What is the meaning of extraarticular?
Extraarticular is an anatomical term used to indicate structures related to the joint outside the joint. Although there are several joint classifications, the joints are usually formed by adjacent surfaces of two or more joint bones. The joints also have intra -articular spaces that contain connective tissue, cartilage, joint capsules filled with liquid or more than one of the above. Finally, outside the articular space of the joint, there is no bones immediately between the bones, but on the outside of the joint itself, often filled with soft tissues, such as the ligaments that surround the joint and hold the bones together. Typically, there are a membrane -lined cavity filled with liquid in the intrarticular area of the joint called the joint capsule, which also contains cartilage to prevent the bone in direct contact between themselves. The first layer on the outside joint capsules is included in the extraarticular structure and is a fibrous membrane that protects the joint. This membrane is mainly made of collagenH and elastin fibers, which is similar to the composition to ligaments.
bonds are also found in the extraarticular space and can be continuous with the fibrous membrane surrounding the joint. The function of the bindings is primarily and the most important thing is to hold the bone together and provide joint stability. For example, in the knee, Golamium or joint joint, collateral bonds, they take place vertically along both sides of the joint and help them stabilize against the side forces on the knee, such as a football player who collides with the side of another player's foot.
Many joints, including knee, contain several accessories in their extraarticular space. One such tissue is Bursa. As small pillows full ofsynovial fluid instead of feathers, Bursae is located on the outside of the joints and reduces friction between external joint structures, such as between the bone and the muscle tendon that passes over it. Another structure of the joint of accessories isA fat pad, a pillow of adipose tissue or fat that fills the gap between neighboring bones, a space similar to a weak point in the armor suit. It helps to eliminate wearing on articular cartilage, as shown in the knee joint between the knees and the tibia in the leg.
The articulation surfaces of the bones in the joint can be considered in itself as an exceptional structures. These surfaces can be flat and close together to allow sliding movements, or they can fit around them, such as pieces of puzzles and create the movement of several directions. Muscle tendons are also sometimes calculated as extraarticular tissues that only pass to the outside of the joints and allow joint movement. The tendons attach the muscles to the bone and the retractiveness when the muscle is withdrawing, causing the joint to move.