Leg Strength Before Knee Surgery Predicts Results

NEW YORK (Reuters Health) - For patients undergoing total knee replacement, the strength of their quadriceps muscles before surgery is a good predictor of how well they'll be functioning a year later, study results indicate.

Quadriceps are the large muscles on the front of the thigh. The findings suggest that the quadriceps strength should be optimized with physical therapy or other measures before knee replacement is performed, Dr. Lynn Snyder-Mackler, from the University of Delaware in Newark, told Reuters Health.

Another message is that "maybe we shouldn't wait forever to do the surgery" -- that is to say, perhaps knee replacement performed earlier when patients are more functional and haven't lost a lot of strength.

People who undergo knee replacement typically "trade joint deformity and pain before the operation for weakness afterward," Snyder-Mackler noted. "In this paper, we tried to focus on things that you could change before surgery to improve patients' function afterward."

The study, published in the Journal of Rheumatology, involved 40 patients who were evaluated with various strength and functional measures before and 1 year after total knee replacement.

In terms of functional outcomes, the operation led to significant improvements in the two main measures, the Timed Up and Go test and the Stair Climbing test. Further analysis showed that pre-operative quadriceps strength was directly related to the degree of improvement on both these tests.

The results highlight the need for interventions to improve quadriceps strength in candidates for total knee replacement, the team notes.

SOURCE: Journal of Rheumatology, August 2005.