Bone quality deterioration is accompanied by mesenchymal stem cell defects in osteoporosis patients undergoing spinal fusion

Abstract

As the elderly population grows, the number of osteoporosis (OP) patients undergoing spinal fusion has been increasing, and they often require more postoperative revision. Our research aims to examine the health status of autologous bone grafts and bone marrow mesenchymal stem cells (BMSCs) in patients with OP, in order to prevent postoperative complications. Cancellous bone specimens from spinous processes were obtained from 54 aging patients (Osteoporosis (OP) and non-OP groups, n=27 for each) during lumbar fusion surgery. In addition, bone marrow mesenchymal stem cells (BMSCs) were harvested from vertebral bodies of 28 of the 54 patients (20 postmenopausal women and 8 men older than 50 years-of-age). Bone microstructure was measured using micro-CT. BMSC number, proliferation capacity, and osteogenic and adipogenic potential were evaluated in vitro. Compared to non-OP subjects, less bone volume fraction (BV/TV), trabecular thickness (Tb.Th), and higher structure model indices (SMI) were noted in the OP group. In addition, decreased BMSCs and proliferative capacity and osteogenic potential occurred in the OP group. The adipogenic potential of BMSCs was not clear. Total BMD of the lumbar spine was positively correlated with proliferative capacity and the osteogenic differentiation potential of BMSCs. In summary, Bone quality deterioration is accompanied by quantitative and qualitative defects of BMSCs in OP patients undergoing bone fusion. Total BMD of the lumbar spine (L1–L4) as measured using DXA may predict BMSC proliferative capacity and osteogenic potential.