BOSTON (Reuters) – Surgery works no better than drugs and physical therapy for older people suffering knee pain from osteoarthritis, researchers reported on Wednesday.

Even signs of a tear in the rubbery tissue that supports the knee may not be a good reason for surgery, according to two studies in the New England Journal of Medicine.

The research could affect the way doctors treat common knee pain, the researchers said.

Except in clear cases of knee trauma, “I don’t think this surgery really should be used at all,” said Dr. Brian Feagan of the University of Western Ontario.

His team evaluated arthroscopic debridement surgery, in which doctors put fluid into the joint to wash it out while they surgically smooth rough surfaces.

In the study that followed 178 volunteers, most over 50, Feagan’s team found that people who were treated non-surgically did just as well after two years as patients who had surgery.

“Patients assigned to arthroscopic surgery were no more likely to improve with respect to physical function, pain, or health-related quality of life than were those assigned to the control group,” the researchers wrote.

The findings reinforce a study published six years ago showing that patients who received surgery did no better than volunteers who got a sham operation.

The second study involved 991 randomly selected people aged 50 to 90. It found that 60 percent of those with osteoarthritis but no knee symptoms nonetheless had a meniscal tear, sometimes known as a torn cartilage, that showed up on an MRI.

The rate was almost identical among people who reported knee pain, aching or stiffness on most days.

Among the people without evidence of osteoarthritis, sometimes known as “wear-and-tear arthritis,” 23 percent of the volunteers without knee pain nonetheless showed signs of a tear, versus 32 percent of those who reported pain.

Three out of five meniscal tears were in people who reported no symptoms during the previous month.

“If you’ve got knee osteoarthritis, your doctor gets an MRI, and there’s a meniscal tear there, you don’t necessarily want to do anything about it,” David Felson of Boston University Medical School said in a telephone interview.

“Identifying a tear in a person with knee pain does not mean that the tear is the cause of the pain,” Dr. Robert Marx of Cornell University added in a commentary.

Feagan and Felson stressed that the findings do not mean that all arthroscopic surgery is unnecessary.

(Editing by Alan Elsner and Maggie Fox)