Anterior Knee Anatomy

The quadriceps mechanism is the most important structure of the anterior aspect of the knee. The quadriceps muscle is composed of the rectus femoris, vastus medialis, vastus lateralis, and vastus intermedius. The quadriceps muscle forms a trilaminar tendon with the rectus femoris making the anterior layer, the vastus medialis and lateralis joining to comprise the middle layer, and the vastus intermedius making the deepest layer. The tendons coalesce to make a single tendon that inserts onto the top and upper sides of the patella. A portion of the rectus femoris tendon continues across the anterior aspect of the patella to join the patellar tendon (ligamentum patellae) that inserts onto the tibial tuberosity. The subcutaneous prepatellar bursa is formed in a split of the deep fascial layer in front of the patella. The infrapatellar branch of the saphenous nerve provides sensation to the front of the knee. The medial and lateral patellar retinacula help to stabilize the patella in the trochlear groove (patellar surface of femur).