Study finds decreased muscle strength 4 years post-meniscectomy

Patients with greater quadriceps muscle strength on the treated leg had significantly less pain, better function and better quality of life.

Patients can experience decreased leg muscle strength and function 4 years after undergoing meniscectomy for nontraumatic meniscal tears, according to a study by researchers in Sweden.

Ylva B. Ericsson, PT, MSc, and colleagues at Malmö University Hospital and Lund University evaluated muscle strength, performance and subjective outcomes at an average of 4 years after meniscectomy. The study included 45 patients with an average age of 46.7 years at the time of the study (range, 38 to 50 years). All patients had undergone arthroscopic partial meniscectomy to treat nontraumatic meniscal tears 1 year to 6 years before study initiation.

To assess muscle strength, investigators evaluated the isokinetic strength of patients' knee extensors and flexors. Functional performance was evaluated using the one-leg hop test, one-leg rising test and the square-hop test. Researchers also subjectively evaluated function using the Knee Injury and Osteoarthritis Outcome Score (KOOS), which measures pain, function in daily activities and sports, and knee-related quality of life.

The researchers found that knee extensor strength was significantly worse for meniscectomy-treated legs compared to legs that did not undergo surgery when performing the one-leg rising test (P<.004). However, no significant differences were noted between treated and nontreated legs in terms of knee flexor strength (P>.3), according to the study.

The researchers also found that quadriceps muscle strength corresponded to KOOS scores; patients with greater quadriceps muscle strength on the treated leg had significantly less pain, better function and better quality of life (P<.01).

Previous studies have shown reduced muscle strength a few months after surgery, but little emphasis has been on restoring strength. The current study shows that decreased muscle strength and performance can remain up to 4 years after meniscectomy, according to a press release announcing the study results.

"Meniscectomy patients are usually prescribed a home exercise program, but supervised physical therapy is not considered necessary," the authors said in the release.

"In the present study, the association between the quadriceps strength deficits and self-reported symptoms and function suggests a close relationship between muscle strength and functional limitations in middle-aged patients who have undergone meniscectomy," the authors said. The findings suggest that decreased quadriceps strength may contribute to limited knee function, they added.

"This relative quadriceps weakness significantly affects objective and self-reported knee function, pain and quality of life, indicating the importance of restoring muscle function after meniscectomy in middle-aged patients," the authors said.

For more information:
Ericsson YB, Roos EM, Dahlberg L. Muscle strength, functional performance, and self-reported outcomes four years after arthroscopic partial meniscectomy in middle-aged patients. Arthritis Care & Research. 2006;55:946-952.