Abstract
To analyse procedural details - specifically vertebral levels treated and injected polymethylmethacrylate (PMMA) volumes - of the publications by Buchbinder et al. 1 and Kallmes et al. 2 in the context of best available basic science.
Review
Two randomised controlled trials published by the New England Journal of Medicine (NEJM) in 2009 comparing vertebroplasty to sham procedures conclude vertebroplasty to be no more effective than injection of local anaesthetic. This finding contradicts previous publications showing clinical efficacy.
Neither investigation provides a breakdown of vertebral levels treated (original publication and supplementary material). Only one investigation provides information on fill volumes with average of 2.8 ml +/− 1.2 ml SD.
The available basic science indicates a minimum fill volume of 13-16% of the vertebral body volume to be necessary for a relevant biomechanical effect on restoration of vertebral strength, according to which only vertebrae of the upper to mid thoracic spine could reasonably have received a biomechanically effective fill with the declared average volume of 2.8 ml +/− 1.2 ml SD.
The available data of the NEJM publications strongly indicates that the treatment arm includes insufficiently treated patients. The technical information provided by the NEJM publications is insufficient to conclusively prove or disprove the clinical efficacy of vertebroplasty.
