Which Knees Need the Knife?

Osteoarthritis with a meniscal tear best treated with surgery and physical therapy

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) A burning question among orthopedic docs is when is it appropriate to operate versus when to wait and prescribe physical therapy? In short, who needs the knife?

A recent study found similar outcomes for osteoarthritis patients treated with surgery plus physical therapy versus physical therapy alone.

However, some patients who just had physical therapy ended up requiring knee surgery. 

"Learn about physical therapy before surgery."

Jeffery Katz, MD, of Orthopedic and Arthritis Center for Outcomes Research Brigham and Women's Hospital, Boston, and colleagues led the study to determine if patients with a meniscal tear and knee osteoarthritis had better outcomes with surgery plus physical therapy or just physical therapy. 

Meniscal tears are common knee injuries, observed in 35% of people older than age 50. The meniscus is a rubbery, C-shaped disc that cushions the knee. Tears are often treated with arthroscopic partial meniscectomy, which is a surgical procedure to trim or repair the torn meniscus. 

Osteoarthritis occurs when the cartilage that protects the bones begins to wear away. Osteoarthritis can be very painful and puts patients at risk for injuries. 

The study had 351 patients randomly assigned to receive either surgery plus physical therapy, or physical therapy with an option to have surgery if later needed. 

Researchers used the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index to measure patients' physical functioning after six and 12 months. The WOMAC index is a 1- to 100-point scale that measures the physical functioning of the knee. 

Results showed that patients who had surgery plus physical therapy had an overall 20.9 point improvement in their WOMAC score, compared to 18.5 points in the physical therapy group. 

While there was not a significant difference in physical functioning between the groups, some of the physical therapy only patients eventually needed knee surgery. 

At six months, 30 percent of the physical therapy group had knee surgery. At 12 months, 35 percent of the physical therapy group had knee surgery. 

Researchers also looked at how many patients had an improved WOMAC score of at least 8 points. In the surgery plus physical therapy group, 67 percent of patients had an 8 point improvement versus 44 percent of the physical therapy group. 

There were some limitations to the study. About 25 percent of eligible patients enrolled in the study mostly because they wanted a specific treatment. Also, patients were enrolled from an academic referral center not a community medical setting. The results may not be generalizable. 

This study, titled "Surgery versus Physical Therapy for a Meniscal Tear and Osteoarthritis," was published in The New England Journal of Medicine. It was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health. Some of the authors disclosed receiving consulting fees from companies selling orthopedic devices and pharmaceutical companies.

Reviewed by: 
Review Date: 
March 21, 2013
Last Updated:
March 25, 2013