SUNDAY, Sept. 12, 2004 (HealthDayNews) -- Every year in the United States, more than 325,000 aching knees need to be replaced as the joints deteriorate.
But for those facing such surgery, there's some encouraging news: A small but growing number of surgeons have been performing what they call "minimally invasive total knee replacements." Because the procedure involves a smaller incision and is less complicated, the time spent hospitalized is reduced and recovery is faster.
It's akin to the minimally invasive techniques surgeons have been using for hip replacements in recent years.
Some doctors caution that not everyone is a candidate for the knee procedure, and some worry it doesn't have a long enough track record to justify it as the better technique.
For those in need of new knees, experts recommend they question their orthopedic surgeon thoroughly and educate themselves about the new procedure -- and the traditional one -- before having surgery.
Dr. Richard Berger, an assistant professor of orthopedic surgery at Rush Presbyterian Medical Center in Chicago, is a pioneer of the new technique. He predicts that five years from now, almost all surgeons will be performing the minimally invasive procedure. "There's really no downside, only an upside," he said.
Berger estimates that only about 3 percent of orthopedic surgeons in the United States are currently doing the minimally invasive knee procedure. But as more complete the necessary training, they'll jump on the bandwagon, he said.
"At some point almost every orthopedic surgeon is going to be doing this surgery," he said.
In traditional knee-replacement surgery, Berger explained, the length of the incision varies, typically between 8 inches to 10 inches. "The quadriceps (front of the thigh) muscle is cut or split, the kneecap is flipped over and that exposes the knee. The bone is cut and sized, and the [artificial] knee replacement is put in."
With the new technique, "we make an incision that is 3.5 inches or so," Berger said. "We don't cut muscle. We take out the bad bone and cartilage but without cutting any of the muscle or tendon." Then the prosthetic replacement is put in place.
People who need knee replacement typically experience significant pain that can worsen as the cartilage that cushions the joint deteriorates. While pain medications and walking aids, such as a cane, may help temporarily, the only long-term solution is usually replacement.
The traditional approach requires 12 to 14 weeks of physical therapy, Berger said. With the new approach, patients are often walking with a cane and even driving within about 12 days, says another pioneer, Dr. Peter Bonutti, a fellow of the American Academy of Orthopaedic Surgeons.
Another big plus with the minimally invasive technique is the reduction in post-operative pain, according to proponents.
The key to the operation -- besides the doctor's skill -- is the development of new surgical instruments, said Bonutti. "What we developed are new, smaller instruments, to allow us to accurately position the joints without having to dislocate the knee cap to perform the procedure."
Added Berger, "We get the knee moving more rapidly because it doesn't hurt as much."
The hospitalization time with traditional surgery is about four days, Berger said. He said he does the new surgery on an outpatient basis, but other doctors admit their patients to a hospital for the operation.
Even advocates such as Bonutti and Berger acknowledge that not everyone is a candidate for the surgery. People who have already had extensive surgery on their knee may not be good choices, said Berger. "And those who are morbidly obese may not be," he said.
But for most patients, the new approach represents a breakthough, Berger said. Both he and Bonutti agreed, however, that it's crucial to find a surgeon who has performed the new technique enough to be proficient at it.
Several companies are now making the instruments for the new surgery, and more doctors are training in the technique. A surgeon who has done 30 to 50 such operations would probably have a sufficient level of experience, Bonutti said.
More information
To learn more about minimally invasive knee replacement surgery, visit the American Academy of Orthopaedic Surgeons.
