The knee joint is the largest and strongest joint in the human body. It is where the thigh bone (femur), the shin bone (tibia) and the kneecap (patella) are connected. A complex ligamentous apparatus and cartilage surfaces ensure smooth joint function.
Author
Leading Medicine Guide Editors
Article overview
The knee joint
The knee joint enables flexion and extension of the leg as well as moderate inward and outward rotation (internal and external rotation) when flexed. The movements are guided and stabilized by menisci, ligaments, tendons and muscles. Important blood vessels and nerves run through the popliteal fossa at the back of the knee joint.
The articular cartilage
In a healthy person, the bones of the knee joint are covered by a whitish layer of cartilage several millimeters thick on the contact surfaces. This articular cartilage enables unproblematic and pain-free mobility of the knee joint. It consists of living cartilage cells (chondrocytes) that are embedded in a matrix tissue.
The cartilage can become dry and brittle as a result of natural ageing processes and incorrect loading, as well as malnutrition of the cartilage due to lack of movement. This increases the risk of injury and wear and tear. Cartilage surgery can then be considered as a treatment method.
Find Specialists for Knee surgery
The menisci (inter-articular discs)
There is a joint gap between the round-ended femur (femoral condyles) and the almost straight tibial plateau, in which the two menisci (plural of meniscus) are located:
- the inner meniscus (medial meniscus) and
- the outer meniscus (lateral meniscus).
As the medial meniscus is firmly attached to the medial ligament and the joint capsule and therefore has less mobility than the lateral meniscus, it is more susceptible to injury(meniscus tear). If you are looking for a knee specialist in Berlin, you will find it here.
The ligaments and tendons of the knee joint
The ligaments of the knee play an important role. Without them, the femur and tibia would not be connected to each other. The knee joint is stabilized forwards and backwards by the two cruciate ligaments (anterior and posterior cruciate ligaments).
The inner and outer collateral ligaments provide lateral limitation of the knee joint and the joint capsule. The patellar ligament complements the patellar tendon. The patellar tendon is the most important tendon in the knee joint. The kneecap (patella) is embedded in it.
The joint capsule
The knee joint is surrounded by a strong joint capsule. This capsule produces a fluid that nourishes the joint cartilage and reduces the rubbing of the cartilage surfaces against each other.
Diseases and injuries to the knee joint
The knee joint is primarily subject to arthrotic changes(knee osteoarthritis or gonarthrosis - joint wear and tear in the knee) and ligament injuries (especially cruciate ligament tears). Knee osteoarthritis can be the result of misalignment of the legs (e.g. knock knees or bow legs), incorrect weight-bearing or injuries.
Cartilage damage to the knee does not necessarily lead to knee osteoarthritis, as there are a variety of options available for treating knee cartilage damage. If knee osteoarthritis is present, an artificial knee joint (knee prosthesis) can restore a great deal of quality of life.
Find Specialists for Knee endoprosthetics
Sports injuries often affect the knee. In addition to a torn cruciate ligament (cruciate ligament rupture), tears to the collateral ligaments, injuries to the menisci and the detachment of a piece of cartilage bone are also possible.
Other diseases and injuries in the knee area include arthrofibrosis, patella fract ures and Baker's cysts.
