Finite Element Model of A-P Instrimentation in Thoracolumbar Burst Fracture.
10.4184/jkss.2006.13.3.170
- Author:
Ye Soo PARK
1
;
Yoon Hyuk KIM
;
Won Man PARK
Author Information
1. Department of Orthoapedic Surgery, Guri Hospital, Hanyang University College of Medicine, Korea.
- Publication Type:Original Article
- Keywords:
Spinal Fixation;
Finite Element Model
- MeSH:
Humans;
Spinal Fractures;
Spine
- From:Journal of Korean Society of Spine Surgery
2006;13(3):170-176
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
STUDY DESIGN: Finite element models of the thoracolumbar spine with various techniques used in spinal fractures were developed to investigate the effects of fixation techniques on spinal stiffness. OBJECTIVES: To develop finite element models of the thoracolumbar spine with various fixation techniques to compare their spinal stiffness characteristics. SUMMARY OF LITERATURE REVIEW: Various anterior and posterior instrumentation options have been applied to stabilize unstable burst fractures of the thoracolumbar spines. The biomechanical effects of different instrumentation options on spinal stability are still unknown. MATERIALS AND METHODS: The 3-D finite element model of the human thoracolumbar spine (T12-L2) was reconstructed from CT images. Various anterior and posterior instrumentation techniques, 1-rod and 2-rod anterior fixations, anterior fixations with posterior fixation, and posterior fixation only, were virtually performed in the developed model with a long cage after corpectomy. Five loading cases, axial compression, flexion, extension, lateral bending, and torsion, were applied up to 1000 N and 10 Nm, respectively. The axial displacement and the rotations of T12 with respect to L2 were measured to analyze the stiffness of the spinal segments. RESULTS: The posterior fixation technique increased the stiffness of the spine the most. The addition of an anterior rod from 1 to 2 increased the stiffness significantly without posterior fixation, but little effect was found with posterior fixation. Among all fixation techniques, the inter-segmental stiffnesses were similar to those of the intact model in torsion cases. In the other loading cases, the inter-segmental stiffnesses were much greater than those of the intact models. CONCLUSIONS: Finite element models of the thoracolumbar spine were developed with various fixation methods. The intact models were validated with in-vitro experimental tests. The posterior fixation technique had a more significant effect on spine stability than did anterior fixation. And anteroposterior fixation techniques provided increased spinal stiffness
