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題名 Influence of Dynesys system screw profile on adjacent segment and screw 作者 施世亮
Liu, Chien-Lin ; Zhong, Zheng-Cheng ; Shih, Shih-Liang ; Huang, Chinghua ; Lee, Yong-Eng ; Chen, Chen-Sheng貢獻者 神科所 日期 2010-08 上傳時間 19-Nov-2014 10:41:46 (UTC+8) 摘要 Study Design: Displacement-controlled finite element analysis was used to evaluate the mechanical behavior of the lumbar spine after insertion of the Dynesys dynamic stabilization system. Objective: This study aimed to investigate whether different depths of screw placement of Dynesys would affect load sharing of screw, range of motion (ROM), annulus stress, and facet contact force. Summary of Background Data: In clinical follow-up, a high rate of screw complications and adjacent segment disease were found after using Dynesys. The pedicle screw in the Dynesys system is not so easy to implant into the standard position and causes the screw to protrude more prominently from the pedicle. Little is known about how the biomechanical effects are influenced by the Dynesys screw profile. Methods: The Dynesys was implanted in a 3-dimensional, nonlinear, finite element model of the L1 to L5 lumbar spine. Different depths of screw position were modified in this model by 5 and 10mm out of the pedicle. The model was loaded to 150 N preload and controlled the same ROMs by 20, 15, 8, and 20 degrees in flexion, extension, torsion, and lateral bending, respectively. Resultant ROM, annulus stress, and facet contact force were analyzed at the surgical and adjacent level. Results: Under flexion, extension, and lateral bending, the Dynesys provided sufficient stability at the surgical level, but increased the ROM at the adjacent level. Under flexion and lateral bending, the Dynesys alleviated annulus stress at the surgical level, but increased annulus stress at the adjacent level. Under extension, the Dynesys decreased facet loading at the surgical level but increased facet loading at the adjacent level. Conclusions: This study found that the Dynesys system was able to restore spinal stability and alleviate loading on disc and facet at the surgical level, but greater ROM, annulus stress, and facet loading were found at the adjacent level. In addition, profile of the screw placement caused only a minor influence on the ROM, annulus stress, and facet loading, but the screw stress was noticeably increased. 關聯 Journal of spinal disorders & techniques, 23(6), 410-417 資料類型 article dc.contributor 神科所 en_US dc.creator (作者) 施世亮 zh_TW dc.creator (作者) Liu, Chien-Lin ; Zhong, Zheng-Cheng ; Shih, Shih-Liang ; Huang, Chinghua ; Lee, Yong-Eng ; Chen, Chen-Sheng en_US dc.date (日期) 2010-08 en_US dc.date.accessioned 19-Nov-2014 10:41:46 (UTC+8) - dc.date.available 19-Nov-2014 10:41:46 (UTC+8) - dc.date.issued (上傳時間) 19-Nov-2014 10:41:46 (UTC+8) - dc.identifier.uri (URI) http://nccur.lib.nccu.edu.tw/handle/140.119/71538 - dc.description.abstract (摘要) Study Design: Displacement-controlled finite element analysis was used to evaluate the mechanical behavior of the lumbar spine after insertion of the Dynesys dynamic stabilization system. Objective: This study aimed to investigate whether different depths of screw placement of Dynesys would affect load sharing of screw, range of motion (ROM), annulus stress, and facet contact force. Summary of Background Data: In clinical follow-up, a high rate of screw complications and adjacent segment disease were found after using Dynesys. The pedicle screw in the Dynesys system is not so easy to implant into the standard position and causes the screw to protrude more prominently from the pedicle. Little is known about how the biomechanical effects are influenced by the Dynesys screw profile. Methods: The Dynesys was implanted in a 3-dimensional, nonlinear, finite element model of the L1 to L5 lumbar spine. Different depths of screw position were modified in this model by 5 and 10mm out of the pedicle. The model was loaded to 150 N preload and controlled the same ROMs by 20, 15, 8, and 20 degrees in flexion, extension, torsion, and lateral bending, respectively. Resultant ROM, annulus stress, and facet contact force were analyzed at the surgical and adjacent level. Results: Under flexion, extension, and lateral bending, the Dynesys provided sufficient stability at the surgical level, but increased the ROM at the adjacent level. Under flexion and lateral bending, the Dynesys alleviated annulus stress at the surgical level, but increased annulus stress at the adjacent level. Under extension, the Dynesys decreased facet loading at the surgical level but increased facet loading at the adjacent level. Conclusions: This study found that the Dynesys system was able to restore spinal stability and alleviate loading on disc and facet at the surgical level, but greater ROM, annulus stress, and facet loading were found at the adjacent level. In addition, profile of the screw placement caused only a minor influence on the ROM, annulus stress, and facet loading, but the screw stress was noticeably increased. en_US dc.format.extent 176 bytes - dc.format.mimetype text/html - dc.language.iso en_US - dc.relation (關聯) Journal of spinal disorders & techniques, 23(6), 410-417 en_US dc.title (題名) Influence of Dynesys system screw profile on adjacent segment and screw en_US dc.type (資料類型) article en
