A 1-Year Study of Osteoinduction in Hydroxyapatite-Derived Biomaterials in an Adult Sheep Model: Part II. Bioengineering Implants to Optimize Bone Replacement in Reconstruction of Cranial Defects

摘要: The present study investigated hydroxyapatite biomaterials implanted in critical-size defects the calvaria of adult sheep to determine optimal bioengineering composites facilitate bone ingrowth into these materials. Five calvarial measuring 16.8 mm diameter were made each 10 sheep. Three filled with cement paste and beta-tricalcium phosphate as follows: (1) 100 percent hydroxyapatite-cement paste, (2) 60 (3) 20 paste. One defect was a ceramic composite containing hydroxyapatite-ceramic, fifth remained unfilled. year after implantation, volume all determined by computed tomography, porosity replacement using backscatter electron microscopy. Computed tomography-based volumetric assessment 1 implantation demonstrated that none unfilled cranial closed over 1-year period, confirming defects. There significant increase both implants (p < 0.01). no change remaining biomaterials. Analysis specimens microscopy mean 4.8 +/- 1.4 (mean SEM) 11.2 2.3 28.5 4.5 an inverse correlation between concentration amount for tested Bone hydroxyapatite-ceramic (13.6 2.0 percent) not significantly different from Of note is contained macropores (200 300 microm) did size period. All initially micropores (3 5 nm), which unchanged Cement increased tricalcium corresponding following resorption component. occurred within implants. In conclusion, there pure (Bone Source, Stryker-Leibinger Inc., Dallas, Texas) study. introduction biomaterial can optimize reconstruction calvaria. This increasing composition rapidly resorbing component such phosphate.