Mary Ann Moon is a freelance writer in Clarksburg, Md.
Vertebroplasty was no more beneficial than a sham procedure for painful osteoporotic vertebral fractures in the first two blinded, randomized, controlled trials ever to assess the technique, according to separate reports in the New England Journal of Medicine.
These findings are likely to transform percutaneous vertebroplasty—a widely accepted method of pain relief that has become routine therapy—from “a procedure that is virtually always considered to be successful” into one “considered no better than placebo,” James N. Weinstein, DO, of Dartmouth-Hitchcock Medical Center, Hanover, N.H., said in an editorial published with the reports.
Public institutions such as the Centers for Medicare & Medicaid Services, as well as radiological and neurological surgery societies, have recommended reimbursement of vertebroplasty—endorsements that have boosted a dramatic rise in its popularity. The number of vertebroplasties performed in the United States has more than doubled in the past 6 years, Dr. Weinstein noted (N. Engl. J. Med. 2009;361:619–21). The procedure involves injecting medical cement directly into a vertebral fracture to stabilize it and immediately relieve pain. Many case series and small, unblinded, nonrandomized, uncontrolled studies have suggested that it is effective, though the precise mechanism of action has never been delineated.
In one of the reports, Rachelle Buchbinder, PhD, of Monash University, Malvern, Australia, and her associates randomly assigned 38 patients with one to two recent vertebral fractures to vertebroplasty and 40 to a sham procedure.
The primary outcome measure, overall pain score, was no different between the two groups at 1-week, 1-month, 3-month, or 6-month assessments. Pain at rest, pain during the night, physical functioning, and quality of life measures also were not significantly different, nor was the use of opioid analgesics (N. Engl. J. Med. 2009;361:557–68).
These results were consistent regardless of patients' duration of symptoms and history of previous fractures.
One subject who got vertebroplasty and could not receive prophylactic cephalothin because of allergy developed an adjacent new fracture and osteomyelitis requiring surgery. Some studies have suggested that vertebroplasty raises the risk of subsequent fractures, particularly in adjacent vertebrae where the medical cement has leaked.
“Our results show … the hazards of relying on the results of uncontrolled or poorly controlled studies to assess treatment efficacy,” Dr. Buchbinder and her colleagues noted.
Earlier studies may have overestimated the benefit of vertebroplasty “by failing to take into account the favorable natural history of the condition, the tendency of regression to the mean, and the placebo response to treatment, which may be amplified when the treatment is invasive,” they added.
In the other study, David F. Kallmes, MD, of the Mayo Clinic, Rochester, Minn., and his associates enrolled patients at 11 medical centers in the United States, the United Kingdom, and Australia; 68 were randomly assigned to vertebroplasty and 63 to a sham procedure.
At 1 month, the two groups did not differ significantly on the two primary outcomes, which were separate measures of pain and disability. Secondary outcomes of pain intensity, disability, and quality of life also were not significantly different, Dr. Kallmes and his colleagues said (N. Engl. J. Med. 2009;361:569–79).
One patient who underwent vertebroplasty sustained an injury to the thecal sac during the procedure and required hospitalization, they added.
Dr. Buchbinder reported grant support for the trial from Cook Australia, a manufacturer of medical products and devices. Dr. Kallmes received consulting fees from Zelos Therapeutics and support from ArthroCare, Stryker, Cardinal, and Cook and served as an unpaid consultant to Bone Support. Dr. Weinstein reported no disclosures.
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