title: Ceramic bone graft substitute with equine bone protein extract is comparable to allograft in terms of implant fixation: a study in dogs.
abstract: OBJECTIVE
  We studied whether osseointegration and fixation of plasma-sprayed titanium implants grafted with beta-TCP granules (Ossaplast) can be improved by adding an osteogenic signal (Colloss E). The results were compared to implants grafted with fresh frozen morselized allograft with and without the Colloss E device.
  
  
  METHODS
  4 porous-coated Ti implants were placed in the proximal humeri in each of 10 dogs. All implants were surrounded by a 2.5-mm defect, which was grafted with: (A) beta-TCP, (B) beta-TCP+20 mg Colloss E, (C) allograft, or (D) allograft+20 mg Colloss E. The observation time was 4 weeks.
  
  
  RESULTS
  Mechanical testing showed that the beta-TCP group with Colloss E was twice as well fixed as the control group grafted with beta-TCP granules alone, and comparable to both allograft groups. We found that every control implant in the beta-TCP grafted group was covered by a dense fibrous membrane. No fibrous tissue was seen in the beta-TCP group augmented with Colloss. These implants were well osseointegrated, with new bone covering 10-25% of the implant surface. Both treated groups had increased graft resorption compared to their respective control groups. Colloss E had no effect on new bone formation or fibrous tissue reduction around the allografted implants.
  
  
  CONCLUSIONS
  The Colloss E device improved early osseointegration of implants grafted with beta-TCP granules and increased their mechanical implant fixation to the level of allografted implants. The experiment indicates that ceramic bone substitutes may be a viable alternative to allograft when combined with an osteogenic signal such as Colloss E.
authors.affiliation: Orthopedic Research Laboratory, Aarhus University Hospital, Denmark. baas@ki.au.dk
authors.forename: Jorgen
authors.initials: J
authors.lastname: Baas
authors.forename: Brian
authors.initials: B
authors.lastname: Elmengaard
authors.forename: Joan
authors.initials: J
authors.lastname: Bechtold
authors.forename: Xinqian
authors.initials: X
authors.lastname: Chen
authors.forename: Kjeld
authors.initials: K
authors.lastname: Søballe
mesh_terms: D000818:Animals; D018786:Bone Substitutes; D016025:Bone Transplantation / Q000379:methods; D002516:Ceramics; D004285:Dogs; D006811:Humerus / Q000473:pathology / Q000502:physiology; D020007:Implants, Experimental; D016348:Osseointegration / Q000502:physiology; D013314:Stress, Mechanical; D014025:Titanium; D014184:Transplantation, Homologous
chemical_list: D018786:Bone Substitutes; D014025:Titanium