. This joint has an inner (medial) and an outer (lateral) compartment. The kneecap (patella) joins the femur to form a third compartment called the patellofemoral joint. The thigh bone (femur) meets the large shinbone (tibia) forming the main knee joint. The knee joint is surrounded with ligaments strapping the inside and outside of the joint (collateral ligaments) as well as crossing within the joint (cruciate ligaments) providing stability and strength to the knee joint. The meniscus is a thickened cartilage pad between the two joints formed by the femur and tibia. The meniscus acts as a smooth surface for motion and absorbs the load of the body above the knee when standing. This anatomy of the knee is reflective of its function in ambulation. Knee stability and pain-free range of motion are important in maintaining daily function. Causes for knee pain are often associated with stress on the knee joint such as during sports activities, such as while running, playing soccer or skiing as also due to the repeated stress due to the wear and tear arising due to age. Most commonly, overuse, age, and traumatic injuries cause structural damage to the knee that may limit its function.
