Common Knee Surgery Should Probably Be a Last Resort

Knee problems are a common marker of aging, and knee surgery to fix them is equally common. According to a recent study published in the New England Journal of Medicine (NEJM), you have to wonder why.

As summarized in the New York Times, “A popular surgical procedure worked no better than fake operations in helping people with one type of common knee problem, suggesting that thousands of people may be undergoing unnecessary surgery, …”

Arthroscopic repair of torn meniscus, which is the cartilage in the knee joint that keeps the bones from grinding on each other and serves as a stabilizer, is the most common orthopedic procedure in the U.S., according to the study; about 700,000 such operations are performed every year at a cost of about $4 billion.

Arthroscopy is used by orthopedic doctors to diagnose and sometimes treat disorders of the bones and joints, especially knees and shoulders. The patient undergoes anesthesia and a device is inserted into the joint through a small incision, enabling a view of the interior structures, including bone, ligament, tendons, cartilage, etc.

The new study confirmed findings of older research that suggested that for many patients with meniscal tears, physical therapy offers equivalent or better outcomes than surgical repair.

The surgery, called arthroscopic partial meniscectomy, involves identifying the damaged tissue and trimming and smoothing the torn bits.

The study isn’t a call to cease this procedure, just to use it more selectively. Some patients, the researchers said, are good candidates for it, including younger people and those whose problem is the result of an acute sports injury. “But,” The Times reports, “about 80 percent of tears develop from wear and aging, and some researchers believe surgery in those cases should be significantly limited.”

Patients in the new study all received anesthesia and incisions. But only some got the actual surgery; others got simulated procedures. They did not know which they had received.

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

The art of this science now appears to be who is the best candidate for slicing and dicing, and who should hit the gym under the watchful eye of a physical therapist?

Pain alone isn’t a driving diagnostic determinant. One consideration for the suitability of surgery is if knee pain is caused by the torn meniscus or something else, such as osteoarthritis, which often accompanies tears. Another possible factor is whether mechanical knee function is affected. Is the knee locking? Is it unstable?

“Take 100 people with knee pain; a very high percentage have a meniscal tear,” Dr. Kenneth Fine, an orthopedic surgeon, told The Times. “People love concreteness: ‘There’s a tear, you know. You have to take care of the tear.’ I tell them, ‘No. 1, I’m not so sure the meniscal tear is causing your pain, and No. 2, even if it is, I’m not sure the surgery’s going to take care of it.”

Some experts believe that even if surgery seems appropriate at some point, little is lost by trying physical therapy first, for something like six months. Any time you can avoid an invasive procedure and hospitalization, with their added risks of infection and other complications, you should exercise that option.

The new study admittedly was small – five hospitals and 146 patients, ages 35 to 65, with wear-induced tears and knee pain. About half of the subjects had mechanical problems such as locking or clicking knees.

Skeptics were concerned that it involved patients with only meniscal tears, not arthritis. They wondered if the tears were small, if the pain was caused by the kneecap, which would be complicating factors. One of the study’s authors said whether meniscal tears caused the participants’ pain was unknown, but that arthritis was an unlikely cause, because the patients didn’t seem to have it. About 1 in 10 meniscal tear patients have no arthritis, he said.

Most patients received spinal anesthesia, and remained awake, although some got general anesthesia. As described by The Times, “Surgeons used arthroscopes to assess the knee. If it matched study criteria, nurses opened envelopes containing random assignments to actual or sham surgery. In real surgery, shaver tools trimmed torn meniscus; for fake surgery, bladeless shavers were rubbed against the outside of the kneecap to simulate that sensation. Nobody evaluating the patients later knew which procedure had been received.”

After a year, each group reported similar improvement; two in the surgery group needed further surgery, and five in the fake-surgery group requested it.