Biomechanical evaluation of three surgical scenarios of posterior lumbar interbody fusion by finite element analysis

State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun, People's Republic of China.
BioMedical Engineering OnLine (Impact Factor: 1.43). 06/2012; 11:31. DOI: 10.1186/1475-925X-11-31
Source: PubMed


For the treatment of low back pain, the following three scenarios of posterior lumbar interbody fusion (PLIF) were usually used, i.e., PLIF procedure with autogenous iliac bone (PAIB model), PLIF with cages made of PEEK (PCP model) or titanium (Ti) (PCT model) materiel. But the benefits or adverse effects among the three surgical scenarios were still not fully understood.
Finite element analysis (FEA), as an efficient tool for the analysis of lumbar diseases, was used to establish a three-dimensional nonlinear L1-S1 FE model (intact model) with the ligaments of solid elements. Then it was modified to simulate the three scenarios of PLIF. 10 Nm moments with 400 N preload were applied to the upper L1 vertebral body under the loading conditions of extension, flexion, lateral bending and torsion, respectively.
Different mechanical parameters were calculated to evaluate the differences among the three surgical models. The lowest stresses on the bone grafts and the greatest stresses on endplate were found in the PCT model. The PCP model obtained considerable stresses on the bone grafts and less stresses on ligaments. But the changes of stresses on the adjacent discs and endplate were minimal in the PAIB model.
The PCT model was inferior to the other two models. Both the PCP and PAIB models had their own relative merits. The findings provide theoretical basis for the choice of a suitable surgical scenario for different patients.

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Available from: Liya Wang, Oct 30, 2014
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    • "In addition, the application of FEA in objects with pathological changes has resulted in difficulties with tissue-margin discrimination for irregular pathological structures, thereby affecting the accuracy and efficiency of the traditional method. Manual discrimination of the contour of delicate osteoporotic structures and irregular osteophytes in elderly patients with typical pathological changes is ambiguous and time-consuming (22). Subsequently, miscutting of vertebral bone tissues often occurs (23). "
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