Affiliations: Orthopaedic Biomechanics Laboratory, Institute of Biomedical Engineering, National Yang‐Ming University, Taipei, Taiwan | Department of Orthopaedic Surgery, Veteran General Hospital‐Taipei, Taipei, Taiwan
Note: [] Corresponding author: Cheng‐Kung Cheng, Ph.D., Institute of Biomedical Engineering, National Yang‐Ming University, 155 Sec. 2, Li‐Nung St., Taipei, Taiwan. Tel.: 886 2 28267020; Fax: 886 2 28202519; E‐mail: ckcheng@bme.ym.edu.tw.
Abstract: The anterior lumbar interbody fusion is the common procedure in the management of the degenerated disc in the lumbar spine, but the biomechanical behavior of the fused segment would be changed because of the implantation of bone graft at the different locations. To investigate the biomechanical alteration, the study applied the finite element model to undergo the stress analysis. A three‐dimensional finite element model of the lumbar spine was established, and modified to the three fusion models consisted of the bone graft at the anterior site, the middle site and the posterior site, respectively. The 12 N m flexion and the 10 N m torsion with pre‐load 150 N were imposed on the L1 vertebral body. The results of the finite element model indicated that placing bone graft at anterior site could effectively resist flexion moment, and decreased the tensile force of the posterior ligaments about 15% above. Placing bone graft at posterior site could resist torsional moment, and also led to none of contact force of the facet joint in the fused segment. However, wherever the bone grafts were placed, stress slightly increased on the disc adjacent to interbody fusion about 5% below.
Keywords: Finite element analysis, lumbar spine, bone graft
