Acetabular labrum

Acetabular Labrum

Diagram of the hip joint, showing the acetabular labrum.

The acetabular labrum is a ring of cartilage that surrounds the acetabulum of the hip joint. It is a fibrocartilaginous structure that plays a crucial role in maintaining the stability and function of the hip joint.

Anatomy

The acetabular labrum is attached to the rim of the acetabulum, which is the cup-shaped socket of the pelvis that accommodates the head of the femur. The labrum is triangular in cross-section and is composed of dense fibrous tissue. It extends the depth of the acetabulum, increasing the surface area of the joint and providing a seal that helps to maintain the negative intra-articular pressure within the joint.

Function

The primary functions of the acetabular labrum include:

• Joint Stability: The labrum deepens the acetabulum, enhancing the stability of the hip joint by providing a larger surface area for the femoral head to articulate with.
• Shock Absorption: It acts as a cushion, absorbing forces transmitted through the hip joint during activities such as walking, running, and jumping.
• Joint Lubrication: The labrum helps to maintain the synovial fluid within the joint, which is essential for lubrication and nutrition of the articular cartilage.
• Pressure Distribution: It aids in the even distribution of pressure across the joint surfaces, reducing wear and tear on the articular cartilage.

Clinical Significance

Injuries to the acetabular labrum, such as tears, can lead to hip pain and dysfunction. Labral tears are often associated with femoroacetabular impingement (FAI), a condition where abnormal contact between the femur and acetabulum leads to damage. Symptoms of a labral tear may include pain in the hip or groin, clicking or locking of the joint, and decreased range of motion.

Diagnosis of labral tears typically involves a combination of physical examination, imaging studies such as MRI, and sometimes diagnostic arthroscopy. Treatment options vary depending on the severity of the tear and may include physical therapy, anti-inflammatory medications, or surgical intervention such as arthroscopic labral repair.

Related Pages

• Hip joint
• Femoroacetabular impingement
• Cartilage
• Pelvis