Wu S S, Liang P L, Pai W M, Au M K, Lin L C
Department of Orthopaedic Surgery, Tri-Service General Hospital, National Defense Medical Center, Taiwan, Republic of China.
Proc Natl Sci Counc Repub China B. 1990 Dec;14(4):209-16.
Spinal transpedicular fixation has gained widespread popularity in the past 5 years. In biomechanical studies, the deeply-inserted transpedicular screws withstood the largest number of cycles in the cephalad-caudad and medial-lateral direction before failure. However, in clinical practice, the risk of screw placement which is too far medially or too far laterally do exist. The optimization of increasing screw depth to avoid complication is of significant clinical importance. A Spinal Pedicle Finder (S.P.F) has been designed for transpedicular screws and a prototype has been completed. It is composed of an I-shaped body with a pair of front rails and a pair of rear rails. The front rail comprises two positioning arms that fit against the laminal bony crest, and the rear rail comprises two guiding bases that provide the transpedicular pin inserted with a specific angle. Both positioning arms and both guiding bases can be adjusted synchronously, and the specific angle over the guiding bases can be pre-set preoperatively according to the angle of pedicle axis. To date, in 7 cases (5 fracture and 2 spondylolisthesis) transpedicular screw fixation has been applied by aid of the S.P.F. Two-level fixation was applied in a fracture group and three-level fixation was applied in a spondylolisthesis group. The position of the transpedicular screw has been checked by CT scan postoperatively. A total of 32 transpedicular screws were inserted and all were in the pedicle and vertebral body except in one instances. One transpedicular screw was malpositioned on one side, partially lateral to the pedicle. However, this malposition did not cause any neurologic problem, such as dural tear, nerve root injury or other. Clinical experience has demonstrated its efficacy and safety.
在过去5年中，脊柱经椎弓根固定术已得到广泛应用。在生物力学研究中，深度植入的经椎弓根螺钉在头-尾侧和内-外侧方向承受的循环次数最多，直至失效。然而，在临床实践中，螺钉放置位置过内侧或过外侧的风险确实存在。增加螺钉深度以避免并发症的优化方法具有重要的临床意义。一种用于经椎弓根螺钉的脊柱椎弓根定位器（S.P.F）已设计完成并制作出了原型。它由一个I形主体、一对前导轨和一对后导轨组成。前导轨包括两个与椎板骨嵴贴合的定位臂，后导轨包括两个以特定角度为经椎弓根针提供导向的导向基座。两个定位臂和两个导向基座均可同步调节，导向基座上的特定角度可在术前根据椎弓根轴线角度预先设定。迄今为止，已借助S.P.F对7例患者（5例骨折和2例腰椎滑脱）实施了经椎弓根螺钉固定术。骨折组采用两级固定，腰椎滑脱组采用三级固定。术后通过CT扫描检查经椎弓根螺钉的位置。共植入32枚经椎弓根螺钉，除1例情况外，所有螺钉均位于椎弓根和椎体内。一侧的一枚经椎弓根螺钉位置不当，部分位于椎弓根外侧。然而，这种位置不当并未引起任何神经问题，如硬脊膜撕裂、神经根损伤或其他问题。临床经验已证明了其有效性和安全性。
