EVALUATION OF VARIOUS DEVICE DESIGNS FOR POSTERIOR LUMBAR INTERBODY FUSION SURGERY USING A T10–S1 MULTILEVEL SPINE MODEL

Abstract

A spinal fusion surgery has been the gold standard treatment for treating lumbar degenerative disc disease. Many clinical studies have demonstrated that adjacent segment degeneration was observed in patients over time. Different types of stabilization systems have been investigated using numerical approaches. However, numerical models developed in the past were simplified to reduce computational time. Additionally, it is quite difficult to compare different stabilization systems in clinical application due to variation in bone anatomy and density. The aim of this study is to evaluate and compare the biomechanical performances of different stabilization systems using a more realistic spine model. In this study, three-dimensional finite element models of the intact, injured and treated T10–S1 multilevel spines are developed. The intersegmental rotation, the maximum disc stress and the maximum implant stress are calculated. The results showed that the pedicle screw–rod system can provide better fixation stability and lower implant stress. The Coflex system (CFS) has an advantage on reducing the risk of adjacent segment degeneration. This study could provide useful information to surgeons understanding the effects of different stabilization systems on the biomechanical performances for the posterior lumbar interbody fusion surgery.