Exercise after knee replacement is critical to recovery, according to study

Quadriceps exercises are critical to recovery in patients who received a knee replacement as a treatment for osteoarthritis, according to a University of Delaware study published in the February issue of Arthritis Care & Research.

In a randomized controlled trial at the University of Delaware’s Physical Therapy Clinic conducted between 2000 and 2005, 200 patients who had undergone knee replacements were given 6 weeks of progressive strength training two or three times a week, starting 4 weeks after surgery. Half of the group also received neuromuscular electrical stimulation, according to a press release.

The researchers compared those patients’ function to that of 41 patients who received conventional rehabilitation and home physical therapy. Quadriceps strength, knee range of motion and gait were measured in such tests as timed up-and-go, stair climbing and a 6-minute walk.

Patients participating in the progressive strength-training program showed significant improvement in quadriceps strength and functional performance. They also demonstrated substantially greater quadriceps strength and functional performance after 12 months than the group that underwent conventional rehabilitation.

“It sounds logical that exercises to strengthen your knee should be a component of your post-operative physical therapy after a total knee replacement, but it’s not the convention at all,” Lynn Snyder-Mackler, PhD, researcher and Alumni Distinguished Professor of Physical Therapy at the University of Delaware, said in the press release. “Our study demonstrates that intensive strength exercise as outpatient therapy is critical to begin 3 to 4 weeks after surgery.”

Reference:
Petterson SC, Mizner RL, Stevens JE, et al. Improved function from progressive strengthening interventions after total knee arthroplasty: A randomized clinical trial with an imbedded prospective cohort. Arthrit Care Res. 2009; 61(2):174-183.