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

TO THE EDITOR: The editorial by Buchbinder et al suggesting that the effectiveness of vertebroplasty has been determined by the two studies she and her co-authors published is misleading. Both studies contain major flaws. In both, 70% of eligible patients declined to participate. No details of these patients are published, but they may have been the patients with more severe pain. The median duration of pain in the Australian study was 9 weeks (compared with 16 weeks in the US study); only 30% of patients had pain for less than 6 weeks. No information on the need for hospitalisation because of severe pain was given in either study. The average length of hospital stay was not published. In the Australian study, the inclusion criteria were the presence of back pain of less than 12 months’ duration and the presence of one or two recent fractures. In this group of patients, whose average age was 74 years, there will be many possible causes of back pain. The fracture may be the main cause of pain, a partplayer, or may not be significant. In patients with milder pain and longer duration of pain, non-fracture causes are more likely. In the US study, patients were selected on the basis of x-ray unless the fracture “was of uncertain age”. I have performed an audit of my practice and found that in patients with an unequivocal x-ray diagnosis of fracture level, magnetic resonance imaging (MRI) identified another fracture not seen on x-ray in 23 of 63 patients (36%), and in 10 of the 63 patients (16%), a fracture that was presumed acute showed no oedema on MRI. In the Australian study,2 the experience of the radiologists performing the vertebroplasty is not made clear; no details are given about the number of patients they had previously treated. The incidence of osteomyelitis (3.8% at best, 30% at worst, depending on which centre was involved), despite prophylactic antibiotic therapy, is unacceptable. In the US study, injury to the thecal sac in one of 78 patients suggests incompetence. The protocol stated that cement injection was ceased if “cement reached the posterior quarter of the vertebral body or leaked into intraosseous structures”. This sometimes happens after 1 mL of cement has been injected. Experienced operators will perform various manoeuvres to ensure an adequate spread of cement occurs throughout the vertebral body. It would appear this was not done. The volumes of cement injected are not published, except an estimate of “about 3 mL”. The sham procedure was not a true placebo. Injection of local anaesthetic onto the pedicle would likely block the dorsal ramus nerve and provide partial analgesia of the fracture if the fracture extended into the pedicle. Those who perform vertebroplasty regularly see patients who are bedridden, in severe pain, intolerant of analgesics, and who have undergone various procedures including epidural injections or facet joint injections without benefit, and who then respond to vertebroplasty within 24 hours. Efforts should be aimed at refining technique and patient selection, rather than throwing out the baby with the bathwater on the basis of inappropriate studies.