April 27, 2000 -- Despite the increasing number of total knee replacements being performed in the U.S., few studies have looked at which sports activities are best -- and which are best avoided -- after surgery. But, after measuring the stress load placed on knee replacements, Swiss researchers have determined which activities are safest and which can be harmful.
"Patients should alternate activities such as power walking and cycling, which place less stress and pressure on the knee, and they should avoid high-stress endurance sports such as jogging and sports involving running," lead author Markus S. Kuster, MD, PhD, tells WebMD. Kuster is an orthopaedic surgeon at the Clinik Für Orthopädische Chirurgie, Kantonsspital, in Gallen, Switzerland.
Kuster also advises staying away from downhill mountain hiking or "at least using ski poles and avoiding heavy backpacks." Mountain hiking involves ascending and descending steep trails, and walking uphill has been shown to produce minimal force on the knee. But, when Kuster and his researchers recorded the stress placed on knees during downhill walking, they found it to be quite high. For downhill hikes after total knee replacement surgery, they suggest walking slowly to reduce the burden on the knee joint. Their research was published in the April issue of Medicine & Science in Sports & Exercise.
According to experts, one of the reasons that more knee replacements are being performed today than ever before is that physicians have found it's much better to intervene early rather than late. "In the past, the doctor typically would not operate until the person had a foot in the grave," Jerry L. Cochran, MD, FACS, tells WebMD.
By waiting, he says, "people would get out of shape, lose muscle tone and cardiovascular endurance, and gain weight. We don't want that to happen because it brings on aging and loss of motion. We know today that it's better to do the joint replacement early to keep the person active. A person should not trade their health for time." Cochran is director of the Midland (Texas) Orthopaedic Clinic and was not involved in the study.
"Usually, when a patient gets a total joint replacement, they think, 'Now I'm an old person.' But if a joint is put in appropriately, it will be like taking 20 years off your age," he says. "You will be able to do the things you enjoy again, and that's very important because it reconfirms our existence as a human being -- it's good for our psyche." Cochran speaks from experience; he recently underwent a successful joint replacement himself.
Kuster agrees that patients should remain active for overall general health. "If patients want to perform endurance sports after total knee replacement, they should alternate power walking and cycling and [avoid activities] like stepping," he says.
"This is good news for the patient," Patrick Meere, MD, tells WebMD. "[Researchers] are now in the final stages of perfecting the [total knee replacement,] and we're offering it to younger patients." The downside, Meere says, is that "joint replacements offering greater range of motion may result in patients placing too much wear and tear on the mechanisms. Patients should be reassured that [walking and cycling] are very important after total knee replacement, but contact sports should be banned forever." Meere is a clinical assistant professor of orthopaedic surgery at NYU Hospital for Joint Diseases in New York.
Cochran's advice to prevent the need for hip or knee replacement is to "avoid the extremes of any sport. Hips and knees were meant to bend, but don't overdo it."