Two studies concluded in 2009 that a common repair for spinal compression fractures in people who have osteoporosis offers no more benefit than a sham injection and may carry serious risks, experts said Wednesday.

The studies, which were published in The New England Journal of Medicine, were the first clinical trials to test a popular and expensive procedure called vertebroplasty against a placebo, and many experts said they were stunned by the results, which showed that patients got equal amounts of modest pain relief whether they got vertebroplasty, where bone cement is pumped into broken vertebrae, or a dummy injection.

David F. Kallmes, MD, an interventional radiologist at the Mayo Clinic in Rochester, Minn., who led one of the studies, said he thought something was wrong with the data when he finally learned the results.

“I just really couldn’t believe it when they told me,” Dr. Kallmes said in an interview. (In double-blinded clinical trials, neither researchers nor patients are allowed to know who is getting the investigational treatment or the placebo.)

Dr. Kallmes said he was relieved to learn that a team of Australian researchers had gotten roughly the same results in a similar study.

“I think both trials show that vertebroplasty is no better than a sham procedure for either improving pain, function or quality of life,” said Rachelle Buchbinder, PhD, a rheumatologist and director of the Department of Clinical Epidemiology at Cabrini Hospital in Malverne, Australia.

“I don’t think there’s any benefit of having a vertebroplasty and there are potential risks, and they haven’t really been fully elucidated to date,” Dr. Buchbinder added.

In her study, which enrolled 78 patients with spine fractures, one participant who received the cement developed a serious bone infection called osteomyelitis.

And previous research has suggested that bone cement may increase the risk for fractures in adjacent vertebrae because it changes the way the spine is able to absorb shock.

Still, other experts said that while they found the studies to be rigorous and well designed, the results were tough to reconcile with personal experience.

 “I have seen patients come into the O.R. in so much pain that they could not walk,” says Scott Boden, MD, director of the Emory Spine Center in Atlanta, who was not involved in either study. “They get the cement and two minutes later they are walking out the door. It’s that fast.”

Such cases have convinced many in the medical community that the procedure works, and Dr. Boden said he believes the procedure may still have benefit for certain kinds of patients, particularly in those who have recent fractures.

During the previous six years, the number of vertebroplasty procedures performed in the United States has doubled, according to Medicare data, from 4.3 to 8.9 procedures for every 1,000 persons, though questions and worries about the risks remained. 

And vertebroplasty is expensive. The total cost is usually around $5,000 when the cost of an MRI scan is included.