térdízületnél

The térdízület, or knee joint in English, is a complex hinge joint in the leg that connects the thigh bone (femur) to the shin bone (tibia). It is one of the largest and most crucial joints in the human body, enabling a wide range of motion for walking, running, jumping, and squatting. The joint is comprised of several key structures that work together to ensure smooth and stable movement.

The main articulating surfaces are the condyles of the femur and the tibial plateau. These bony surfaces are covered by articular cartilage, a smooth, slippery tissue that reduces friction and absorbs shock. Between the femur and tibia lie two C-shaped pieces of fibrocartilage called menisci, the medial meniscus and the lateral meniscus. These menisci act as shock absorbers and stabilizers, deepening the tibial plateau to better fit the femoral condyles.

Ligaments play a vital role in the stability of the knee joint. The four primary ligaments are the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL), located within the joint, and the medial collateral ligament (MCL) and lateral collateral ligament (LCL), on the sides of the joint. These ligaments prevent excessive forward or backward movement of the tibia relative to the femur and limit sideways motion.

The kneecap, or patella, is a small, triangular bone that sits in front of the femur. It articulates with a groove on the femur called the trochlear groove. The patella acts as a lever, improving the efficiency of the quadriceps muscles in extending the leg. The entire joint is enclosed within a capsule, which is lined with a synovial membrane that produces synovial fluid. This fluid lubricates the joint, allowing for effortless movement. Surrounding muscles, such as the quadriceps and hamstrings, also contribute to knee stability and movement.