On Jan. 24 1978, the New Zealand governor-general referred to a Commission of Inquiry an investigation to determine the desirability of providing for reimbursement of chiropractic benefits under the New Zealand Social Security Act and the New Zealand Accident Compensation Act. The commision's findings would impact chiropractic worldwide for decades to come.
Update on Vertebroplasty: New Research Is Revealing
A few years ago, I wrote an article (May 22, 2006 issue) reviewing vertebroplasty as a treatment option for painful compression fractures due to osteoporosis.1 I felt that as chiropractors, we should be aware of the common medical procedures that are available to treat disorders we generally manage; osteoporotic compression fractures being one such entity. From the information available at the time, vertebroplasty was considered a reasonable treatment option for painful osteoporotic vertebral compression fractures.
A recent article in the The New England Journal of Medicine has changed my impression of vertebroplasty. The article reported on a multicenter clinical trial evaluating the efficacy of percutaneous vertebroplasty for the treatment of painful osteoporotic vertebral compression fractures.2 In the study, patients who had one to three painful osteoporotic vertebral compression fractures were randomly assigned to undergo either vertebroplasty or a simulated procedure without cement (the control group). Participants could have up to two spinal levels treated.
Participants were enrolled in the study for one year and were evaluated at entry and at one month and 12 months; and with phone calls at days one, two, three and 14, and months three and six. After month one, crossover from the placebo group to the vertebroplasty group was allowed.
Kallmes, et al., reported that pain and disability outcomes at one month in the group of patients who underwent vertebroplasty were similar to those in a control group that underwent a sham procedure. Both groups showed improvement within three days after either procedure. The cutoff for the primary outcome was one month (prior to crossover), but data were collected for three months.
Interestingly, patients who crossed over had worse outcomes than those who did not request the other intervention. More patients than predicted were able to guess which treatment they had received; therefore, there might have been a benefit in understanding the treatment effect in those who guessed their treatment accurately.
Kallmes' conclusions were as follows: "At 1 month, clinical improvement in patients with painful osteoporotic vertebral fractures was similar among those treated with vertebroplasty and those treated with a simulated procedure. These data suggest that further studies should be undertaken to determine whether the long-term outcome is similar in the two groups, especially because our crossover study design limited our ability to shed light on the long-term efficacy of vertebroplasty."
The authors do note that there were several limitations in regard to this trial:
- They were forced to allow crossover after one month because both physicians and patients were reluctant to accept a longer period.
- They did not compare the study groups with respect to other medical treatments they received that might have affected their outcomes.
- They did not consider that the persistence of pain after vertebroplasty or fracture healing might be due to causes of pain other than fracture; they did baseline imaging only to exclude other pathology.
- They did not examine the possibility that vertebroplasty is effective only for fractures of a certain age or healing stage.
- They limited the study to vertebroplasty and did not evaluate the efficacy of kyphoplasty, which is similar.
Another trial, this one by Buchbinder, et al.,3 and reported in the same issue of NEJM, measured pain, quality of life, and functional status at one week and at one, three and six months after active and sham vertebroplasty, finding no significant between-group differences at any time point, which further validates Kallmes' findings. As in the Kallmes study, the patients in the two study groups had improvement in pain. What is interesting also is that in both trials, the placebo procedure involved the injection of a short-acting analgesic into the bony periosteum containing nociceptive fibers. One might question whether or not the sham was an active treatment, given the fact that there was no significant difference in results between the two treatments.
Considering the increasing use of vertebroplasty, the limited benefit and the potential risks, such as soft-tissue damage, nerve-root pain and compression related to the possible leakage of bone cement (to name the most common potential complications), one wonders how often vertebroplasty should be performed, if at all.
It's estimated that there are 750,000 compression fractures due to osteoporosis in the United States. Only a third of patients receive treatment for these fractures and still the annualized direct-care expenditures for osteoporotic fractures in the U.S. was estimated to range from $12 billion to $18 billion in 2002.4 I have not been able to find data covering 2003-2008, but one can be certain that the costs have not decreased.
Pain associated with these fractures can be excruciating, and before the advent of percutaneous vertebroplasty, treatment options were mainly limited to conservative management, which often meant pain medications and bed rest. (I'm not aware of any clinical trial in which chiropractic treatment was evaluated, even though many chiropractors do treat patients with compression fractures with good results.) Vertebroplasty has been used since the mid-1990s in the U.S. and since the mid-1980s in France, where it was developed.
In the past six years, the number of vertebroplasty procedures performed in the U.S. has doubled, according to the Centers for Medicare & Medicaid Services, and yet until these two recent studies, research on the efficacy of the procedure had been limited to uncontrolled, nonblinded, small case studies. Two unblinded trials have compared vertebroplasty with "medical" management; one showed better pain relief with vertebroplasty at one day and two weeks,5 and the other showed no significant difference at three months.6 No blinded trials had been performed or reported until recently. None of the case studies takes into account important variables including the natural tendency for compression fractures to heal spontaneously, regression toward the mean, and the placebo effect.7
What I find most disconcerting in light of the recent findings is that vertebroplasty has been used for past 20 years, but only now has it been reviewed for its clinical efficacy. I am summarily guilty as charged; even after reviewing the literature and reporting that this might be an option for some patients with painful compression fractures, I failed to recognize that there were no unblinded trials that confirmed this procedure's clinical efficacy. My assumption was that it certainly must have some clinical efficacy if Western medicine had been using the procedure for 20 years!
Obviously we all need to use a more discerning eye when evaluating procedures and treatments offered to the public. Unfortunately, this information isn't always easily available or easily understood. Clearly there needs to be a paradigm shift toward conducting research that provides sufficient clinical efficacy for procedures before they become common practice.
It will be interesting to see if the number of vertebroplasty procedures is significantly reduced in response to this reported lack of efficacy or whether kyphoplasty procedures will actually become more popular, since vertebroplasty's efficacy has still been so poorly scrutinized thus far.
References
- Pate D. "Vertebroplasty for Compression Fractures." Dynamic Chiropractic, May 22, 2006.
- Kallmes DF, Comstock BA, Heagerty PJ, et al. A randomized trial of vertebroplasty for osteoporotic spinal fractures. N Engl J Med, 2009;361:569-579.
- Buchbinder R, Osborne RH, Ebeling PR, et al. A randomized trial of vertebroplasty for painful osteoporotic vertebral fractures. N Engl J Med, 2009;361:557-568.
- Carmona RH, Office of the Surgeon General. Bone Health and Osteoporosis: A Report of the Surgeon General. Rockville, MD: Department of Health and Human Services, 2004.
- Voormolen MH, Mali WP, Lohle PN, et al. Percutaneous vertebroplasty compared with optimal pain medication treatment: short-term clinical outcome of patients with subacute or chronic painful osteoporotic vertebral compression fractures: the VERTOS Study. Am J Neuroradiol, 2007;28:555-560.
- Rousing R, Andersen MO, Jespersen SM, Thomsen K, Lauritsen J. Percutaneous vertebroplasty compared to conservative treatment in patients with painful acute or subacute osteoporotic vertebral fractures: three-months follow-up in a clinical randomized study. Spine, 2009;34:1349-1354.
- Weinstein JN. "Balancing Science and Informed Choice in Decisions About Vertebroplasty." N Engl J Med, 2009;361:619-621.