By Pat Anson, Editor

New research is raising questions about the value of knee replacement surgeries, one of the fastest growing elective procedures in the United States.

In an analysis of over 7,400 patients with osteoarthritis who had knee replacement surgeries, researchers concluded the procedure often had minimal effects on quality of life and wasn’t worth the cost. But when the surgeries are performed on patients with more severe knee pain, their effectiveness increases, researchers reported in The BMJ.

The annual rate of total knee replacements in the U.S. has doubled since 2000, with more than 640,000 surgeries now performed annually at a cost of $10.2 billion.

"Given its limited effectiveness in individuals with less severely affected physical function, performance of total knee replacement in these patients seems to be economically unjustifiable," wrote lead author Bart Ferket, MD, an assistant professor at the Icahn School of Medicine at Mount Sinai in New York City.

"Considerable cost savings could be made by limiting eligibility to patients with more symptomatic knee osteoarthritis,"

Osteoarthritis is a joint disorder that leads to thinning of cartilage and progressive joint damage. Nearly 40 percent of Americans over the age of 45 have some degree of knee osteoarthritis, and those numbers are expected to grow as the population ages.

Ferket and his colleagues found that about a third of the patients who had their knees replaced continued to experience chronic pain after the procedure. Their quality of life generally improved, but the change was small. The improvement in quality of life was higher when patients with lower physical scores before surgery were operated on.

“The practice of total knee replacement as performed in a recent U.S. cohort of patients with knee osteoarthritis had minimal effects on quality of life. If the procedure were restricted to patients with more severe functional status, however, its effectiveness would rise, with practice becoming economically more attractive,” they concluded.

"Our findings emphasize the need for more research comparing total knee replacement with less expensive, more conservative interventions, particularly in patients with less severe symptoms.”

Previous studies have also questioned the value of many knee surgeries. A five year study of 175 knee replacement patients by the National Institutes of Health found that over a third of the surgeries were inappropriate. Many patients had pain and other symptoms that were too mild to justify having their knees replaced.  

Another study found that arthroscopic knee surgery is “not an economically attractive treatment option” compared to physical therapy, exercise and medication.

In arthroscopic surgery, a doctor makes a small incision in the knee and inserts a tiny camera and instruments to repair damaged ligaments or torn meniscus. Arthroscopic surgery is far less invasive than a total knee replacement. Depending on insurance, hospital charges and the surgeon, arthroscopic surgeries cost about $4,000.  A total knee replacement costs about $28,000 according to HealthCare Bluebook.