Hip replacement surgery is a procedure in which a doctor surgically removes a painful hip joint with arthritis and replaces it with an artificial joint often made from metal and plastic components. It usually is done when all other treatment options have failed to provide adequate pain relief. The procedure should relieve a painful hip joint, making walking easier.

The hip is one of the most commonly replaced joints. It allows us to move our legs and bend and straighten our body. Osteoarthritis, a type of arthritis, is the main reason for Hip Replacement Surgery. Other conditions, including trauma, may also cause the need for a hip replacement.

During this procedure, your damaged hip joint is replaced with implants that recreate the ball and socket of a healthy hip. This can reduce pain and restore your hip function. Hip replacement has the success rate of over 95%, 10 years after the surgery, and over 85%, 20 years post-operation. After the surgery, over 98% patients reported complete relief from hip pain and did not required revision surgery later.

1)Total hip replacement

In a total hip replacement, part of the thigh bone (femur) including the ball (head of femur) is removed and a new, smaller artificial ball is fixed into the rest of the thigh bone. The surface of the existing socket in the pelvis (the acetabulum) is roughened to accept a new socket component that will join up (articulate) with the new ball component.

Many artificial joint components are fixed into the bone with acrylic cement. However, it's becoming more common, especially in younger, more active patients, for one part (usually the socket) or both parts to be inserted without cement. If cement isn’t used, the surfaces of the implants are roughened or specially treated to encourage bone to grow onto them. Bone is a living substance and, as long as it’s strong and healthy, it’ll continue to renew itself over time and provide a long-lasting bond. Where only one part is fixed with cement, it’s known as a hybrid hip replacement.

The replacement parts can be plastic (polyethylene), metal or ceramic and are used in different combinations:

• Metal-on-plastic (a metal ball with a plastic socket) is the most widely used combination.
• Ceramic-on-plastic (a ceramic ball with a plastic socket) or ceramic-on-ceramic (where both parts are ceramic) are often used in younger, more active patients.
• Metal-on-metal (a metal ball with a metal socket) is very occasionally used in younger, more active patients

2) Partial hip of replacement

A partial hip replacement removes and replaces the ball of the hip joint. It does not replace the socket. This surgery is most often done to repair certain types of hip fractures

The ceramic or metal ball is attached to a metal stem. This is called a hip implant. The stem is set down into the core of the thighbone (femur). It is firmly fixed in the femur in one of two ways:

• Cemented to the bone.
• Uncemented. This kind of stem has a porous coating that the bone grows into.

3)Hip resurfacing surgery Metal-on-metal hip replacements

Resurfacing the original socket and the ball of the thigh bone is a different form of hip replacement. Instead of removing the head of the thigh bone and replacing it with an artificial ball, a hollow metal cap is fitted over the head of the thigh bone. The socket part of the joint is also resurfaced with a metal component.

People who have this type of operation have a lower risk of dislocation and may be able to return to a higher level of physical activity compared with those having a conventional hip replacement.

This type of hip surgery is linked with a release of metal particles from the joint replacement materials, which may cause local inflammatory reactions and have unknown effects on your general health.

Complication rates are particularly high in older patients and in women. Metal-on-metal resurfacing isn’t suitable for people with low bone density or osteoporosis, where the bones are weakened.

Little is known about the long-term performance of these joints as the technique hasn’t been in use for as long as total hip replacements.