Tuesday, October 20, 2009

Questions raised over vertebroplasty for osteo fractures

Medical Tribune September 2009 P12
David Brill

Vertebroplasty performs no better than a placebo procedure for treating painful osteoporotic fractures, two major new studies have found.

Despite its widespread usage and recommendation in guidelines, vertebroplasty did not relieve pain, alleviate disability or improve quality of life compared to sham interventions, US and Australian researchers reported.

The studies are the first true randomized controlled trials to assess a procedure which has become a firmly established treatment for osteoporotic fractures. The number of vertebroplasties performed in the US, for example, almost doubled from 2001 to 2005. [JAMA 2007 Oct 17;298(15):1760-2]

The jury is still out as to how the findings will influence practice, according to an orthopedics expert whose editorial accompanies the papers in the New England Journal of Medicine. [2009 Aug 6;361(6):619-21]

“Although the trials by Kallmes et al. and Buchbinder et al. provide the best available scientific evidence for an informed choice, it remains to be seen whether there will be a paradigm shift in the treatment of vertebral compression fractures with vertebroplasty or similar procedures,” wrote Dr. James Weinstein, chair of the department of orthopedic surgery at Dartmouth-Hitchcock Medical Center, US.

Given the rise in the number of vertebroplasties and the questionable risk-benefit ratio, it is now essential that patients be well informed about the procedure, added Weinstein.

“When faced with several choices for which the evidence is less than clear, patients and doctors must thoroughly review the options together. Informed choice helps to educate patients about treatment options and allows them to recognize that a decision can be based on their values and preferences,” he wrote.

The larger of the two trials, led by Dr. David Kallmes of the Mayo Clinic, Rochester, US, followed 131 patients with osteoporotic vertebral compression fractures. They received either vertebroplasty or a simulation procedure in which cement was not injected into vertebrae. [N Engl J Med 2009;361:569-79.]

At 1 month there was no difference between groups on a pain scale ranking intensity from 0 to 10 (difference 0.7; 95% CI -0.3 to 1.7; P=0.19) or on the Roland-Morris Disability Questionnaire (difference 0.7; 95% CI -1.3 to 2.8; P=0.49). There was however a non-significant trend for more patients in the vertebroplasty group to report clinically meaningful improvements in pain (64 percent versus 48 percent; P=0.06).

Patients were subsequently allowed to cross over and receive the other intervention – still unaware of which they had already received. At 3 months, this option had been taken up by more control patients than vertebroplasty patients (43 percent versus 12 percent), but all patients who crossed over reported comparable or worse outcomes than those who received only the first intervention.

The second trial, led by Dr. Rachelle Buchbinder of Monash University, Australia, reported 6-month follow-up of 35 vertebroplasties and 36 placebo interventions. [N Engl J Med 2009 Aug 6;361(6):557-68]

Both interventions did relieve pain but to a comparable extent: at 3 months, the mean reductions (also measured on a 10-point scale) were 2.6 in the vertebroplasty group and 1.9 in the control group (adjusted between-group difference 0.6; 95% CI -0.7 to 1.8). This difference was also not significant at 1 week or 1 or 6 months; nor was there anything nothing to choose between groups on a range of secondary outcomes, including physical functioning and quality of life.

“It has been argued that performing a randomized, placebo-controlled trial of vertebroplasty is unnecessary and unethical in view of the published results of numerous studies that suggest a benefit of vertebroplasty. Our results show – not for the first time – the hazards of relying on the results of uncontrolled or poorly controlled studies to assess treatment efficacy,” the authors wrote.

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