Dr. Kallmes has begun a small, pilot study, he said, in which patients are given only the numbing drugs to see if they alone can help. But he said he was not ready to give up on vertebroplasty. He said more studies were needed to determine whether there were specific subgroups of patients for whom it might work. People who want the treatment should still be able to get it, he said  but only if they enter a clinical trial that collects data on every case.

In an editorial accompanying the articles, Dr. James N. Weinstein, director of the Dartmouth Institute for Health Policy and Clinical Practice, said, “Compassionate care and tincture of time, in and of themselves, can have an effect.”

In an interview, Dr. Weinstein, who does not perform vertebroplasty, suggested that rather than abandoning the procedure, doctors could let patients decide for themselves, by telling them, “This is a treatment option no better than a placebo, but if you want to consider a placebo because you might benefit from it, you might want to know that.”

Dr. Robert R. Recker, president of the National Osteoporosis Foundation, said the group had not taken a stand on vertebroplasty. He also leads the osteoporosis research center at Creighton University, in Omaha, and said he had referred patients for the treatment, and thought it helped some. Despite the new findings, he does not think it should be abandoned.

“I think there needs to be more studies,” Dr. Recker said.

Dr. Kallmes said the only way medical practice would change would be if Medicare and other insurers were to stop covering vertebroplasty or to cover it only when it was part of a study. But patients might still be able to get a similar procedure that also uses cement, kyphoplasty, which has been growing even faster than vertebroplasty  also without placebo-controlled studies.

Susan Pisano, a spokeswoman for America’s Health Insurance Plans, a trade group for private insurers, said that so far there had been “considerable coverage” of vertebroplasty, but the new evidence could change that.

Dr. Marcel E. Salive, a director in the Medicare division that decides what treatments to cover, said Medicare had no national policy on vertebroplasty and had been letting the states decide. They have been covering it. Dr. Salive said Medicare had looked into the treatment in 2005 but found a lack of randomized, controlled studies. The new studies provide “the kind of evidence we look for when making coverage policy,” he said. But he said it was too soon to tell whether the research would affect coverage.