Bostelmann R, Benini A
Schulthess Klinik, Zürich.
Praxis (Bern 1994). 2004 Jan 21;93(4):96-102. doi: 10.1024/0369-8394.93.4.96.
A well-known problem occurring with lumbar fusion is the incorrect placement of the pedicular screws. Previous studies have shown a rate of incorrect insertion of the screws ranging from 10 to 40%. An incorrectly inserted screw with medial perforation through the pedicle may cause an acute injury of the root passing medially to the pedicle. In case of wrong laterally placed screw the root exiting along the lateral wall of pedicle can be damaged. As a rule, a neurological deficit due to such an injury is irreversible. Vascular lesions are much rarer. Screws malposition, no matter in which direction the insertion should be wrong, leads very often to failed fusion. To reduce the rate of incorrectly placed transpedicular screws, computed tomography based navigation has been introduced. It allows the surgeon multidimensional control of the screw position in virtual reality and real time during insertion. The experience with the first 109 patients in which transpedicular lumbar fusion was performed this way in the Neurosurgical Dpt of the Spine Unit in the Schulthess Clinic in Zurich is described. The computed assisted surgery (CAS) takes slightly more time than the conventional procedure. The significantly increased accuracy of pedicle screw insertion repays this disadvantage generously.
腰椎融合术中一个众所周知的问题是椎弓根螺钉放置错误。以往研究表明，螺钉置入错误的发生率在10%至40%之间。螺钉向内穿破椎弓根的错误置入可能会导致向内侧通过椎弓根的神经根急性损伤。如果螺钉向外侧错误放置，沿椎弓根侧壁穿出的神经根可能会受损。通常，这种损伤导致的神经功能缺损是不可逆的。血管损伤则更为罕见。无论螺钉向哪个方向置入错误，螺钉位置不当往往会导致融合失败。为了降低椎弓根螺钉放置错误的发生率，已引入基于计算机断层扫描的导航技术。它使外科医生在置入过程中能够在虚拟现实中对螺钉位置进行多维度控制并实时监测。本文描述了苏黎世舒尔特黑斯诊所脊柱科神经外科对首批109例采用这种方式进行椎弓根腰椎融合术患者的经验。计算机辅助手术（CAS）比传统手术花费的时间略长。但椎弓根螺钉置入准确性的显著提高足以弥补这一缺点。
