Selection of suitable pedicle screw for degenerated cortical and cancellous bone of human lumbar spine: A finite element study

Abstract

Pedicular arthrodesis is the traditional procedure in terms of increase in the biomechanical stability with higher fixation rate. The current work aims to identify the effect of three spinal pedicle screws considering cortical and cancellous degeneracy condition. Lumbar section L2-L3 is utilized and various load and moment conditions were applied to depict the various biomechanical parameters for selection of suitable screw. Three dimensional model is considered in finite element analysis to identify the various responses of pedicle screw at bone screw juncture. Computed tomography (CT) images of a healthy male were considered to generate the finite element vertebral model. Generated intact model was further utilized to develop the other implanted models of degenerated cortical and cancellous bone models. The three fused instrumented models with different cortical and cancellous degeneracy conditions were analyzed in finite element analysis. The results were obtained as stress pattern at bone screw boundary and intervertebral disc stress. FE simulated results represents significant changes in the von Mises stress due to various load and moment conditions on degenerated bones during different body movement conditions. Results have shown that among all pedicle screws, the 6.0 mm diameter screw reflects very less stress values at the juncture. Multiple results on biomechanical aspects obtained during the FE study can be considered to design a new stabilization device and may be helpful to plan surgery of critical sections.

A novel bone cement injector augments Chinese osteoporotic lumbar pedicle screw channel: a biomechanical investigation

“…Several studies have reported approaches to improve the stability of pedicle screws, including enlarging the diameter of pedicle screws [ 20 ], modifying the screw thread [ 21 ], performing injectable pedicle screw [ 22 ], proper pedicle screw selection [ 23 ], fused lumbar spine [ 24 ], and directly injecting bone cement into the pilot hole [ 25 ]. A biomechanical study had proved that solid screws with retrograde cement pre-filling was capable of achieving improved initial fixation strength as compared to cannulated screws with cement injection via perforation [ 26 ].…”

Finite Element Method for the Evaluation of the Human Spine: A Literature Overview

“…As a result, it can be concluded that a precise model of degenerated facet joints is essential for predicting future changes in facet joint loads following disc degeneration. FEM models have also been performed for the biomechanical investigation of various methods for managing multilevel myelopathy of the cervical spine [47][48][49][50][51]. For instance, in a recent study, an intact C2-C7 spine model was generated.…”

Comparison of novel stabilisation device with various stabilisation approaches: A finite element based biomechanical analysis

“…21 Previous studies considering finite element analysis (FEA) have also suggested various instrumentation methods to achieve stability to degenerated segments. 22,23 Moreover, researchers have also proposed different stabilisation systems to replicate and simulate an actual spinal segment for better treatment solutions. [24][25][26][27][28][29] Accordingly, it is essential to study the range of motion and load study for any fixation device aiming for spinal stability.…”