Washington - There is little to no evidence that two kinds of medical procedures that involve injecting cement to fuse fractured vertebrae -- called vertebral augmentation -- to relieve back pain actually work, researchers said Thursday.
Hundreds of thousands of patients suffer chronic back pain each year due to fractured vertebrae, and the procedures, known as percutaneous vertebroplasty and balloon kyphoplasty, were "introduced into practice before high-quality evidence" was available, said the study in the Journal of Bone and Mineral Research.
Despite the lack of evidence, the procedures are often considered "part of standard routine care," said the report by a global task force of bone health experts.
France was a pioneer of the method, which has gained popularity in the last two decades, is reimbursed by insurance in many countries, and has been seen as a miracle treatment by some satisfied patients who say it relieved their chronic pain.
But only five clinical trials have been conducted on vertebroplasty, and the experts' review found that the technique does not relieve pain any better than a placebo operation in the two years afterward.
To study the effects of the operation, versus the perceived effects of having an operation, researchers compared patients who underwent the actual procedure to a control group that had a pain injection into the spine but never received the fusion.
The experiments were blinded, meaning that patients did not know which group they were in.
The more popular, and more expensive technique, which uses a balloon, has not been studied compared to a placebo.
"Evidence of the value of this procedure is reliant on low-quality evidence from trials that have compared kyphoplasty with usual care or head-to-head comparisons with vertebroplasty," said the report.
So why have doctors continued to support an operation that carries risks such as infection at the site of the injection, cement leakage, and complications from anesthesia?
"The reason is, people with acute painful vertebral fractures are desperate because they have severe pain, but the natural history of the pain is to get better over four to six weeks," lead author Peter Ebeling told AFP.
If pain continues for months, patients may benefit from the cement injections, but evidence is still lacking, he added.
Other approaches include pain medications, wearing a back brace, and physical exercise.
Patients may also be advised to take drugs to ward off bone loss from osteoporosis, in order to avoid future fractures.
In the United States, at least 300,000 people underwent such operations from 2005 to 2010, 27 percent involving vertebroplasty and the rest balloon kyphoplasty.