Abstract:

BACKGROUND: Thoracolumbar burst fracture is a common injury in clinic. Inner fixation surgery through anterior and posterior approach is the commonly used method to rebuild the stability. The stress distribution has not been reported in literature.
OBJECTIVE: To investigate the stress distribution of internal fixation materials in titanium mesh reconstruction screw-rods system fixation and posterior approach screw-rods system fixation for the treatment of L₁ segment burst fracture by three-dimensional finite element analysis, and to compare the stability of these two methods.
METHODS: One healthy male volunteer was selected to establish the T₁₂-L₂ segment three-dimensional finite element model through CT scan and finite element software. The L₁ segment burst fracture was simulated on the effective finite element model to establish the anterior approach L₁ segment titanium mesh reconstruction combine screw-rods system fixation (model A) and posterior approach short segment screw-rods system fixation (model B), the load was applied on the models in order to observe the stress distribution and compare the stability.
RESULTS AND CONCLUSION: A T₁₂-L₂ segment three-dimensional finite element model was established. In the loading experiment, the stress of model A was mainly in the titanium mesh area and the stress of model B was mainly concentrated in the screw-rod junction. Both model A and model B could gain valid stability in reconstruction of L₁ segment burst fracture, and the former was better than later. Mean stress in T₁₂ plane of model A was less than that of model B, and the difference was statistically significant (P < 0.01). Titanium mesh deposition after anterior approach and screw-rod fracture after posterior approach may relate with local stress concentration. The anterior approach titanium mesh reconstruction combine screw-rods system fixation has the better stability than posterior approach screw-rods system fixation.