title: Osteogenicity of autologous bone transplants in the goat.
abstract: BACKGROUND
  Little is known about the specific mechanisms that make autologous graft bone (AG) superior to the current alternatives. A potential mechanism is the active bone formation by the osteoprogenitor cells within the AG. However, whether these cells survive the transplantation is questionable, especially in nonvascularized, clinically sized grafts. In the present study, we investigated the role of viability in AG implanted ectopically and orthotopically in the goat.
  
  
  METHODS
  Eight goats were operated on twice. At the first operation, pieces of vital or devitalized autologous cortical bone were implanted in the paraspinal muscles. Eight weeks later, corticocancellous plugs were taken from the femoral condyles, morselized, and reimplanted as either vital or devitalized orthotopic grafts. The goats received fluorochrome labels at 5, 7, and 9 weeks after the first operation. At 12 weeks, the goats were killed, and the samples were examined histologically.
  
  
  RESULTS
  Ectopically, new bone had formed in both the vital and devitalized grafts. In the vital grafts, all three fluorochrome labels were present, indicating an early osteogenic mechanism. Within the devitalized grafts, only the 9-week label was observed. Histomorphometry indicated significantly more new bone in the vital grafts (10.3% vs. 1.7% in the devitalized grafts, P <0.01). Orthotopically, both vital and devitalized grafts showed new bone. Again, graft viability was advantageous in terms of new bone formation (14.5% vs. 9.3%, P <0.02).
  
  
  CONCLUSIONS
  The cells inside the autologous bone transplants most likely survived transplantation and were capable of initiating and sustaining new bone formation.
authors.affiliation: Department of Orthopedics, University Medical Center Utrecht, Utrecht, The Netherlands. m.c.kruijt@chir.azu.nl
authors.forename: Moyo C
authors.initials: MC
authors.lastname: Kruyt
authors.forename: Wouter J A
authors.initials: WJ
authors.lastname: Dhert
authors.forename: Cumhur
authors.initials: C
authors.lastname: Oner
authors.forename: Clemens A
authors.initials: CA
authors.lastname: van Blitterswijk
authors.forename: Abraham J
authors.initials: AJ
authors.lastname: Verbout
authors.forename: Joost D
authors.initials: JD
authors.lastname: de Bruijn
mesh_terms: D000818:Animals; D016025:Bone Transplantation; D001842:Bone and Bones / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006041:Goats; D010012:Osteogenesis; D014182:Transplantation, Autologous; D016042:Transplantation, Heterotopic