Aims: To determine the relationship between the percentage of polymethylmethacrylate cement þll of osteoporotic vertebral bodies during percutaneous vertebroplasty and the percentage restoration of strength and stiffness. Methods: The volume of 120 vertebral bodies (T6-L5) harvested from 10 osteoporotic spines female cadavers was determined by Archimedes displacement. Compression fractures were experimentally created to determine the initial strength and stiffness. The vertebral bodies were stabilized using bipedicular injections of between 2-8mL of cement and then recompressed and post treatment strength and stiffness was measured. Linear regression was used to check for the relationship between percent volume þll and percent restored stiffness and strength. Results: The correlation between percentage þll and restored strength and stiffness was weak, r2 = 0.21 and r2 = 0.27 respectively. The correlation showed that on average, a 16.2% cement þll of the VB volume was needed to restore strength and 29.8% þll was needed to restore stiffness). Conclusions: Strength and stiffness are weakly correlated with the percentage þll volume of cement injected during vertebroplasty.