August 12, 2005

Leg strength before knee surgery predicts results

By Anthony J. Brown, MD

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

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.