Numerical Evaluation of Spinal Stability after Posterior Spinal Fusion with Various Fixation Segments and Screw Types in Patients with Osteoporotic Thoracolumbar Burst Fracture Using Finite Element Analysis

Abstract

The aim of this study was to analyze the spinal stability and safety after posterior spinal fusion with various fixation segments and screw types in patients with an osteoporotic thoracolumbar burst fracture based on finite element analysis (FEA). To realize various osteoporotic vertebral fracture conditions on T12, seven cases of Young’s modulus, namely 0%, 1%, 5%, 10%, 25%, 50%, and 100% of the Young’s modulus, for vertebral bones under intact conditions were considered. Four types of fixation for thoracolumbar fracture on T12 (fixed with T11-L1, T10-T11-L1, T11-L1-L2, and T10-T11-L1-L2) were applied to the thoracolumbar fusion model. The following screw types were considered: pedicle screw (PS) and cortical screw (CS). Using FEA, four motions were performed on the fixed spine, and the stress applied to the screw, peri-implant bone (PIB), and intervertebral disc (IVD) and the range of motion (ROM) were calculated. The lowest ROM calculated corresponded to the T10-T11-L1-L2 model, while the closest to the intact situation was achieved in the T11-L1-L2 fixation model using PS. The lowest stress in the screw and PB was detected in the T10-T11-L1-L2 fixation model.

Stress Distribution on Spinal Cord According to Type of Laminectomy for Large Focal Cervical Ossification of Posterior Longitudinal Ligament Based on Finite Element Method

“…Generally, the cervical spine comprises various hard/soft tissues. To construct a standardized model, we developed a cervical spine model with an average lordotic value based on clinical knowledge and clinical paper data [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. The intact cervical spine model consists of the cortical bone, cancellous bone, intervertebral disc (IVD), anterior longitudinal ligament (ALL), posterior longitudinal ligament (PLL), capsular ligament (CL), ligamentum flavum (LF), interspinous ligament (ISL), supraspinous ligament (SSL), and spinal cord [ Figure 1 ].…”

Spinal stability analysis of lumbar interbody fusion according to pelvic type and cage angle based on simplified spinal model with various pelvic indices

“…The pedicle screw used for spinal fixation was 6.5 mm in diameter, the length of the spindle rod was designed to fit the length of each fixed segment, and the Φ6 titanium rod commonly used for spinal surgery was applied to reflect material properties (Jindal et al, 2012;Kim et al, 2021). The vertebrae and pedicle screws were held in a bonded condition, and were assumed to be completely immobilized.…”

A novel in silico Nuss procedure for pectus excavatum patients

“…The accuracy and similarity of the in silico Nuss procedure and actual surgery can be quantitatively elucidated through this process. On the other hand, in silico surgery simulation through FEA is extensively studied not only on the chest wall, but also on the spine, joints, blood vessels, and lungs, thus securing considerable reliability [19][20][21][22][23].…”