The knee joint, which appears like a simple hinge-joint, is one of the most complex joints in the body and is more likely to be injured than any other joint. The knee is where the femur (thigh bone) meets the tibia (shin bone). Two round knobs called condyles are found on the end of the thigh bone. The kneecap (patella) glides through a special groove formed by the two condyles. As in the hip, articular cartilage covers the ends of the bones. It is about one quarter of an inch thick in most large joints. It is white and shiny with a rubbery consistency and allows the surfaces to slide against one another. It also absorbs shock and is the major component to smooth motion of the joint.
Knee and Hip Arthritis is the Silent Occupational Disease that No One Tells You About.