The knee joint is composed of three bones: the femur, the tibia and the patella. The proximal tibia-fibula joint is included in the knee, but is rarely injured. Articular cartilage covers the joint surface and provides a smooth lubricated gliding surface for knee motion. The shapes of the bony articulation provide very little inherent stability. Proper function depends upon intact ligaments. This includes the anterior cruciate ligament (ACL), the posterior cruciate ligament (PCL), the medial collateral ligament (MCL), and the lateral collateral ligament (LCL). While the ACL functions as the main stabilizer to anterior knee translation, the PCL functions as the main stabilizer to posterior translation. The collateral ligaments are the main stabilizers to side to side stress. The medial and lateral menisci are located within the joint between the femur and tibia. At times they have been referred to as the "cartilage" in the knee joint, but it is important to differentiate these structures from articular cartilage which covers the ends of the bones within the joint. The menisci function as "shock absorbers" within the knee joint and also influence knee stability.
The front of the knee is protected by the patella or kneecap, which is attached to the quadriceps muscle by the quadriceps tendon and to the tibia by the patellar tendon. While the quadriceps muscle controls knee extension, knee flexion is controlled by the hamstring muscles.
- Osteochondritis Dissecans (OCD)
- Meniscus Tear
- Chondral Defects
- Knee Osteoarthritis
- Anterior Cruciate Ligament Tear (ACL)
- Hamstring Strain
- Patellar Fracture
- Proximal Tibial Fracture
- Quadriceps Tendinitis