Canada ? Arthroscopic knee surgery for arthritis – a procedure performed hundreds of thousands of times a year – does not reduce joint pain or improve knee function, according to new research released Wednesday. The study of 178 adults with moderate to severe arthritis found the surgery, in which damaged bone and cartilage are removed through tiny incisions, had no benefits beyond nonsurgical treatments, such as physical therapy.

The report in the New England Journal of Medicine confirmed the results of a 2002 study that caused many orthopedic surgeons to discontinue the practice. Others continued to perform the surgeries, dismissing the earlier study because its subjects were predominantly men.

The latest report should put all doubt to rest, said Dr. Brian G. Feagan, a professor of medicine at the University of Western Ontario in Canada and a study author.

“We now have two data points saying the surgery is ineffective for arthritis,” he said. “It should not be performed.”