Sengupta D K, Bucklen Brandon, McAfee Paul C, Nichols Jeff, Angara Raghavendra, Khalil Saif
Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756, USA.
Adv Orthop. 2013;2013:745610. doi: 10.1155/2013/745610. Epub 2013 Aug 4.
Alternatives to conventional rigid fusion have been proposed for several conditions related to degenerative disc disease when nonoperative treatment has failed. Semirigid fixation, in the form of dynamic stabilization or PEEK rods, is expected to provide compression under loading as well as an intermediate level of stabilization. This study systematically examines both the load-sharing characteristics and kinematics of these two devices compared to the standard of internal rigid fixators. Load-sharing was studied by using digital pressure films inserted between an artificially machined disc and two loading fixtures. Rigid rods, PEEK rods, and the dynamic stabilization system were inserted posteriorly for stabilization. The kinematics were quantified on ten, human, cadaver lumbosacral spines (L3-S1) which were tested under a pure bending moment, in flexion-extension, lateral bending, and axial rotation. The magnitude of load transmission through the anterior column was significantly greater with the dynamic device compared to PEEK rods and rigid rods. The contact pressures were distributed more uniformly, throughout the disc with the dynamic stabilization devices, and had smaller maximum point-loading (pressures) on any particular point within the disc. Kinematically, the motion was reduced by both semirigid devices similarly in all directions, with slight rigidity imparted by a lateral interbody device.
当非手术治疗失败时，针对与退行性椎间盘疾病相关的几种情况，人们提出了传统刚性融合的替代方法。半刚性固定，如动态稳定或聚醚醚酮（PEEK）棒，有望在加载时提供压缩力以及中等程度的稳定性。本研究系统地研究了与标准内部刚性固定器相比，这两种装置的负载分担特性和运动学。通过在人工加工的椎间盘和两个加载夹具之间插入数字压力膜来研究负载分担。刚性棒、PEEK棒和动态稳定系统从后方插入以实现稳定。在十个完整的人体腰骶椎（L3-S1）上对运动学进行了量化，这些标本在纯弯矩、屈伸、侧弯和轴向旋转下进行测试。与PEEK棒和刚性棒相比，动态装置通过前柱传递的负载大小明显更大。动态稳定装置使椎间盘内的接触压力分布更均匀，并且在椎间盘内任何特定点的最大点加载（压力）更小。在运动学方面，两种半刚性装置在所有方向上类似地减少了运动，椎间外侧装置施加了轻微的刚性。
