Cagli S, Crawford N R, Sonntag V K, Dickman C A
Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013-4496, USA.
J Neurosurg. 2001 Jan;94(1 Suppl):51-60. doi: 10.3171/spi.2001.94.1.0051.
The authors sought to determine the biomechanical effectiveness of threaded interbody cages or dowels compared with that achieved using pedicle screw instrumentation in resisting Grade I lumbar spine degenerative spondylolisthesis.
Thirty-three levels obtained from seven cadaveric lumbar spines were instrumented with cages or dowels, pedicle screw/rod instrumentation, or both. Entire specimens were loaded with nonconstraining torques. Each level was loaded with anteroposterior shear forces while an optical system was used to measure the specimen's motion at individual levels. Pedicle screw/rods outperformed interbody cages and dowels in treating spondylolisthesis. Cages or dowels alone provided only moderate biomechanical stability, and their effectiveness depended heavily on the integrity of the ligaments and remaining annulus, whereas the success of pedicle screw fixation relied predominantly on the integrity of the bone for solid fixation. Little biomechanical difference was demonstrated between cages and dowels; both devices were susceptible to loosening with cyclic fatigue.
Biomechanically, cages or dowels alone were suboptimal for treating lumbar spondylolisthesis, especially compared with pedicle screw/rods. Threaded cages or dowels used together with pedicle screws/rods created the most stable construct.
作者试图确定与使用椎弓根螺钉器械相比，螺纹椎间融合器或销钉在抵抗I度腰椎退行性滑脱方面的生物力学有效性。
从7具尸体腰椎获取的33个节段分别用融合器或销钉、椎弓根螺钉/棒器械或两者同时进行固定。对整个标本施加非约束性扭矩。每个节段施加前后剪切力，同时使用光学系统测量标本在各个节段的运动。在治疗腰椎滑脱方面，椎弓根螺钉/棒优于椎间融合器和销钉。单独使用融合器或销钉仅提供中等程度的生物力学稳定性，其有效性在很大程度上取决于韧带和剩余纤维环的完整性，而椎弓根螺钉固定的成功主要依赖于骨的完整性以实现牢固固定。融合器和销钉之间未显示出明显的生物力学差异；两种器械都容易因循环疲劳而松动。
从生物力学角度来看，单独使用融合器或销钉治疗腰椎滑脱效果欠佳，尤其是与椎弓根螺钉/棒相比。螺纹融合器或销钉与椎弓根螺钉/棒联合使用可构建最稳定的结构。
