Although the patients were unaware which treatment they received, both the cement-injected and sham-treated groups reported similar levels of reduced pain and disability in a follow-up questionnaire a month later. A similar study on 71 Australians had the same results six months after the procedure.

Sham now offered as treatment

David Kallmes, M.D., lead researcher on the Mayo Clinic study, said the researchers don’t know why the patients fared just as well with the vertebroplasty as with the sham treatment. It may be that the pressure from the shot of local anesthetic provided relief or that the fracture was already on its way to natural recovery by the time it was treated. It could also be that patients who believed they were getting the cement treatment felt better because of a placebo effect, but Kallmes says that option seems unlikely.

Any placebo effect should not have lasted for the month of follow-up in the Mayo study or the six months of follow-up in the Australian study. “Just the other day a woman came in who had the sham treatment a year ago and she still refuses to believe that she didn’t get the real cement treatment,” Kallmes says.

In light of the findings, the Mayo Clinic is now telling its patients to try the local anesthetic that was used as the sham treatment before vertebroplasty, says Harry Cloft, M.D., a Mayo Clinic radiologist who performed some of the procedures for the federally funded Mayo study. The anesthetic injection is performed free of charge, but is done on the condition that patients agree to be part of a trial looking at whether or not anesthetic alone helps.

Still, some patients continue to request vertebroplasty, and the Mayo Clinic performs it on patients who want it—though they are reviewing that policy. The lead author of the Australian study is not recommending vertebroplasty or the anesthetic injection for her patients.

“We know that vertebroplasty works. Patients feel relief,” says J. Kevin McGraw, M.D., an interventional radiologist who performs about 300 of the procedures each year in Columbus, Ohio, and wrote the guidelines for the procedure for the Society of Interventional Radiology. “We now know that patients who had the needle stuck in their backs to inject the anesthetic [for the sham treatment] felt better as well,” he says.

McGraw still offers the traditional procedure to his patients and says that the small study size and the fact that many eligible patients opted not to be included may mean the study does not present the full picture. McGraw says he receives royalties for a device he helped develop that delivers and mixes medical cement.

Dina Fine Maron covers health, science and politics.

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