The hip is one of the body's largest weight-bearing joints.
It consists of two main parts: a ball (femoral head) at the top of your thighbone (femur) that fits into a rounded socket (acetabulum) in your pelvis. Bands of tissue called ligaments (hip capsule) connect the ball to the socket and provide stability to the joint.
The bone surfaces of the ball and socket have a smooth durable cover of articular cartilage that cushions the ends of the bones and enables them to move easily.
A thin, smooth tissue called synovial membrane covers all remaining surfaces of the hip joint. In a healthy hip, this membrane makes a small amount of fluid that lubricates and almost eliminates friction in your hip joint. Normally, all of these parts of your hip work in harmony, allowing you to move easily and without pain.
An important factor in deciding whether to have hip replacement surgery is understanding what the procedure can and cannot do. Most people who undergo hip replacement surgery experience a dramatic reduction of hip pain and a significant improvement in their ability to perform the common activities of daily living. However, hip replacement surgery will not enable you to do more than you could before your hip problem developed. Following surgery, you will be advised to avoid certain activities, including jogging and high-impact sports, for the rest of your life. You may be asked to avoid specific positions of the joint that could lead to dislocation. Even with normal use and activities, an artificial joint (prosthesis) develops some wear over time. If you participate in high-impact activities or are overweight, this wear may accelerate and cause the prosthesis to loosen and become painful.
The surgical procedure takes about an hour and a half. Your orthopedic surgeon will remove the damaged cartilage and bone and then position new metal, plastic, or ceramic joint surfaces to restore the alignment and function of your hip. Many different types of designs and materials are currently used in artificial hip joints. All of them consist of two basic components: the ball component (made of a highly polished strong metal or ceramic material) and the socket component (a durable cup made of plastic, ceramic, and an outer metal shell). Special surgical cement may be used to fill the gap between the prosthesis and remaining natural bone to secure the artificial joint.
A non cemented prosthesis has also been developed and is used most often in patients with strong bone. The prosthesis may be coated with textured metal or a special bone-like substance, which allows bone to grow into the prosthesis.
A combination of a cemented stem and a non cemented socket may be used. Your orthopedic surgeon will choose the type of prosthesis that best meets your needs.
Adapted from the American Academy of Orthopaedic Surgeons (AAOS).