The initial findings of the two randomized, controlled studies suggest that vertebroplasty, a procedure commonly used to treat painful, osteoporotic vertebral compression fractures in which cement is used to fill the cracks, is no more effective than a placebo procedure at reducing pain.
The NASS states that the two studies should be scrutinized, as the findings have created “surprise and disbelief” for spine surgeons who have personally seen positive outcomes in patients undergoing the procedure.
In scrutinizing the two studies, the NASS highlights various potential factors in patient selection that may have yielded neutral results. Specifically, the NASS discussed four issues within the patient selection process:
1. Fracture acuity — The NEJM studies defined acute fractures as less than one year old, while most NASS members would define an acute fracture as no more than six weeks old. Pain associated with fractures reduces over time, so it would be “reasonable to assume that sometime between three months and six months fracture pain reduced to a level equivalent to the pain reduction that might be observed with vertebroplasty,” according to the release.
2. Enrollment — Informed consent required researchers to inform patients that they might receive a placebo as opposed to the actual vertebroplasty procedure. As a result, the NASS reasons that patients with the most severe pain would be less likely to enroll in the study in order to proceed with vertebroplasty.
3. Control group — In both NEJM studies, NASS argues that the control groups underwent alternative interventions, rather than a true placebo procedures. The control group members received an injection of an anesthetic into the facet capsule or periosteum, which may have provided some pain relief.
4. Outcomes — The NASS argues that, in both studies, measures of pain before and following the procedure did not attempt to determine if reported pain indeed originated from the osteoporotic fracture.
Read the release on the NASS’s response to recent vertebroplasty studies (pdf).
