Background/Purpose: We previously reported the results of a randomized participant and outcome assessor blinded controlled trial that found no beneficial effect of vertebroplasty (VP) over placebo for people with acute osteoporotic fractures up to 24 months and no between‐group differences in incident clinical vertebral fractures. A secondary aim was to determine the effect of VP on the risk of further radiologically apparent vertebral fracture at 12 and 24 months.

Methods: The trial was registered (ACTRN012605000079640), and conducted between April 2004 and October 2010. Eligible participants had one or two acute osteoporotic vertebral compression fractures of at least grade 1, confirmed by history, radiograph and the presence of bone oedema. They were randomly assigned to VP (n=38) or placebo (n=40). Cement volume and leakage were recorded for the VP group during the cement injection and on imaging post-procedure.

Plain thoracolumbar radiographs were taken at baseline, 12 and 24 months. Two independent radiologists assessed these for new and progressed fractures at the same, adjacent and non-adjacent levels. Discrepancies were resolved by consensus at the completion of the review process.

A total sample of 164 participants (82/group) was needed to show a three-fold increase in the risk of further vertebral fractures at 24 months assuming a 10% event rate in the placebo group. Recruitment difficulties led to trial enrolment being terminated early after reaching sufficient numbers to address the primary efficacy outcomes but insufficient to assess the safety outcomes.

Results: Baseline characteristics were similar between the two groups (31 females in each group, mean (SD) age, median (interquartile range) duration of symptoms and one or more prior vertebral fractures was 74.2 (14.0), 9.0 (3.8 to 13.0) and 18 (47%) in the VP group, and 78.9 (9.5), 9.5 (3.0 to 17.0) and 21 (52%) in the placebo group).

At 12 and 24 months, radiographs were available for 45 (58%) and 47 (60%) participants respectively. There were no between-group differences for new or progressed fractures: 32 and 40 in the VP group after 12 and 24 months compared with 21 and 33 in the placebo group (hazard ratio (HR) 1.80, 95% confidence interval (CI) 0.08 to 3.94). Similar results were seen when considering only adjacent (HR (95% CI): 2.30 (0.57 to 9.29)), and non-adjacent (HR (95% CI): 1.45 (0.55 to 3.81) levels. In all comparisons there was a consistent trend towards higher risk of any type of fracture in the group undergoing VP.

Within the VP group, fracture risk was unrelated to total cement volume (HR (95% CI): 0.91 (0.71 to 1.17)), relative cement volume (HR (95% CI): 1.31 (0.15 to 11.48)), cement leakage (HR (95% CI): 1.20 (0.63 to 2.31)), age, sex, site of treated level, use of bisphosphonates at baseline or current bisphosphonate use, glucocorticoid use or duration of use, previous vertebral fracture or bone mineral density.

Conclusion: While our results indicate a possible increase in risk of radiologically apparent vertebral fractures following VP, we did not have sufficient power to draw definitive conclusions. Further adequately powered studies are needed to address this question.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/new-vertebral-fractures-after-vertebroplasty-two-year-results-from-a-randomised-placebo-controlled-trial/