Abstract:

BACKGROUND: Our previous study confirmed that the osteogenesis of the composite bone (bone morphogenetic protein-2/allograft) is not lower than that of the autogenous bone, and the composite bone can induce the angiogenesis, however, there is no effective approach to monitoring the degree of early angiogenesis process.
OBJECTIVE: To evaluate the dynamic process and degree of revascularization in rabbits undergoing posterolateral lumbar spinal fusion with composite bone via magnetic resonance perfusion imaging plus in situ hybridization method.
METHODS: Forty-five adult male New Zealand white rabbits were randomly divided into three groups: composite bone group, autogenous bone group and simple allograft group. The rabbits in each group undergoing intertransverse posterior lunbar interbody fusion at L4 and L5 respectively. The uncellular tissue engineering bone strip, self-iliac bar and simple allogeneic iliac bar were implanted into every group respectively. At 14, 28 and 42 days after surgery, the imaging data was obtained by MRI technology, then the fusion specimens were selected for the in situ hybridization detection.
RESULTS AND CONCLUSION: There were significant differences of magnetic resonance imaging signal intensity enhancement ratio between groups (P < 0.05), the ratio of the signal strength of composite bone group reached highest at 42 days after surgery, and there was significant difference between groups. At the 14, 28 and 42 days after surgery, the expression of vascular endothelial growth factor mRNA in situ hybridization staining positive cells in composite bone group was higher than that in the autogenous bone and allograft group (P < 0.05). It is helpful to reflect the dynamic process of vascularization of the composite bone via MRI with the characteristics of noninvasive, radiation-free, sensitive and quantitative; The establishment of blood supply of composite bone early and timely can promote the bone formation in the posterolateral lumbar spinal fusion, it may provide more choices for bone graft substitute materials.