Collagen/β-TCP composite as a bone-graft substitute for posterior spinal fusion in rabbit model: a comparison study.

beta-TCP bioceramic, as a kind of biocompatible and biodegradable artificial bone scaffolds, is increasingly used to supplement lamina autografts when performing instrumented or noninstrumented spinal fusion, clinically, although solid fusion is not always achieved. The addition of collagen to beta-TCP appears to be a potential strategy to improve bone regeneration, thereby enhancing the rate of spinal fusion. This study aimed to compare the fusion in collagen/beta-TCP composite, beta TCP and autologous bone in a posterior spinal fusion model. The fusion grade evaluated radiography was greater in the collagen/beta-TCP group than in the beta-TCP group (p<0.05). Stiffness and yield strength of the fused segments in collagen/beta-TCP group were comparable to that in autogenous bone group. Histological analysis revealed that the proportion of new bone formation in collagen/beta-TCP group were significantly greater than in beta-TCP group (p<0.05). In addition, bone deposition rate in the collagen/beta-TCP group was greater than in the beta-TCP group (p<0.05) and comparable to that in the autogenous bone group. Wetherefore concluded that collagen/beta-TCP is superior to beta-TCP alone in facilitating posterior spinal fusion. The addition of collagen to beta-TCP represents a simple strategy that couples the osteogenic effect, providing a promising alternative to autologous bone in the clinical treatment of spinal disorders.