Hip Replacement

Arthroplasty is a surgical procedure in which diseased parts of the hip joint are replaced by new artificial parts called prostheses. Although this procedure was once reserved for people over 60, who live less active lives, it is now being successfully used on much younger people thanks to technology that has improved the artificial parts, allowing them to withstand more stress and strain. Today, overall health and activity level, not age, are factors used to determine the success of hip replacement.

The American Academy of Orthopaedic surgeons estimates 120,000 hip replacement operations are performed each year, most often because of the wearing down of hip joints from osteoarthritis. Rheumatoid arthritis, avascular necrosis, injury, and bone tumors may also lead to the breakdown of the hip joint and the necessary replacement surgery.

Prior to replacement surgery, other alternatives such as walking aids and various non-surgical therapies, including exercise and medication should be explored. A muscle-strengthening program can sometimes help improve positioning of the hip, therefore relieving pain. Additionally, there are medications, such as nonsteroidal anti-inflammatory drugs, available that may help with pain relief. In a small number of cases, steroids may be prescribed by to reduce joint inflammation. However, if these solutions are not effective in relieving pain or improving the function of the hip and if persistent pain and disability begin to interfere with daily life, hip replacement may be an option.

During hip replacement, the diseased bone tissue and cartilage are removed from the hip joint. Healthy parts of the hip are left intact. The head of the femur (the ball of the joint) and the acetabulum (the socket) are replaced with artificial parts that allow a natural, gliding motion of the joint.

A special glue or cement may be used to bond the new parts of the hip joint to the existing healthy bone. If cement is not used, the artificial parts are made of porous material that allows the bone to grow into the pores and hold the new parts in place. Another alternative may be to use a cemented femur part and an uncemented acetabular part. There are advantages and disadvantages to each of the procedures that can be discussed with your doctor.

As could be expected, movement is limited immediately following surgery. Steps are taken to ensure the hip remains in the correct position. Physical therapy may teach exercises, such as contracting and relaxing certain muscles that can begin strengthening the hip. The artificial hip has less range of movement than a healthy hip. Physical therapists teach proper techniques for simple activities such as bending and sitting, to prevent injury to the new hip.

Most people spend about 3-4 days in the hospital following a hip replacement. Full recovery usually takes between three and six months, depending on overall health and the success of rehabilitation.

Although advances in surgical techniques have greatly reduced the risks in the surgery, there are complications that can occur. One of the most common problems that happens after hip replacement surgery is hip dislocation. Because the artificial ball and socket are smaller than the normal ones, the ball can become dislodged from the socket if the hip is placed in certain positions, such as pulling the knees up to the chest. If patients follow certain limitations called hip precautions, the chances of a dislocation are reduced significantly. A common later complication is an inflammatory reaction to tiny particles that gradually wear off of the artificial joint surfaces and are absorbed by the surrounding tissues. This inflammation may trigger the action of special cells that eat away some of the bone, causing the implant to loosen. Anti-inflammatory medications or revision surgery (replacement of the artificial joint) may be recommended.

Proper exercise can help reduce joint pain and stiffness and increase flexibility and muscle strength. Many doctors recommend avoiding high-impact activities such as basketball, jogging, and tennis, which can damage the new hip or cause loosening of its parts. Recommended activities may include cross-country skiing, swimming, walking, and stationary bicycling, which can increase muscle strength and cardiovascular fitness without injuring the new hip.