title: The design and production of Co-Cr alloy implants with controlled surface topography by CAD-CAM method and their effects on osseointegration.
abstract: Improved fixation and increased longevity are still important performance criteria in the development of orthopaedic prostheses. The osseointegration of a series of implant designs made of conventional cobalt-chromium alloy was investigated, the shape of each implant being the critical variable. The shape was defined by computer-aided design with a view to maximising interdigitation of new bone with the implant. Two different process routes, conventional casting and selective laser sintering were employed, each process yielded implants that had identical surface topology but different microstructures. Hydroxyapatite (HA) was used to coat some samples by plasma spraying. Bone formation associated with each implant design was delineated through the administration of fluorescent vital dyes at three time points following their implantation into New Zealand white rabbits. After one month, specimens were harvested, resin embedded, serial sectioned and examined under fluorescent light microscopy. The amount of bone growth was quantified using image analysis. Plasma spray HA-coated samples promoted better osteogenesis and integration than uncoated samples. The extent of bone growth associated with identically shaped specimens fabricated by the SLS route was markedly greater, attributed to the microstructure of these implants.
authors.affiliation: UK Centre for Tissue Engineering (UKCTE), University of Liverpool, Duncan Building, Daulby Street, L69 3GA, UK. huntja@liverpool.ac.uk
authors.forename: John Alan
authors.initials: JA
authors.lastname: Hunt
authors.forename: Jill T
authors.initials: JT
authors.lastname: Callaghan
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Sutcliffe
authors.forename: Rhys H
authors.initials: RH
authors.lastname: Morgan
authors.forename: Ben
authors.initials: B
authors.lastname: Halford
authors.forename: Richard A
authors.initials: RA
authors.lastname: Black
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D018786:Bone Substitutes; D001842:Bone and Bones; D002858:Chromium Alloys / Q000737:chemistry*; D017076:Computer-Aided Design; D017886:Durapatite / Q000737:chemistry; D005456:Fluorescent Dyes / Q000494:pharmacology; D007091:Image Processing, Computer-Assisted; D008297:Male; D016348:Osseointegration; D019736:Prostheses and Implants; D011474:Prosthesis Design / Q000295:instrumentation / Q000379:methods*; D011817:Rabbits; D013499:Surface Properties; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D002858:Chromium Alloys; D005456:Fluorescent Dyes; D017886:Durapatite