Material properties of various cements for use with vertebroplasty

The purpose of the current study was to measure the material properties of various cements prepared per manufacturers' recommendations and of cements modified according to compositions developed by clinicians with experience performing vertebroplasty. Cement was prepared, cast to form cylindrical specimens, and tested in compression. The optical density of specimens from the various cement preparations was measured. Batches of Simplex P and Cranioplastic cement were also prepared with increased concentrations of BaSO₄ (20% and 30%; and 10%, 20% and 30%, respectively) to evaluate the effect of additional BaSO₄. Compressive modulus values for polymethylmethacrylate cements ranged from 2–2.7 GPa; some differences were significant (p<0.05). Compared with polymethylmethacrylate cements, Orthocomp exhibited almost twice the compressive modulus and 2–3 times the strength values. Increasing the BaSO₄ concentration in Simplex P and Cranioplastic significantly (p<0.05) affected their material properties; however, it is unknown if these changes in material properties are clinically important. Optical density increased as a function of concentration of the opacifying agent added. The current study provides clinicians with information on changes in the material properties of bone cements when the compositions are altered in a manner consistent with the practice of vertebroplasty.