Knee Effusion

Knee Effusion

Structure of the Knee Joint

The knee joint is a synovial joint that allows people to walk, run, and climb stairs. This joint performs knee bending and unbending as well as some rotational movements.

The knee consists of 2 joints, the tibiofemoral joint and the patellafemoral joint;

The main joint of the knee is the tibiofemoral joint and most of the movements are made through this joint. The tibiofemoral joint consists of the tibia and femur bones.
The tibia is one of the two bones in the leg, lying between the knee and ankle. It is a thick and strong bone that carries the body weight. Its upper end articulates with the thigh bone, forming the main joint of the knee.
The femur (thigh bone) is one of the longest and strongest bones in our body. It plays an important role in the realization of the functions we need in daily life such as walking, standing, sitting and getting up. Since it is located between the hip and knee joint, it provides the movements in the hip and knee joint. The muscles attached to the femur bone are very important for walking activity.
The other joint of the knee is the patella-femoral joint. 
It consists of the patella (kneecap) and femur bone. The joint surface takes up less space than the tibiofemoral joint.
The patella is located in front of the knee joint and protects the joint against impact. It provides an adhesion zone for the muscles, allowing increased movement of the knee joint. It also allows the loads on the knee joint to be met more comfortably.
The knee joint is supported by cartilaginous menisci. Menisci increase the harmony between the bones, increase the surface of the knee joint, absorb shocks to the knee and increase the stability of the knee.

The knee joint is supported by ligaments that give it stability. Ligaments in the knee are responsible for protecting the knee during movements. They allow controlled movements. 

There are many muscles that enable the movements in the knee joint. 

These muscles allow functions such as bending and unbending the knee, locking the knee, rotating the leg inward and outward during activities such as walking, running, sitting, bending, climbing up and down stairs. 

The knee joint faces are covered with cartilage. Thanks to the cartilage structure, lubrication is provided between the bones and knee joint movements are performed comfortably. 

The knee joint contains joint fluid (synovial fluid) that lubricates the joint surfaces. This fluid is clear, transparent and contains water. It is secreted from the synovial membrane covering the joint surface. 

The joint fluid provides nourishment to the cartilage structure. Hyaluronic acid in the joint fluid increases the lubricity and durability of the joint. Thanks to the joint fluid, the friction between the moving bones is reduced and the movements in the knee are made without difficulty. 

Decreased joint fluid in the knee or deterioration of the structure of the joint fluid is called fluid loss in the knee. Loss of fluid in the knee can lead to increased friction on the joint surfaces and wear and destruction of cartilage tissue. 

If left untreated, fluid loss in the knee is a health condition that reduces the quality of life of patients and prevents their participation in social life. 

Patients consult a doctor for reasons such as pain, swelling and limitation of movement in the knee for a while. The most important cause of fluid loss in the knee is osteoarthritis (calcification). 

In addition, fluid loss in the knee also prepares the ground for arthritis and joint damage. Because of this close relationship between these two health conditions, patients diagnosed with arthritis often refer to arthritis as fluid loss in the knee. However, there is sometimes an increase in joint fluid in arthritis.