Understanding the choice of control group: A systematic review of vertebroplasty trials for osteoporotic vertebral compression fractures

Objectives: To better understand the choice of the comparator intervention in the design of clinical trials and its impact on the meaning of results we review randomized trials on vertebroplasty.

Methods: We conducted a systematic and narrative review of all randomized trials on vertebroplasty. Trials are categorized according to the comparator intervention (non-surgical management, placebo/sham vertebroplasty, and kyphoplasty).

Results: All trials were too small to show a difference in objective clinical outcomes, and 20 of 23 RCTs used mean pain scores to compare interventions. Most trials comparing vertebroplasty with non-surgical management concluded that vertebroplasty was superior. Trials comparing kyphoplasty with vertebroplasty showed similar results for both interventions. However, 4 of 5 trials comparing vertebroplasty with placebo surgery failed to show a significant difference between groups.

Conclusion: The clinical results of an intervention cannot be interpreted without a comparison that involves a control group. The choice of comparator intervention can change the meaning of the trial. A large pragmatic trial, using hard clinical outcomes such as morbidity and mortality as a primary outcome measure, would be needed to assess the potential clinical benefits of vertebroplasty.