Greater Austin Orthopaedics
This joint complex is made up of three bones, the femur (thigh bone), tibia (leg bone), and patella (kneecap).
There are two joints in the knee, the patellofemoral joint between the kneecap and the end of the thigh bone, and the tibiofemoral joint between the end of the thigh bone and top of the leg bone.
Four ligaments stabilize the tibiofemoral knee joint, the medial collateral ligament (MCL), lateral collateral ligament (LCL), anterior cruciate ligament (ACL), and posterior cruciate ligament (PCL). Two disc shaped cartilage structures called the meniscus act as a shock absorbing cushion between the femur and the tibia. Articular cartilage is the smooth cartilage cap on the end of the bones in the joint which provides a low friction surface for maximum joint function. The knee joint extends (straightens out) when the quadriceps muscles contract, and flexes when the hamstring muscles contract. The quadriceps muscle and tendon attach to the patella (kneecap), which increases the lever arm and power of contraction of the quadriceps.
Anterior Cruciate Ligament (ACL) tear
Anterior Cruciate Ligament (ACL) tear - ligament inside the knee joint that attaches the thigh and leg bone, and prevents abnormal rotation and sliding of the leg bone on the thigh bone. Injury to this ligament can occur with contact or noncontact sports, car accidents, falls, work injuries.
Medial Collateral Ligament (MCL) sprain
Medial Collateral Ligament (MCL) sprain - ligament outside the knee joint attaching the inside of the thigh bone to the leg bone. Injury to this structure typically results from a direct blow to the outside of the knee, causing the knee to buckle inward.
Meniscus tear
Meniscus tear - fibrocartilage disc shaped structure which is a shock absorbing cushion between the end of the thigh bone and top of the leg bone. Sudden trauma or gradual degeneration can lead to a tearing of this structure.
Patellofemoral knee pain
Patellofemoral knee pain - common source of knee pain resulting from the joint between the kneecap and the end of the thighbone in the front of the knee.
Patellar tendonitis ("Jumper's knee")
Patellar tendonitis ("Jumper's knee") - this is a condition involving inflammation or degeneration of the tendon which attaches the kneecap to the top of the leg bone.
Distal Iliotibial (IT) tendonitis
Distal Iliotibial (IT) tendonitis - inflammation or degeneration of the tendon which runs over the outside part of the thigh as it passes over the end of the femur bone. This condition is commonly seen in runners, patients with slight differences in leg lengths, or who have valgus knee alignment ("knock-kneed"). Signs/symptoms include pain over the outside part of the knee, especially in certain position of knee flexion.
Articular Cartilage injuries/Loose Bodies
Articular Cartilage injuries/Loose Bodies - acute trauma or gradual deterioration involving the cartilage surface on the end of the bones. Associated injuries from a trauma can include meniscus, ligament, or bone injury.
