The medial and lateral menisci are fibrocartilage structures in the knee that serve two functions: These are the femoral, tibial and common fibular nerves. The nerve supply, according to Hilton’s law, is by the nerves which supply the muscles which cross the joint. The blood supply to the knee joint is through the genicular anastomoses around the knee, which are supplied by the genicular branches of the femoral and popliteal arteries. The inferior surface of the femur and superior surface of the tibia is shown. Fig 2 - More detailed view of the bony surfaces. The ACL is also affected, which completes the ‘unhappy triad’. A lateral force to an extended knee, such as a rugby tackle, can rupture the medial collateral ligament, damaging the medial meniscus in the process. Unhappy Triad (Blown Knee)Īs the medial collateral ligament is attached to the medial meniscus, damage to either can affect both structure’s functions.
#Areas where two or more bones join together skin
Similarly, friction between the skin and tibia can cause the infrapatellar bursae to become inflamed, resulting in what is known as clergyman’s knee (classically caused by clergymen kneeling on hard surfaces during prayer). Bursitisįriction between the skin and the patella cause the prepatellar bursa to become inflamed, producing a swelling on the anterior side of the knee. If there is movement, the ligament has been torn. This is where the clinician holds the knee in flexed position, and pushes the tibia posteriorly.
To test for PCL damage, perform the posterior draw test. The posterior cruciate ligament can also be torn by hyperextension of the knee joint, or by damage to the upper part of the tibial tuberosity. This is often seen in car accidents, where the knee hits the dashboard. This occurs when the knee is flexed, and a large force is applied to the shins, pushing the tibia posteriorly. The most common mechanism of posterior cruciate ligament (PCL) damage is the ‘dashboard injury’.
The anterior cruciate ligament (ACL) can be torn by hyperextension of the knee joint, or by the application of a large force to the back of the knee with the joint partly flexed. To test for this, you can perform an anterior drawer test, where you attempt to pull the tibia forwards, if it moves, the ligament has been torn. If the medial collateral ligament is damaged, it is more than likely that the medial meniscus is torn, due to their attachment. Pain on medial rotation indicates damage to the medial ligament, pain on lateral rotation indicates damage to the lateral ligament. It is caused by a force being applied to the side of the knee when the foot is placed on the ground.ĭamage to the collateral ligaments can be assessed by asking the patient to medially rotate and laterally rotate the leg. Injury to the collateral ligaments is the most common pathology affecting the knee joint. It prevents posterior dislocation of the tibia onto the femur.Ĭlinical Relevance: Injury to the Knee Joint Collateral Ligaments
Patellar ligament – a continuation of the quadriceps femoris tendon distal to the patella.The major ligaments in the knee joint are: