The acetabulum is a large, hemispherical-shaped cavity on the lateral side of the hip bone. The hip joint is created when the head of the femur connects to the pelvis at the acetabulum. Here, let’s discuss the structure and function of the acetabulum.
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What Is Acetabulum?
The concave pelvic surface is known as the acetabulum or cotyloid cavity. The hip joint is created when the head of the femur connects to the pelvis at the acetabulum.
Ilium, ischium and pubis are the three components that make up each pelvic bone. At birth, these bones are joined by cartilage in the acetabulum region; later, between the ages of 16 and 18, they fuse together to form a single bone.
Acetabulum – Anatomy
The huge cup-shaped acetabulum for femoral head articulation is located on the lateral surface of the pelvic bone in the region where the ilium, ischium and pubis fuse. A layer of slick tissue known as articular cartilage, which is lubricated by a thin film of synovial fluid, lines the surfaces of the femoral head and acetabulum that are well-fitting to one another.
- A noticeable notch on the inferior side of the acetabulum’s margin serves as its marking (acetabular notch).
- The acetabulum’s wall is made up of articular and nonarticular components.
- The nonarticular component is rough and creates a tiny circular depression called the acetabular fossa in the acetabular floor’s inferior and central parts. The acetabular notch and fossa are one continuous structure.
- The articular surface is large and encompasses the acetabular fossa’s anterior, posterior and superior edges. The anterior, posterior and superior portions of the acetabulum have an articular surface that resembles a horseshoe, also known as a lunate surface. It articulates with the femur’s head to form the hip joint and is lined with hyaline cartilage.
- Blood veins and nerves run through the acetabular notch, while the ligament of the femur’s head has an attachment point in the acetabular fossa.
- The acetabulum’s rim is slightly elevated (the acetabular labrum) by means of a fibrocartilaginous collar. The labrum crosses the acetabular notch inferiorly, acting as the transverse acetabular ligament, transforming the notch into a foramen. Thus, it deepens the acetabular cavity.
Also Check: MCQs on Types of Joints
The hip joint is created by the articulation of the acetabulum and the femoral head. When these structures work together, we can easily run, walk and move freely. Similar to the shoulder girdle, the pelvic girdle places the hip in the right place for movement. The pelvis is not joined, whereas the shoulder girdle contains a variety of joints. The pelvis can still rotate in all three planes, though. The acetabular position is altered by pelvic rotation so that it is pointed in the direction of the following femoral movement.
The acetabulum is obliquely inclined toward the front. An acetabulum that is misaligned does not adequately protect the femoral head, which can lead to early onset osteoarthritis and chronic dislocation.
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