Total hip replacement is a common procedure. It involves removing the head of the thighbone (femur). The ball-and-socket mechanism of the hip is replaced with artificial implants.

As the population ages over the next decade, this procedure is expected to become even more common. Patients who undergo hip replacement are typically 60 to 75 years old. More than 90 percent of hip replacements last for 10 years or more. Pain and mobility improve after hip replacement. This allows patients to maintain their independence and quality of life.

Newer techniques and implants have been developed. They make hip replacement a less invasive operation. It takes less time for the patient to recover from surgery. The new implants are engineered to last longer.

» Treatment Options: Surgical

Even when you get all of the right nonsurgical treatments, problems with pain and mobility sometimes get worse. In this case, the doctor may recommend surgery. Surgical options include:

Arthroscopy: Arthroscopy of the hip is a minimally invasive, outpatient procedure. It is relatively uncommon. The doctor may recommend it if the joint has evidence of torn cartilage or loose fragments of bone or cartilage.

Osteotomy: Candidates for osteotomy include younger patients with early arthritis, particularly those with abnormally shallow hip socket (dysplasia). The procedure involves cutting and realigning the bones of the hip socket and/or thighbone. This creates a more normal relationship between the ball and socket. It decreases pressure in the joint. In some cases, this may delay the need for replacement surgery for 10 to 20 years.
Traditional Hip Replacement: The doctor may recommend hip replacement when all of the above measures have been considered or have been tried and failed. Traditional hip replacement surgery involves making a 10-inch to 12-inch incision on the side of the hip. The muscles are split or detached from the hip. The hip is dislocated. The ball of the femur is removed. The hip socket is prepared by removing any remaining cartilage and some of the surrounding bone. The cup implant is pressed into the bone of the socket. It may be secured with screws. A bearing surface is inserted into the socket.

Next, the femur is prepared by removing some bone from the inside of the thighbone. A metal stem is placed into the thighbone to a depth of about 6 inches. The stem implant is either fixed with bone cement or is implanted without cement. Cementless implants have a rough, porous surface. It allows bone to adhere to the implant to hold it in place. A ball is then placed on the top of the stem. The ball-and-socket joint is recreated.

Minimal Incision Hip Replacement: Minimal incision hip replacement surgery lets the surgeon perform hip replacement through one or two smaller incisions. Compared with most people getting hip replacements, candidates for minimal incision procedures are typically thinner, younger, healthier and more motivated to have a quick recovery. Before you decide to have a minimally invasive hip replacement, get a thorough evaluation from the operating surgeon. Discuss with him or her about the risks and benefits. Both traditional and minimally invasive hip replacement procedures are technically demanding. They require that the surgeon and operating team have considerable experience.

The artificial implants used for the minimally invasive hip replacement procedures are the same as those used for traditional hip replacement. Specially designed instruments are needed to prepare the socket and femur and to place the implants properly. The artificial hip is implanted in the same way. But there is less soft-tissue dissection than with longer incisions.

A single minimally invasive hip incision may measure only 3-inches to 6-inches. It depends on the size of the patient and the difficulty of the procedure. The incision is usually placed over the outside of the hip. The muscles and tendons are split or detached, but to a lesser extent than in the traditional hip replacement operation. They are routinely repaired after the surgeon places the implants. This helps healing. It helps prevent dislocation of the hip.

Reported benefits of less invasive hip replacement include:

• Less pain
• More cosmetic incisions
• Less muscle damage
• Rehabilitation is faster
• Hospital stays are shorter--For traditional hip replacement, hospital stays average four to five days. Many patients need extensive rehabilitation afterward. With less invasive procedures, the hospital stay may be as short as one or two days. Some patients can go home the day of surgery.

Early studies suggest that minimally invasive hip replacement surgery streamlines the recovery process. But the risks and long-term benefits of the less invasive techniques have not yet been documented to represent an improvement over traditional hip replacement surgery.

» What's New?

Extensive study and development are now underway to determine the long-term benefits of minimally invasive hip replacement. New technology for imaging and computer-assisted implant placement has been developed. It continues to be modified as experience with smaller incision surgery grows. This will allow more precise reconstruction of the hip with less direct visualization. In addition, new implant designs and materials are being developed to both facilitate minimally invasive surgery on the hip and to prolong the lifespan of replacements.