Vertebroplasty appears no better than placebo for painful osteoporotic spinal fractures, and has potential to cause harm

Vertebral fractures are a common manifestation of osteoporosis, and up to half such fractures result in severe pain and disability. Although most heal within weeks or a few months, some people experience persisting discomfort. Best supportive care includes bed rest, analgesia and physical therapy, and some patients require hospitalisation.

Vertebroplasty, the percutaneous injection of polymethylmethacrylate (PMMA) into the affected vertebral body, has been widely accepted to be a safe and effective treatment for vertebral fractures on the basis of observational and quasi-experimental studies.1 Despite a lack of evidence from randomised controlled trials on which to base reimbursement decisions, some countries, including Australia, have recommended public funding of the procedure.2,3 Since being listed on the Medicare Benefits Schedule in November 2005, about 600 to 700 vertebroplasties have been performed in Australia annually (not including those performed in public hospitals),4 and at least 40 000 are performed in the United States annually.5

The results of the first two randomised placebo-controlled trials investigating this procedure have now been published in the New England Journal of Medicine.6,7 In the first study, performed in Australia, 78 participants with one or two acute osteoporotic vertebral fractures were randomly assigned to undergo either vertebroplasty or a placebo procedure (Box 1).6 To simulate the real procedure, patients in the placebo group underwent gentle tapping of a stylet resting on the affected vertebral body, and PMMA was prepared so that its smell permeated the room. All participants and research personnel other than those performing the procedure were blinded to treatment allocation.

Vertebroplasty did not result in a significant advantage over placebo in any measured outcome at any timepoint, and pain reduced in both the treatment and placebo groups over time (Box 1). Similar improvements were seen in both groups with respect to pain at night and at rest, physical functioning, quality of life, and perceived improvement. Seven new vertebral fractures (three in the vertebroplasty group and four in the placebo group) occurred during the 6 months of follow-up, and one of these patients in the vertebroplasty group also developed osteomyelitis.

In the second study, which was based in the US, but also included sites in the United Kingdom and Australia, 131 patients with between one and three painful osteoporotic vertebral fractures were randomly assigned to undergo vertebroplasty or a sham procedure (Box 2).7 The control group underwent local infiltration with local anaesthetic, but no stylet was inserted, and PMMA was also prepared so that the odour would permeate the room. Patients in both groups were allowed to cross over to the other procedure at 1 month or later if they wished because adequate pain relief had not been achieved.

As in the Australian study, there were no clinically or statistically significant differences between groups at any timepoint up to, and including, 1 month for any of the primary or secondary outcomes measured. At 1 month, there was no significant difference between the treatment and control groups on either the Roland Morris Disability Questionnaire or the pain rating. One patient in the vertebroplasty group had an injury to the thecal sac during the procedure, resulting in the patient requiring hospitalisation.

The negative findings of these two trials are supported by the findings of two open randomised trials of vertebroplasty versus usual care.8,9 One of these included 34 participants, and allowed crossover to the vertebroplasty group after 2 weeks in cases of persisting pain.8 At 2 weeks, the mean pain scores were similar between the two groups. The other open randomised trial included 50 patients who had had a short duration of symptoms (40 patients, < 2 weeks; 10 patients, 2–8 weeks).9 Outcomes at 3 months indicated no differences between the vertebroplasty and usual care groups for any of the measured endpoints. There were two adjacent fractures in the group that underwent vertebroplasty and none in the usual care group.

These trials provide the best evidence we have to date on the value of vertebroplasty for treating painful osteoporotic vertebral fractures. Based on these data, vertebroplasty appears to confer no benefit over placebo, but poses some risk. Apart from the immediate risks of cement leakage, infection and injury to the spinal cord, vertebroplasty may increase the risk of further vertebral fracture. Both the Australian and US studies are ongoing, and will provide valuable additional data on this risk.

Lower-quality studies are often biased in favour of interventions that are later shown in high-quality controlled trials to be ineffective.10 Findings from our two methodologically rigorous, randomised placebo-controlled trials show, not for the first time, the importance of establishing the efficacy of new procedures in well conducted, appropriately designed clinical trials before they are widely promoted and adopted into clinical practice. In light of the new evidence, the decision to list vertebroplasty for the treatment of osteoporotic vertebral fractures on the Medicare Benefits Schedule will be reviewed by the Medical Services Advisory Committee later this year. Treatment of painful vertebral fractures should continue to be best supportive care focused on pain management and maximising function. Attention to minimising risk of further fracture, including treatment of osteoporosis and other risk factors is also advisable.