Coxal articulation

Coxal articulation, also known as the hip joint, is a ball-and-socket type of synovial joint that connects the pelvis to the femur, the thigh bone. This joint is one of the most important in the human body, allowing for a wide range of movement in multiple directions while also supporting the weight of the upper body in both static and dynamic postures. The coxal articulation is crucial for various activities such as walking, running, and jumping.

Anatomy

The hip joint is formed by two main components: the acetabulum, a deep cup-shaped cavity on the pelvis, and the head of the femur, which fits into the acetabulum. The surfaces of both the acetabulum and the femoral head are covered with a smooth tissue called articular cartilage, which reduces friction and absorbs shock. Surrounding the joint is a strong capsule reinforced by ligaments that provide stability. The synovial membrane lining the capsule produces synovial fluid, which lubricates the joint.

Ligaments of the Coxal Articulation

Several key ligaments contribute to the stability of the hip joint:

• The iliofemoral ligament, which prevents hyperextension
• The pubofemoral ligament, which limits excessive abduction and extension
• The ischiofemoral ligament, which resists excessive internal rotation

Muscles

A number of muscles are involved in the movement of the hip joint, including the gluteal muscles for abduction, the adductor muscles of the thigh for adduction, the quadriceps femoris for extension, and the hamstrings for flexion.

Function

The primary function of the coxal articulation is to support the weight of the upper body in both static (standing) and dynamic (walking or running) conditions, and to provide significant mobility for the lower extremities. The range of motion of the hip joint is extensive but is limited by the depth of the acetabulum, the strength and tightness of the surrounding ligaments and muscles, and the shape of the femoral head and neck.

Pathology

Common pathologies affecting the coxal articulation include osteoarthritis, due to wear and tear on the articular cartilage; rheumatoid arthritis, an autoimmune condition affecting the synovial membrane; and hip fractures, which are particularly common in older adults due to falls. Hip dysplasia is a condition present at birth that can lead to problems in later life if not treated.

Treatment

Treatment for disorders of the coxal articulation varies depending on the condition. Non-surgical options include physical therapy, anti-inflammatory medications, and lifestyle modifications. In severe cases, surgical interventions such as hip replacement surgery may be necessary.