“The knee joint is one of the most complicated and critical joints of the human body. The knee has to bear the entire body weight, shift balance and adjust direction of movement all smoothly and in efficient coordination. It is not surprising that injuries occur to this particular joint. The primary elements of the knee include the large bone structures: the femur, patella, tibia, and the fibula. What moves the bones of course are the muscles: flexors (biceps femoris, semimembraneous, semitendinous, sartorius, gracilis and extensors quadriceps and patellar. Now, within those larger structures are smaller but nonetheless critical components: the various ligaments which stabilize the bones and muscles such as the medial and lateral Collateral Ligaments and the Anterior and Posterior Cruciate Ligaments usually termed ACL and PCL.”