title: Early bone growth on the surface of titanium implants in rat femur is enhanced by an amorphous diamond coating.
abstract: OBJECTIVE
  Amorphous diamond (AD) is a durable and compatible biomaterial for joint prostheses. Knowledge regarding bone growth on AD-coated implants and their early-stage osseointegration is poor. We investigated bone growth on AD-coated cementless intramedullary implants implanted in rats. Titanium was chosen as a reference due to its well-known performance.
  
  
  METHODS
  We placed AD-coated and non-coated titanium implants (R(a) ≈ 0.2 μm) into the femoral bone marrow of 25 rats. The animals were divided in 2 groups according to implant coating and they were killed after 4 or 12 weeks. The osseointegration of the implants was examined from hard tissue specimens by measuring the new bone formation on their surface.
  
  
  RESULTS
  4 weeks after the operation, the thickness of new bone in the AD-coated group was greater than that in the non-coated group (15.3 (SD 7.1) μm vs. 7.6 (SD 6.0) μm). 12 weeks after the operation, the thickness of new bone was similar in the non-coated group and in the AD-coated group.
  
  
  CONCLUSIONS
  We conclude that AD coating of femoral implants can enhance bone ongrowth in rats in the acute, early stage after the operation and might be an improvement over earlier coatings.
authors.affiliation: Department of Orthopedics, Bone and Cartilage Research Center, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Jarkko J P
authors.initials: JJ
authors.lastname: Jaatinen
authors.forename: Rami K
authors.initials: RK
authors.lastname: Korhonen
authors.forename: Alpo
authors.initials: A
authors.lastname: Pelttari
authors.forename: Heikki J
authors.initials: HJ
authors.lastname: Helminen
authors.forename: Hannu
authors.initials: H
authors.lastname: Korhonen
authors.forename: Reijo
authors.initials: R
authors.lastname: Lappalainen
authors.forename: Heikki
authors.initials: H
authors.lastname: Kröger
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D020099:Coated Materials, Biocompatible; D018130:Diamond; D005269:Femur / Q000502:physiology; D020007:Implants, Experimental; D016348:Osseointegration / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D018130:Diamond; D014025:Titanium