Knee Replacement Surgery Is 'Durable, Reliable, and Successful'
WebMD News Archive
Feb. 7, 2000 (New York) -- In recent years, orthopaedic surgeons have made
tremendous strides in total knee replacement surgery or total knee arthroplasty
for people with severe arthritis of the knee.
And that's good news, because more than 245,000 total knee replacements are
performed in the U.S. annually, and this number is expected to increase as the
percentage of Americans over 65 years of age rises in the coming years, write
study authors Peter J. Thadani, MD, and Andrew I. Spitzer, MD, of the
Kerlan-Jobe Orthopaedic Clinic in Los Angeles, in the January issue of the
Current Opinion in Orthopedics.
In knee arthritis, the cartilage in the joint gradually wears away,
resulting in pain, swelling, and a decrease in motion. First developed in 1974,
knee replacement surgery has undergone many technical improvements and is now
an "accepted, reliable form of treatment of the end-stage arthritic
knee." The procedure basically involves removing or resurfacing parts of
the kneecap and putting in an implant made, usually, of metal alloy and
plastic. The ends of the bone are capped with a metal substance and a plastic
liner is placed between them to create a smooth gliding surface, and presumably
"The take-home message is that your own God-given knee is the best.
However, as the knee wears and the arthritis becomes severe and unresponsive to
pain killers and other nonsurgical treatments, knee replacement is a very
viable, reliable, and durable option," Spitzer tells WebMD.
"Implants are not made for running, jumping and other high-impact
activities, but they can enable you to participate in a whole host of other
activities," he says. "While current implants can last from 12 to 25
years, implants may last as long as 20-30 years in the next
After reviewing published data on available knee replacement implants and
surgeries, Spitzer and Thadani conclude that many of the new implants and
surgical procedures are "durable, reliable, and successful over the long
term." Most procedures evolved from total condylar knee prosthesis, a
surgery which involved sacrificing the posterior cruciate ligament (PCL), a
ligament found behind the knee, and uses cement to hold the new implant in
place. The majority of newer surgical innovations involve salvaging the
ligaments surrounding the knees, Spitzer says.
In terms of available implants, "in straightforward cases, the choice of
one design over another is largely a matter of surgeon preference," they
After reviewing several studies on the outcomes of knee replacements, the
authors find "excellent long-term success" with most of the studies
showing well over 90% survivorship at periods ranging from 10 to 16 years and
annual failure rates significantly under 1%.
Newer implants include "cementless" implants, which show promising
results and may become particularly beneficial for younger patients. A lot of
research is now being directed at improving these implants for younger, more
active patients, the authors report.