What is the knee joint?
The knee is a multi-part structure consisting of bone, cartilage, muscles, tendons and ligaments. When we speak of the knee joint (articulatio genus), strictly speaking this means only the adjacent bones, cartilage and the capsule holding the joint together. Actually, the knee joint consists of two joints: the patellar joint (femoropatellar joint, articulatio femoropatellaris) between the femur and the patella, and the popliteal joint between the femur and the tibia (femorotibial joint, articulatio femorotibialis).
Bone
The three bony components of the knee joint include the femur, patella and tibia, but not the fibula. A total of six articular surfaces lie close together here: the patella, three surfaces of the femur and two of the tibia.
Cartilage
The ends of the femur and tibia (condyles) are covered by articular cartilage (hyaline cartilage). Between the two bones are two discs of cartilage, the menisci (fibrocartilage). The back of the patella is also covered with cartilage.
Joint capsule
Despite their spatial proximity, the thigh bone (femur) and the shin bone (tibia) only meet directly in a few places. The joint head sits relatively “loosely” in the socket and therefore needs numerous ligaments (ligaments) to protect the knee from dislocation. Although these are not located directly in the joint space of the knee, they are critical to its function. Among the most important are:
A number of tendons near the knee joint are necessary for force transmission:
- Patellar tendon
- Biceps tendon
- Quadriceps tendon
Numerous muscles (such as the hamstring and tibial muscles) attach to the knee joint. Below the kneecap and to the side of the knee joint are bursae that reduce friction between the skin, tendons, muscles and ligaments with the bone. The knee joint is supplied by arteries and nerves and is equipped with lymph nodes.
What is the function of the knee joint?
Where is the knee joint located?
The knee joint is the articulated connection between the upper and lower leg.
What problems can the knee joint cause?
The knee joint and its surrounding structures are susceptible to numerous injuries, inflammation, and degenerative processes (wear and tear).
Common traumatic injuries to the knee joint include:
- Contusion (contusion): Ligaments, cartilage, bone, muscle, and skin are bruised by impact, bump, blow, or fall.
- Strain (distortion): fine tears in tissue due to overstretching.
- Capsule/ligament tear: Result of a severe strain. In the case of strong ligaments, their anchoring to the bone usually tears (bony avulsion).
- Meniscus tear
- Dislocation: Joint surfaces no longer stand correctly after excessive rotation; often favored by slack ligaments; usually associated with ligament or capsule tear.
Inflammatory processes that can affect the knee are:
- Bone inflammation (osteitis, osteomyelitis).
- Joint inflammation (arthritis): rheumatism, gout (hyperuricemia)
- Inflammation of the bursa (bursitis)
- Inflammation of the joint mucosa (synovitis)
- Tendosynovitis (inflammation of the tendon sheath)
