Turkish Neurosurgery 2016 , Vol 26 , Num 3
Construction of Finite Element Model for an Artificial Atlanto-Odontoid Joint Replacement and Analysis of Its Biomechanical Properties
Yong HU1, Wei-xin DONG1, Shannon HANN2, Zhen-shan YUAN1, Xiao-yang SUN1, Hui XIE1, Meichao ZHANG3
1The Affiliated Ningbo No.6 Hospital of Medical School of Ningbo University, Department of Spinal Surgery, Ningbo, Zhejiang Province, China
2Thomas Jefferson University & Rothman Institute, Department of Orthopaedic Surgery, Philadelphia, Pennsylvania, USA
3Southern Medical University, Department of Medical Biomechanics Research, Guangzhou, Guangzhou Province, China
DOI : 10.5137/1019-5149.JTN.12681-14.0 AIM: To investigate the stress distribution on artificial atlantoaxial-odontoid joint (AAOJ) components during flexion, extension, lateral bending and rotation of AAOJ model constructed with the finite element (FE) method.

MATERIAL and METHODS: Human cadaver specimens of normal AAOJ were CT scanned with 1 mm -thickness and transferred into Mimics software to reconstruct the three-dimensional models of AAOJ. These data were imported into Freeform software to place a AAOJ into a atlantoaxial model. With Ansys software, a geometric model of AAOJ was built. Perpendicular downward pressure of 40 N was applied to simulate gravity of a skull, then 1.53 N• m torque was exerted separately to simulate the range of motion of the model.

RESULTS: An FE model of atlantoaxial joint after AAOJ replacement was constructed with a total of 103 053 units and 26 324 nodes. In flexion, extension, right lateral bending and right rotation, the AAOJ displacement was 1.109 mm, 3.31 mm, 0.528 mm, and 9.678 mm, respectively, and the range of motion was 1.6°, 5.1°, 4.6° and 22°.

CONCLUSION: During all ROM, stress distribution of atlas-axis changed after AAOJ replacement indicating that AAOJ can offload stress. The stress distribution in the AAOJ can be successfully analyzed with the FE method. Keywords : Biomechanics, Finite element method, Atlanto-odontoid joint, Atlanto-axial joint, Arthroplasty

Corresponding author : Yong Hu, huyong610@163.com