A novel injectable bioactive bone cement for spinal surgery: a developmental and preclinical study

The injection of bone cement by minimally invasive techniques for the treat ment of vertebral body fractures or for stabilization of an osteoporotic ve rtebral body is regarded as promising in spinal surgery. The purpose of thi s study was to develop a novel injectable bioactive bone cement to address such concerns. The cement was composed mainly of strontium-containing hydro xyapatite (Sr-HA) filler and Bisphenol A Diglycidylether Dimethacrylate (D- GMA) resin. The Sr-HA filler was prepared by precipitation and calcination, then analyzed with Fourier transform infrared (FTIR) spectra and X-ray dif fraction (XRD) patterns. Samples of strontium-containing hydroxyapatite cem ent (SrHAC) were formed by a combination of powder filler and resin matrix, with the setting time and peak temperature recorded. Cell relative growth rate (RGR), Tetrazolium bromide (MTT), and haemolysis tests were used to de tect initial in vitro biocompatibility of the new cement, in vitro spinal b iomechanical testing and morphological observation after bone cement inject ion were performed on pig spines. Results indicate that the setting time an d peak temperature of the cement was 15 min and 55 degrees C, respectively. Cytotoxicity of the cement was class 1 (no cytotoxicity) and haemolysis wa s 1% (no haemolysis). Stiffness after cement injection and fatigue loading were 112% and 95% of the intact bone, respectively, which is similar to tha t of natural bone. Radiopacity of SrHAC allowed easy radiographic imaging. The use of SrHAC cement is, thus, promising in spinal surgery. (C) 2000 Joh n Wiley & Sons, Inc.