An emphasis on innovative, lesser-invasive surgical techniques for knee and hip replacement and the use of technologically advanced prostheses defines Cedars-Sinai Medical Centre as a pioneer in the field of joint replacement, says Andrew Spitzer, MD, associate director of the Institute for Joint Replacement. Patients whose surgery is performed at Cedars-Sinai using lesser-invasive surgical techniques are often is charged from the hospital within three days after surgery and are back to normal functioning within one to two months. The goal of lesser-invasive, minimum-incision surgery for knee and hip replacements, says Spitzer, is to try to facilitate the patient rehabilitation.
“Lesser invasive joint replacement is valuable to the extent that it shortens the window between when the surgeon finishes the operation and the time the patient is able to mobilise and get back into an active, productive lifestyle. Shrinking the rehabilitation period-from three to six months to one to two months-is a very enticing goal both from the healthcare industry’s viewpoint of resource management and economics and from the patient’s viewpoint of more quickly returning to the workplace and being able to remain active there for a longer period of time.” One of the lesser-invasive techniques Spitzer uses in hip replacement surgery is a short posterior incision which minimises the dissection of muscle and reduces the damage to surrounding tissues.”This approach has facilitated a more rapid recovery and discharge for our patients on an anecdotal basis. We haven’t scientifically looked at the data yet but we feel that this smaller incision technique, combined with the greater attention to soft tissue and more careful surgical techniques, seems to result in a quicker rehabilitation period for the patient,” Spitzer said.He emphasises that it’s important to note that other changes have been made in the arena of lesser invasive joint surgery as well, such as more aggressive pain management programs and improved patient education. Nurses are helping patients to become mobile more quickly after surgery and patients are becoming empowered to take charge of their rehabilitation and become independent as quickly as possible.”Ten years ago we had patients staying in the hospital for one to two weeks after their joint replacement surgery (both knee and hip) and now we’ve reduced that to one to three days in some cases,” says Spitzer. As the baby boomer generation ages, the number of hip replacement surgeries is expected to increase. In 2001, about 165,000 hip joints were replaced in U.S. hospitals according to the National Centre for Health Statistics, and 326,000 knees were replaced. While the majority of joint replacement patients remain in the 60-plus year category, more people are deciding to have surgery one or two decades earlier, some-like rock star Eddie Van Halen- in their early 40s. A hip or knee replacement lasts at least 20 years in about 80 per cent of those who receive them, according to the U.S. Food and Drug Administration.About 70 per cent of people seeking hip replacement surgery have severe osteoarthritis, a common chronic disease that damages cartilage, the tissue that acts as a protective cushion allowing for the smooth, low-friction movement of the joint. Osteoarthritis is the leading cause of long-term knee damage and the most common reason for knee replacement. By age 65, women are five times more likely than men to have this disease.One of the newer hip prostheses Spitzer uses is a triple-tapered polished collarless stemreplacement, a technology he helped to design. “This cemented prosthesis represents an interesting twist in the history of hip replacements. Its unique feature is that it is the only prosthesis in its particular variety that has been observed to actively create positive remodeling of the bone.”Over time, he explains, prostheses tend to cause the bone around them to waste in such a way that the body doesn’t load them properly. Eventually, the bone surrounding the replaced joint becomes weaker and thinner and can fail catastrophically. “There is some early evidence to indicate that this new type of prosthesis may be causing the bone to positively remodel or reinforce itself in a physical manner.””Cemented stems, paradoxically, have been felt to be more applicable to an older population. This particular prosthesis may create an indication for use in younger patients, particularly in those who may otherwise be looking at multiple joint replacements during their lifetime.”Another technically advanced implant being used at Cedars-Sinai is mobile-bearing kneereplacement prosthesis. “The mobile-bearing prosthesis is a different concept than the more traditional fixed-bearing knee replacement. The plastic that’s between the two metal pieces actually moves in multiple planes. The benefit of this kind of prosthesis is that it changes the knee prosthesis from something closer to a hinge-type function to a more natural function. This allows for a reduction in the wear associated with knee replacements by as much as 95 per cent. Since the wearing surface has been one of the weaker links in the replacement process, we’re looking at expanding the longevity and durability of these surgeries, thereby greatly reducing the need for revision surgery.”(Source: Cedars-Sinai Medical Centre: August 2006).