‘Common knee surgery does very little for some’

The unusual study involved people with a torn meniscus,crescent-shaped cartilage that helps cushion and stabilize knees. Arthroscopic surgery on the meniscus is the most common orthopaedic procedure in the United States,performed,the study said,about 700,000 times a year at an estimated cost of $4 billion.

The study,conducted in Finland,involved a small subset of meniscal tears. But experts,including some orthopaedic surgeons,said the study added to other recent research suggesting that meniscal surgery should be aimed at a narrower group of patients; that for many,options like physical therapy may be as good.

The surgery,arthroscopic partial meniscectomy,involves small incisions. They are to accommodate the arthroscope,which allows doctors to see inside,and for tools to trim torn meniscus and to smooth ragged edges of what remains.

The Finnish study does not indicate that surgery never helps; there is consensus that it should be performed in some circumstances,especially for younger patients and for tears from acute sports injuries. But about 80 percent of tears develop from wear and ageing,and some researchers believe surgery in those cases should be significantly limited.

“Those who do research have been gradually showing that this popular operation is not of very much value,” said Dr David Felson,a professor of medicine and epidemiology at Boston University. This study “provides information beautifully about whether the surgery that the orthopaedist thinks he or she is doing is accomplishing anything. I think often the answer is no.”

The volunteer patients in the Finnish study all received anesthesia and incisions. But some received actual surgery,others simulated procedures. They did not know which.

A year later,most patients in both groups said their knees felt better,and the vast majority said they would choose the same method again,even if it was fake.

“It’s a well-done study,” said Dr David Jevsevar,chairman of the committee on evidence-based quality and value of the American Academy of Orthopaedic Surgeons. “It gives further credence or support to a number of studies that have shown that giving arthroscopy to patients is not always going to make a difference.” Dr Jevsevar,an orthopaedic surgeon in St George,Utah,said he hoped the study would spur research to better identify patients who should have surgery.

“Are there operations that are done that do not need to be done? I’m sure that’s the case,but we don’t know the magnitude,” he said. “We still think there’s benefit in arthroscopic meniscectomy in appropriate patients. What we need to define in the future is what’s the definition of appropriate patient.”

One factor is whether pain is caused by the torn meniscus or something else,especially osteoarthritis,which often accompanies tears. Another possible consideration is whether mechanical knee function is affected.

The new research builds on a groundbreaking 2002 Texas study,showing that patients receiving arthroscopy for knee osteoarthritis fared no better than those receiving sham surgery. A 2008 Canadian study found that patients undergoing surgery for knee arthritis did no better than those having physical therapy and taking medication. Now many surgeons have stopped operating on patients with only knee arthritis.