HIP REPLACEMENT SURGERY RISKS RESULTS

Hip replacement surgery involves both short- and long-term risks.
Short-term risks
The most common risks associated with hip replacement are as follows:
• Dislocation of the new prosthesis. Dislocation is most likely to occur in the first 10–12 weeks after surgery. It is a risk because the ball and socket in the prosthesis are smaller than the parts of the natural joint, and can move out of place if the patient places the hip in certain positions. The three major rules for avoiding dislocation are: Do not cross the legs when lying, sitting, or standing; never lean forward past a 90-degree angle at the waist; do not roll the legs inward toward each other— keep the feet pointed forward or turned slightly outward.

• Deep vein thrombosis (DVT). There is some risk (about 1.5% in the United States) of a clot developing in the deep vein of the leg after hip replacement surgery because the blood supply to the leg is cut off by a tourniquet during the operation. The blood-thinning medications and TED stockings used after surgery are intended to minimize the risk of DVT.

• Infection. The risk of infection is minimized by storing autologous blood for transfusion and administering intravenous antibiotics after surgery. Infections occur in fewer than 1% of hip replacement operations.

• Injury to the nerves that govern sensation in the leg. This problem usually resolves over time. Long-term risks
The long-term risks of hip replacement surgery include:
• Inflammation related to wear and tear on the prosthesis. Tiny particles of debris from the prosthesis can cause inflammation in the hip joint and lead eventually to dissolution and loss of bone. This condition is known as osteolysis.

• Heterotopic bone. Heterotopic bone is bone that develops in the space between the femur and the pelvis after hip replacement surgery. It can cause stiffness and pain, and may have to be removed surgically. The cause is not completely understood as of 2002 but is thought to be a reaction to the trauma of the operation. In the United States, patients are usually given indomethacin (Indocin) to prevent this process; in Germany, surgeons are using postoperative radiation treatments together with Indocin.

• Changed length of leg. Some patients find that the operated leg remains slightly longer than the other leg even after recovery. This problem does not interferewith mobility and can usually be helped by an orthotic shoe insert.

• Loosening or damage to the prosthesis itself. This development is treated with revision surgery.

Normal results
Normal results are relief of chronic pain, greater ease of movement, and much improved quality of life. Specific areas of improvement depend on a number of factors, including the patient’s age, weight, and previous level of activity; the disease or disorder that caused the pain; the type of prosthesis; and the patient’s attitude toward recovery. In general, total hip replacement is considered one of the most successful procedures in modern surgery. It is difficult to estimate the “normal” lifespan of a hip prosthesis. The figure quoted by many surgeons—10 to 15 years—is based on statistics from the early 1990s. It is too soon to tell how much longer the newer prostheses will last. In addition, as hip replacements become more common, the increased size of the worldwide patient database will allow for more accurate predictions. As of 2002, it is known that younger patients and obese patients wear out hip prostheses more rapidly.

Morbidity and mortality rates
Information about mortality and complication rates following THR is limited because the procedure is considered elective. In addition, different states and countries use different sets of measurements in evaluating THR outcomes. One Norwegian study found that patients who had THR between 1987 and 1999 had a lower long-term mortality rate than the age- and gender-matched Norwegian population. A Canadian study found a 1.6% mortality rate within 30 days of surgery for THR patients between 1981and 1999. A 2002 report from the Mayo Clinic found that the overall frequency of serious complications (heart attack, pulmonary embolism, deep vein thrombosis, or death) within 30 days of THR was 2.2%, the risk being higher in patients over 70. The most important factor affecting morbidity and mortality rates in the United States, according to a 2002 Harvard study, is the volume of THRs performed at a given hospital or by a specific surgeon; the higher the volume, the better the outcomes.

Alternatives
Nonsurgical alternatives
The most common conservative alternatives to hip replacement surgery are assistive devices (canes or walkers) to reduce stress on the affected hip; exercise regimens to maintain joint flexibility; dietary changes, particularly if the patient is overweight; and analgesics, or painkilling medications. Most patients who try medication begin with an over-the-counter NSAID such as ibuprofen (Advil). If the pain cannot be controlled by nonprescription analgesics, the doctor may give the patient cortisone injections, which relieve the pain of arthritis by reducing inflammation. Unfortunately, the relief provided by cortisone tends to diminish with each injection; moreover, the drug can produce serious side effects.

Complementary and alternative (CAM) approaches
Complementary and alternative forms of therapy cannot be used as substitutes for hip replacement surgery,but they are helpful in managing pain before and after the operation, and in speeding physical recovery. Many patients also find that CAM therapies help them maintain a positive mental attitude in coping with the emotional stress of surgery and physical therapy. CAM therapies that have been shown to relieve the pain of rheumatoid and osteoarthritis include acupuncture, music therapy, naturopathic treatment, homeopathy, Ayurvedic medicine, and certain herbal preparations.

Chronic pain from other disorders affecting the hip has been successfully treated with biofeedback, relaxation techniques, chiropractic manipulation, and mindfulness meditation. Some types of movement therapy are recommended in order to postpone the need for hip surgery. Yoga, tai chi, qigong, and dance therapy help to maintain strength and flexibility in the hip joint, and to slow down the deterioration of cartilage and muscle tissue. Exercise in general has been shown to reduce a person’s risk of developing osteoporosis.

Alternative surgical procedures
Other surgical options include:
• Osteotomy. An osteotomy is a procedure in which the surgeon cuts the thigh bone or pelvis in order to realign the hip. It is done more frequently in Europe than in the United States, but it has the advantage of not requiring artificial materials.

• Arthrodesis. This type of operation is rarely performed except in younger patients with injury to one hip. In this procedure, the head of the femur is fused to the acetabulum with a plate and screws. The major advantage of arthrodesis is that it places fewer restrictions on the patient’s activity level than a hip replacement.

• Pseudarthrosis. In this procedure the head of the femur is removed without any replacement, resulting in a shorter leg on the affected side. It is usually performed when the patient’s bones are too weak for implanting a prosthesis or when the hip joint is badly infected. This procedure is sometimes called a Girdlestone operation, after the surgeon who first used it in the 1940s.