Biomechanical analysis of the degenerative lumbar spine implanting dynamic spinal fixator

• Main Authors: Li-Ying Huang, 黃瓅瑩
• Other Authors: Chen-Sheng Chen
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/67473792758052566383

碩士 === 國立陽明大學 === 物理治療暨輔助科技學系 === 99 === The DYNESYS dynamic stabilization system is used to replace spinal fusion to treat lumbar disc degeneration. It would be allowing greater physiological function and reducing the inherent disadvantages of fusion. However, radiological signs of adjacent segment degeneration were still observed. The degenerative lumbar spine in previous finite element (FE) study is not well validated. Therefore this study aimed to construct degenerated lumbar spine model for validation. The study also compared biomechanical effect of different grades of degenerative lumbar spine with spinal fixator DYNESYS. This study implemented FE software ANSYS to create four FE models, including degenerated disc Grade 1, degenerated disc Grade 2, degenerated disc Grade 1 with DYNESYS, and degenerated disc Grade 2 with DYNESYS. A hybrid control was subjected to each FE models in flexion, extension, rotation, and lateral bending. This study have validated the degenerative disc. Range of motion of degenerated motion segment was decreased following with ascending disc degeneration, and the remarkable alteration was observed in lateral bending. After implanting the DYNESYS, the greatest reduction in ROM was occurred in flexion, and the stiffness of spinal segment at implanted level in flexion is obviously higher than that at adjacent level in other loads. In adjacent disc, there was no remarkable alteration between different grades of disc degeneration with DYNESYS. However, greater adjacent disc stress raise occurred in degenerated disc Grade 1 with DYNESYS, maximally reached to 43%. As to the facet contact force, the degenerated lumbar spine with DYNESYS have greater value in extension.