As the country’s population ages, the number of total hip replacements performed in the United States will increase drastically in the next 25 years. Total hip replacement has proven to be an effective operation that helps

patients with arthritis of the hip regain nearly normal function, allowing them to return to almost all activities.

Hip replacement technology was developed in the 1960s by British orthopedic surgeon Sir John Charnley. Prior to hip replacement, fusion of the hip was the only way to alleviate the pain of an arthritic hip. This left patients with a stiff hip that restricted many activities.

Hip replacement involves replacing the ball-and-socket hip joint. The ball is the upper end of the femur, or thighbone, which sits and moves in the socket that is part of the pelvic bone. Due to wear or trauma, the ball-and-socket joint becomes painful as the normal joint lining deteriorates.

There are many different materials used for hip replacement; the age of the patient and the surgeon’s preference will usually determine the best option for a given individual. The most popular is a ball of cobalt chromium or titanium metal and a polyethylene cup backed by a metal shell; however, other materials such as ceramic or metals are also used. The majority of total hips today are not cemented in place, but rather press-fit. This allows bone to grow into a rough surface on the new hip joint, fixing it without cement. Subsequently, there is a lower incidence of loosening of the hip, one of the problems seen after hip replacement surgery.

The operation is performed through a 4- to 6-inch incision on the side of the hip joint. It takes about an hour to an hour-and-a-half to complete the surgery, and patients begin physical therapy either the day of or the day after the replacement operation. Physical therapy involves walking with a walker or crutches, and exercising the muscles around the hip joint. It takes three to six months to regain normal function and strength.

Approximately 95 percent of patients who undergo total hip replacement are satisfied with the results. Those who do not do well may have one of the major complications: infection, which occurs in 1 to 2 percent of the hips done; dislocation of the hip; or injury to the sciatic nerve. The replacement can last a long time, with 80 percent of hip replacements lasting at least 15 years.

Although there are many reasons people need total hip replacement, osteoarthritis is the main cause. Heredity appears to play a role, with some patients developing hip osteoarthritis as early as their 30s or 40s. Obesity is also a factor because of the increased pressure placed on this weight-bearing joint. Trauma such as fracture or dislocation can also cause the hip to fail. High doses of several medications, such as steroids, can also cause conditions that destroy the hip joint.

One of the most commonly asked questions from patients is when to undergo the procedure. The ideal time is whenever they experience pain and disability that keeps them from living the life they want to live.

– Dr. John Benner is an orthopedic surgeon with the Chetser County Hospital and Health System.