高强度可注射复合磷酸钙骨水泥性能表征及其在椎体后凸成形术.ppt

高强度、可注射复合磷酸钙骨水 泥的性能表征及其在椎体后凸成 形术  Outlines ◆ Backgrounds Materials Methods ◆ Results& Discussion ◆conc| usIons  Backgrounds Vertebral body compression fractures (VCFS Percutaneou  Backgrounds Basic properties of calcium phosphate cement(CPc) Similar chemistry to natural bone minera Self-setting through a low exothermic reaction in aqueous environment Excellent biocom Bio-degradability, High moldability Disadvantages and problems: i Disintegrate/collapse in blood or body fluids Low compressive strength and high brittleness r Poor injectability Liquid-solid phase separation  Backgrounds The advantages of starch Biocompatible and biodegradable Biomimetic design of bone glue High compressive strength Necessity of radiopaque Monitor the surgical process Objectives: A new injectable, biomechanically robust, biodegradable, radiopacity and osseointegrative bone cement to replace PMMA in vivo for percutaneous kyphoplasty [1] Biomatertials 20(1999)393. [2] Key Engineering Matenals, 330(2007)8  Materials and methods Materials a-Tricalcium phosphate(a-TCP, Dingan) Dicalcium phosphate dihydrate(CaHPO4 2H2O, DCPD, Sigma) Barium sulfate(BaSO4, Sigma Sodium hydrogen phosphate(Na HPO4, sigma-Aldrich) · Modified starch PMMA(Mendec Spine: Tecres s sommacampagna, Italy) Compositions of cements Solid phases wt%) Types of cement a-TCP DCPD BaSo4 Starch CPS 0. 25M Na2HPO4 20 PMMA [CH2 C(CH3)(COOCH3)]n MMA  Materials and methods Characterization of composites Mechanical strength Uniaxial compressive test nitial and final setting times Measured by the vicat apparatus Injectability and collapsibility Paste injected to DI water at less than the pushout force of 50 N Microstructure The fracture surface was examined by scanning electron microscopy(SEM). Phase analysis X-ray diffraction(XRD) was performed at diffraction angles 20 from 10 to 60 and a step-scan mode of 2 per minute  Materials and methods Characterization of cPB