title: The use of a bioresorbable nano-crystalline hydroxyapatite paste in acetabular bone impaction grafting.
abstract: Calcium phosphates such as TCP-HA granules are considered promising bone graft substitutes. In the future, they may completely replace allograft bone for impaction grafting procedures. Mechanically, acetabular reconstructions with TCP-HA granules show high stability, however this is partly caused by excessive cement penetration, which is unfavourable from a biological perspective. It has been hypothesised that mixtures of morselised cancellous bone grafts (MCB) and/or TCP-HA granules with a nano-crystalline hydroxyapatite paste (Ostim) may reduce cement penetration while maintaining adequate implant stability and biocompatibility of the graft mixture. To investigate this hypothesis, destructive lever-out tests and in vivo animal test were performed with various combinations of materials. Mechanically, the addition of 10% Ostim to mixtures of MCB and/or TCP-HA granules reduced cement penetration and resulted in a mechanical stability comparable to pure allograft (the current gold standard). Biologically, the application of Ostim with MCB or TCP-HA granules did not hamper the biocompatibility of the materials. Ostim was mostly osseous-integrated with MCB or TCP-HA granules after 8 weeks. Also, non-osseous-integrated Ostim remnants were observed. In tartrate resistant acid phosphatase stained sections, these few non-osseous integrated Ostim remnants were actively being resorbed by osteoclasts. In conclusion, Ostim HA-paste could be a valuable addition when TCP-HA ceramic granules are being used for acetabular bone impaction grafting procedures.
authors.affiliation: Orthopaedic Research Laboratory, Department Orthopaedics, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: J J
authors.initials: JJ
authors.lastname: Chris Arts
authors.forename: Nico
authors.initials: N
authors.lastname: Verdonschot
authors.forename: Berend W
authors.initials: BW
authors.lastname: Schreurs
authors.forename: Pieter
authors.initials: P
authors.lastname: Buma
mesh_terms: D020341:Absorbable Implants; D000077:Acetabulum / Q000473:pathology* / Q000601:surgery*; D000818:Animals; D001843:Bone Cements / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry* / Q000627:therapeutic use*; D003460:Crystallization / Q000379:methods; D017886:Durapatite / Q000737:chemistry*; D005260:Female; D005264:Femoral Fractures / Q000473:pathology / Q000628:therapy; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D051381:Rats
chemical_list: D001843:Bone Cements; D018786:Bone Substitutes; D017886:Durapatite