Modulation of allograft incorporation by continuous infusion of growth factors over a prolonged duration in vivo.
Morselized cancellous allograft bone is frequently used in the reconstruction of bone defects in cases of revision total joint replacement, trauma, spine fusion and treated infection. However, the initial lack of viable bone cells in morselized allograft bone significantly slows the process of graft incorporation compared to autograft bone. This study examined the effects of prolonged local infusion of the growth factors bone morphogenic protein-7 (BMP-7 or OP-1) and fibroblast growth factor-2 (FGF-2 or basic FGF) in the process of allograft incorporation using a rabbit tibial chamber model. New bone formation was evaluated by two indices, the activity of alkaline phosphatase and the level of birefringence. The markers of osteoclast-like cells were also measured. Without the infusion of the growth factors, lower levels of new bone formation were observed in the allograft group, compared to the autograft group. Infusion of growth factors FGF-2 and OP-1, singly or in combination, for 4 weeks, diminished this difference. The numbers of osteoclast-like cells were much higher in the allograft group before the growth factors were delivered. The infusion of FGF, singly, diminished this difference. However, the infusion of OP-1 or the combination of FGF and OP-1 did not decrease the number of osteoclast-like cells to a level comparable to autograft only. Local infusion of growth factors appears to be a useful adjunct to promote the incorporation of allograft bone in vivo.
Ma
Ting
T
The Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, CA 94305-5326, USA.
Gutnick
Jesse
J
Salazar
Brent
B
Larsen
Meegan D
MD
Suenaga
Eiji
E
Zilber
Sebastien
S
Huang
Zhinong
Z
Huddleston
James
J
Smith
R Lane
RL
Goodman
Stuart
S
D000818:Animals; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage*; D016025:Bone Transplantation; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage*; D006085:Graft Survival / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology*; D011817:Rabbits; D016212:Transforming Growth Factor beta / Q000008:administration & dosage*; D014184:Transplantation, Homologous
D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; D016212:Transforming Growth Factor beta; D016222:Fibroblast Growth Factor 2