New & Improved

Do you long for knees that do what you tell them to do, with no argument? Was a pain-free hip on your Christmas list? For your grandparents, such wishes were just that … wishes. Today these wishes can come true. Modern joint replacement surgery has given thousands of people the pain free, active lives they feared were lost forever.

Dr. Douglas Joseph, an orthopedic surgeon affiliated with St. Joseph Hospital in Nashua, explains improvements that have made this possible. The variety of materials that can be used is a major change. These include stainless steel, cobalt, titanium, ceramic and polymers. He gives an example of a hip replacement using a titanium stem, a stainless-steel ball or head and a cup made of titanium backed with a polyethylene plastic liner.

The replacement part may be cemented in place or the surgeon may use a part with a porous surface next to the bone. In time the bone grows into the metal, making a natural bond. These new materials are designed to last a lifetime.

Minimally invasive surgery is a major improvement in total joint replacement. The length of the incision will vary somewhat, but will be about half the length of standard practice several years ago. For example, an incision for hip replacement that once would have been 10 inches will now be five. This reduces muscle damage, produces less bleeding and presents fewer complications with healing.

Replacement parts — the stem in the hip joint, for example — once were standard in design. Now there are many designs. Another new approach takes into account the anatomical differences between men and women in knee structure. In 2006, the Zimmer Corporation, a national leader in joint replacement surgery, brought the “gender knee” to the market. It is designed for women and, says Dr. Joseph, is thinner, narrower and matches the anatomy of the female knee. There is no loss of sturdiness and speed of recovery is improved.

The long-term survival rate for replacement parts is 80 percent in hip replacement and 95 percent in knee replacement. The old fear of having to face another surgery in a few years to replace the now-worn replacement parts is seldom a factor.

Dr. Eric Benson, an orthopedic surgeon affiliated with Elliot Hospital and Catholic Medical Center, says that there has been a huge increase in joint replacement over the past few years. In 2005, there were 350,000 knee replacements and 250,000 hip replacements in this country.

“Joint replacement surgery began in the 1960s,” he explains. “We will soon have a 50-year assessment. We know what we are doing.” He notes the improvement in materials, design and technique. More sophisticated and individualized anesthesia and better pain management have also improved success rates and patient satisfaction, he says. Problems in the early post-operative period are possible, but extremely rare.

Age is no longer a factor, Dr. Benson says. The median age for hip replacement is 62 but there are many patients on either side of that age. Given the long life of the replacement parts, patients in their 50s may never need revision (new parts). Healthy people in their 70s, 80s and even 90s will also benefit from the surgery. Pain is eliminated. Joint replacement often means the difference between independence and dependence on others for basic tasks.

Dr. Benson describes a new technique used in total knee replacement. An MRI of the knee is taken. The images are converted into two 3-dimensional plastic “cutting blocks.” A block is placed on end of the femur; there are slots for the precise locations of the bone cuts to be made.

Hip joint resurfacing has attracted attention, especially as an option for younger people who want to delay total replacement. Several millimeters of diseased bone are removed from the head of the femur, then cemented with a metal cap and placed into a metal-lined socket. The head and neck of the femur are preserved. In theory at least, the hip is less debilitated when a total replacement is needed in later years. “This procedure is not less invasive,” says Dr. Benson, “and has a higher failure rate than total hip replacement. I suggest great caution in choosing this option.”

Recovery and Rehabilitation: Total joint replacement usually involves a three-day hospital stay, followed by discharge to home, with in-home nursing and therapy services. Older patients or those without family support may go directly to a rehab center for a few days. By about one month post operation, patients begin outpatient rehabilitation. This is critical to restore strength and range of motion. Most will be back to normal activities in two months. Dr. Benson does tell his patients to avoid high impact sports, such as running or contact sports. “But some do resume even these,” he says.

Other joints, including knuckles, elbows and shoulders, can be replaced. Ankle replacement is possible, but difficult and rare. Hip and knee replacements far outnumber other procedures.

Prevention and Alternative Treatment: With few exceptions, the primary cause of joint problems is arthritis, both osteo and rheumatoid. There are a few things one can do that may help to prevent advanced osteoarthritis. Weight control is the most important factor. The correlation between excess weight and knee problems is high. Regular exercise is also needed to keep the joints flexible and lubricated. Unfortunately, excess weight often leads to inactivity. Certain occupations may predispose a person to arthritis, specifically those that require repetitive and/or high impact movement.

Anti-inflammatory medicines ease the pain but do not cure the arthritis. Corticosteroid injections in the hip may be used for greater pain relief. Massage, warmth and other soothing techniques can help one to feel better, but have no long-term benefits. Chondroitan and glucosamine may have some modest restorative benefit.

“Hospitals across New Hampshire provide outstanding orthopedic care,” concludes Dr. Joseph. “The team in the operating room at St. Joseph’s includes experienced surgeons, surgical nurses and orthopedic technicians. There is no need to go to Boston.”

“Total hip replacement rates high on the insurance industry’s quality of life scale,” says Dr. Benson. “The failure rate is under 2 percent. Pain is relieved and one’s regular activities can be resumed. From the working person who can continue employment to the elder who avoids going to a nursing home, the surgery is certainly cost effective.” NH