title: Free form fabricated features on CoCr implants with and without hydroxyapatite coating in vivo: a comparative study of bone contact and bone growth induction.
abstract: The current study evaluates the in vivo response to free form fabricated cobalt chromium (CoCr) implants with and without hydroxyapatite (HA) plasma sprayed coatings. The free form fabrication method allowed for integration of complicated pyramidal surface structures on the cylindrical implant. Implants were press fit into the tibial metaphysis of nine New Zealand white rabbits. Animals were sacrificed and implants were removed and embedded. Histological analysis, histomorphometry and electron microscopy studies were performed. Focused ion beam was used to prepare thin sections for high-resolution transmission electron microscopy examination. The fabricated features allowed for effective bone in-growth and firm fixation after 6 weeks. Transmission electron microscopy investigations revealed intimate bone-implant integration at the nanometre scale for the HA coated samples. In addition, histomorphometry revealed a significantly higher bone contact on HA coated implants compared to native CoCr implants. It is concluded that free form fabrication in combination with HA coating improves the early fixation in bone under experimental conditions.
authors.affiliation: The Ångström Laboratory, Department of Engineering Sciences, Uppsala University, Box 534, 751 21 Uppsala, Sweden. kathryn.grandfield@angstrom.uu.se
authors.forename: Kathryn
authors.initials: K
authors.lastname: Grandfield
authors.forename: Anders
authors.initials: A
authors.lastname: Palmquist
authors.forename: Stéphane
authors.initials: S
authors.lastname: Gonçalves
authors.forename: Andy
authors.initials: A
authors.lastname: Taylor
authors.forename: Mark
authors.initials: M
authors.lastname: Taylor
authors.forename: Lena
authors.initials: L
authors.lastname: Emanuelsson
authors.forename: Peter
authors.initials: P
authors.lastname: Thomsen
authors.forename: Håkan
authors.initials: H
authors.lastname: Engqvist
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000378:metabolism / Q000648:ultrastructure; D002857:Chromium / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D005260:Female; D007477:Ions; D008422:Materials Testing; D046529:Microscopy, Electron, Transmission / Q000379:methods; D016348:Osseointegration; D019736:Prostheses and Implants; D011817:Rabbits; D013499:Surface Properties; D013977:Tibia / Q000473:pathology* / Q000648:ultrastructure; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D007477:Ions; D002857:Chromium; D003035:Cobalt; D017886:Durapatite; D014025:Titanium