title: Biological activity of tri-calciumphosphate/hydroxyl-apatite granules mixed with impacted morsellized bone graft. A study in rabbits.
abstract: Reconstruction of bone defects with impacted morsellized cancellous bone grafts (MCB) is a popular method. Because of a shortage of human bone, mixing with biomaterials may be attractive. Ceramics may be used as bone graft extenders. In this study, various volume mixtures of biphasic tri-calciumphosphate/hydroxyl-apatite (TCP-HA) granules (1.5-2 mm) with MCB were examined in a non-loaded defect model in rabbits. Direct post-operatively, many 10-150 microm TCP-HA particles were present due to impaction. Irrespective to the group, after 8 weeks, virtually all MCB was resorbed and most TCP-HA granules were osseous-integrated with newly formed bone. The cross-sectional areas of TCP-HA after 8 weeks was generally smaller compared with direct post-operatively and the number of small 10-150 microm TCP-HA particles seemed reduced. Macrophages and giant cells were sparse after 8 weeks. In conclusion, the osteoconductivity of various mixtures of MCB and TCP-HA granules is not dependent on the ratio of TCP-HA over MCB. The reduced number of the 10-150microm TCP-HA particles after 8 weeks, may suggest that a cellular mediated resorption process of TCP-HA granules took place. Based on these favorable biological findings subsequent in-vivo experiments are warranted in load-bearing conditions to investigate whether these findings hold for joint reconstruction purposes.
authors.affiliation: Orthopedic Research Laboratory, Department of Orthopedics, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen, The Netherlands.
authors.forename: J J C
authors.initials: JJ
authors.lastname: Arts
authors.forename: L H B
authors.initials: LH
authors.lastname: Walschot
authors.forename: N
authors.initials: N
authors.lastname: Verdonschot
authors.forename: B W
authors.initials: BW
authors.lastname: Schreurs
authors.forename: P
authors.initials: P
authors.lastname: Buma
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000008:administration & dosage*; D016025:Bone Transplantation; D002130:Calcium Phosphates / Q000008:administration & dosage*; D017886:Durapatite / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration; D010316:Particle Size; D019736:Prostheses and Implants; D011475:Prosthesis Failure; D011817:Rabbits; D014184:Transplantation, Homologous
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; D017886:Durapatite; C018392:tricalcium phosphate