Lumbar interbody fusion using autologous bone marrow mesenchymal stem cell-calcium phosphate ceramic composite in rhesus monkey / 中华外科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To determine the osteogenic capacity of autologous bone marrow mesenchymal stem cells (BMSCs)-calcium phosphate ceramic composites in vitro and implanted as a bone graft substitute for lumbar anterior interbody fusion in rhesus monkeys.</p><p><b>METHODS</b>From March 2003 to April 2005, 9 adult rhesus monkeys underwent lumbar L(3 - 4) and L(5 - 6) discectomy and interbody fusion via an anterior retroperitoneal approach. Two fusion sites in each animal were randomly assigned to two of three treatments autogenous tricortical iliac crest bone graft (autograft group, n = 6) or cell-free ceramic graft (ceramic group, n = 6) or BMSCs-ceramic composite graft (BMSCs group, n = 6). Autologous BMSCs were culture-expanded and stimulated with osteogenic supplement. The cell-ceramic composites were constructed in a rotary dynamic cell culture system. The spinal fusion segments were evaluated by radiography, biomechanical testing, histologic analysis and histomorphometric analysis at 3 months post-surgery.</p><p><b>RESULTS</b>Biomechanical testing showed that spinal segments from the autograft group and the BMSCs-ceramic group were statistically and significantly stiffer than the cell-free ceramic group. The BMSCs-ceramic group and the autograft group showed equivalent biomechanical stiffness by statistical analysis. Histologically, both the autograft group and the BMSCs-ceramic group achieved osseous union, but the cell-free ceramic group had a fibrous union. Quantitative histologic analysis showed that the amount of bone formation was significantly greater in the autograft group and the BMSCs-ceramic group compared with the cell-free ceramic group. However, the amount of ceramic residue was significantly greater in the cell-free ceramic group versus the BMSCs-ceramic group.</p><p><b>CONCLUSIONS</b>The results indicate that BMSC-ceramic composites can enhance bone regeneration and achieve osseous spinal fusion 3 months after the implantation in rhesus monkey interbody fusion model. Cell-free ceramics has an unsatisfactory efficacy in spinal fusion due to its tense fibrous fusion.</p>