Cutting question

The 76-year-old Burlington resident, a former state representative, was so hobbled by back bones thinned and fractured from cancer, she feared she would spend the rest of her life in a wheelchair.

That was before doctors at Massachusetts General Hospital injected cement into Brenton’s spine to stabilize her compression fractures. The minimally invasive surgery, known as vertebroplasty, is under scrutiny after two recent studies in the New England Journal of Medicine concluded the popular treatment to ease pain from back fractures, typically caused by osteoporosis, is no more effective than a sham surgery. Coming more than a decade after vertebroplasty was introduced in this country, the studies are the first to compare the treatment’s effectiveness to a placebo surgery, the gold standard for medical research.

Yet the findings are unlikely to change the practice of many specialists, who said they don’t jibe with their years of experience. Vertebroplasty, they said, has often provided their patients relief from a very painful condition when more conservative options - medications, braces, or bed rest - have not.

Many also said the conclusions raised more questions than answers. The fallout illustrates how hard it is to find clear-cut answers about whether health care dollars are being wisely spent, a key question as Congress debates a national overhaul of the health care system. President Obama has promoted such “comparative effectiveness research’’ as a way to cut costs and improve quality.

The studies’ tsunami-like aftershocks - insurers are now reconsidering whether they will continue to pay for the treatment - also underscore a little-known fact outside the medical community: Surgeries often become widespread before they’ve undergone rigorous evaluation. While prescription drugs and medical devices must be reviewed by federal regulators before they’re released to the public, surgical procedures do not.

“The surgery has saved my sanity,’’ said Brenton, who was surprised to hear about the latest studies.

“The pain in my lower back was gone when I came out of the anesthesia,’’ she said. “It was immediate. It was unbelievable.’’

Dr. Joshua Hirsch, the MGH interventional radiologist who did Brenton’s surgery, said he would certainly include information about the latest vertebroplasty studies when his patients are considering their treatment options. But he will continue to recommend the surgery because he has seen its benefits.

“I bow at the altar of evidence-based medicine. I believe in it, and sometimes there will be evidence that I don’t like that will require a change in my practice,’’ Hirsch said. “These studies are important, but they don’t overrule all the other data out there.’’

Dr. Michael Schafer, chairman of the Department of Orthopaedic Surgery at Northwestern University Medical School and a board director of the American Academy of Orthopaedic Surgeons, said he, too, will continue to recommend vertebroplasty.

The two latest studies that have raised questions, he said, did not, for instance, address whether the surgery may be more helpful than a placebo if it is offered soon after a back fracture, as opposed to months later, when more conservative treatments have failed.

The studies also did not address whether vertebroplasty heads off curvature of the spine, a common side-effect of such fractures, Schafer said.

“Both of these studies are really good starts, but they are not the final answer,’’ he said. “We need more evidence-based guidelines on the work.’’

In the two new studies - one conducted in the United States, the other in Australia - all patients were injected with the same local anesthetic, but those in the control group received no incision or cement injection. Instead, doctors tapped on their numbed backs, simulating a cutting action, while cement was mixed in the operating room so the procedure smelled authentic. The American study followed 131 patients for one month after surgery, while the Australians enrolled 78 patients and monitored 71 of them for up to six months.

Even some of the surgeons who conducted the studies were surprised at the results.

“Physicians who do this procedure know that patients get better,’’ said Dr. Harry Cloft, professor of radiology and neurosurgery at the Mayo Clinic, and a co-investigator on the American study. “But to tell them it doesn’t work flies in the face of their everyday experience.’’

Cloft was a member of the surgical team that introduced vertebroplasty in the United States in 1997. Just two years ago, his colleagues at the Mayo Clinic published the results of a large-scale - 1,000 patients - study that concluded that “practitioners can quote a high success rate and low complication rate for vertebroplasty’’ when making treatment recommendations. But this study was based only on patients who had the surgery, so no comparison was made to those who had more conservative treatments.

Still, Cloft said that he and his colleagues haven’t given up on the procedure. They plan to explore whether there are certain subgroups of patients - perhaps those whose fractures are only a few months old - who may draw more benefit from the surgery, compared to injection of anesthetic only. Their study had enrolled patients as much as a year after a fracture.

Since completing their study, Cloft said, he and his colleagues have become more conservative in offering vertebroplasty and suggest patients first try what is, in essence, the sham surgery - injecting anesthetic, but no cement, into the back. The Mayo Clinic study noted that the half-life of the local anesthetic used in the surgery (sham and real) is only 3 hours, meaning it is unlikely that the drug would have long-lasting pain-relief effects. They are tracking the outcomes.

What inspired Cloft and his colleagues were studies like the 2002 research from the US Department of Veterans Affairs that found the type of surgery performed on thousands of Americans annually with arthritic knees to relieve pain was actually no better than a sham procedure.

Medicare, the country’s largest insurer, stopped paying for the operation in 2004, but it is not clear that doctors have stopped doing it. There is no national tracking system.

Now, Medicare officials are considering whether to continue paying for vertebroplasty. So is Blue Cross Blue Shield of Massachusetts, the state’s largest private insurer. For years, Blue Cross had not covered it, citing a lack of definitive evidence. But coincidentally, just days before the studies were published, Blue Cross decided the evidence was there, and reversed its position. The company is now reconsidering, again. It is seeking an “expedited re-review’’ of all of the science, said spokeswoman Tara Murray.

The controversy perfectly illustrates why the US should more carefully study surgical procedures before they become widely available to the general population, said Dr. James N. Weinstein, director of the Dartmouth Institute for Health Policy and Clinical Practice.

The Dartmouth-Hitchcock Medical Center, where Weinstein chairs the Department of Orthopaedic Surgery, tracks how its patients have fared over time with various spine surgeries, and posts results online to help other patients consider their treatment options. The center’s online system does not track vertebroplasty.

“Most doctors have a feeling their patients are doing well,’’ he said, “but they don’t actually measure.’’

But Brenton, the Burlington cancer patient who had vertebroplasty in the spring, has taken stock and concluded the surgery has given her measurable relief. So much so, that she is scheduled for another this fall, to heal one last fracture.

“I still have pain on the side of my ribs,’’ she said. “I am hoping the last procedure will take care of that. It took care of the others.’’

Kay Lazar can be reached at klazar@globe.com.