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Hip Anatomy & Hip Surgery

The hip joint is made up of two main bones: the femur (the long thigh bone) and the pelvis. The rounded head of the femur sits inside the pelvic acetabulum and is secured by a strong network of muscles and ligament surrounding the joint, making the hip joint one of the sturdiest joints in the human body. This strength and sturdiness means the hip joint can hold the majority of a person’s upper body weight.

Injury and the wear and tear of aging can damage the hip joint, increasing the risk for a femoral fracture or hip fracture. Understanding hip joint anatomy helps explain how hip injuries occur and why certain injuries may be more common than others.

Hip Joint: The Femur

The femur is the longest bone in the human body, and joins with the pelvis to form what is technically called the acetabulofemoral joint, more commonly known as the hip joint. Below the femoral head, where the femur joins with the acetabulum, is the neck (also called a constriction) as well as a lateral “greater trochanter,” and a lower medial “lesser trochanter.” Because of the constriction immediately below the femoral head where the bone fits into the acetabulum, the hip joint is capable of a wide range of motion. However, because of its narrow nature it is a point of weakness and a common site for fractures.

Hip Joint: The Acetabulum

The acetabulum is the concave surface where the femoral head rests, and is secured by membrane, articular cartilage and synovial fluid. Ligament and muscle also help secure the hip joint, creating a study and flexible joint.

Problems can arise with rheumatoid arthritis, for example, when excess synovial fluid builds up between the bones and causes destruction of the articular cartilage. The result is a painful hip joint that can include stiffness, swelling and inflammation of the joint.

How Total Hip Replacement Works

Hip Replacement is recommended for pathologies like hip fractures or rheumatoid arthritis. During hip replacement surgery, the hip socket is cleaned of all cartilage and arthritic bone. A plastic cup is placed in the enlarged hip socket. The top of the femur is removed and a metal ball is implanted onto the femur. A metal stem is also added onto the femur to add stability to the prosthesis. Elderly patients and patients with osteoporosis have a heightened likelihood of hip fractures, and are usually considered candidates for total hip replacement.

Find out more about total hip replacement.

Find out about Bone & Joint Institute's Computer Assisted Surgery (Robotic Surgery) technology.

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