胸椎椎弓根螺钉和钩子对椎管内容积影响的比较  

Influence of different instrumentations (thoracic pedicle screws,thoracic laminar hooks and pedicle hooks) on volumes of spinal canal

作　　者：宋元进[1] 李明[2] 朱晓东[2] 许明[2] 孙海燕[1] 

机构地区：[1]89医院骨科十九病区,山东潍坊261021 [2]第二军医大学长海医院骨科,上海200433

出　　处：《实用医药杂志》2007年第10期1160-1163,共4页Practical Journal of Medicine & Pharmacy

摘　　要：目的探讨胸椎内固定(包括胸椎椎弓根螺钉和椎板钩、椎弓根钩)后对椎管内容积的影响。方法应用计算机辅助设计的软件(CAM)计算比较椎弓根螺钉和钩子侵占椎管容积,所有的椎弓根螺钉和钩子是由同一家制造商同一生产线生产的(Moss Miami DePuy Spine Johnson & Johnson company)。分析所有类型钩子,椎板钩的脚板(Footplate)是进入椎管内的部分,正确的椎管根钩是置入时应该骑跨在椎弓根上,因此椎弓根钩脚板的1/2计算为进入椎管的部分。结果直径4.75mm的螺钉平均侵占容积约为2.45mm3(内侧穿透0.5mm)到93.45mm3(内侧穿透3.0mm),直径5.5mm螺钉侵占容积约为1.50～93.1mm3。加上到螺钉阴影,平均占椎管内容积分别为10.88～130.25mm3和11.35～145.26mm3。钩子占椎管内容积,最窄刃的儿童椎弓根钩为54.75mm3,最宽刃的椎板钩为114.5mm3。结论直径4.75mm和5.5mm胸椎弓根螺钉内侧壁突破≥1.5mm与最小的儿童椎弓根钩子占用的椎管内容积相等,此外椎弓根内侧壁突破>3mm与最大的椎板钩子所占椎管内容积基本相同。考虑到螺钉影响因素,胸椎弓根螺钉突破内侧超过2mm与标准椎弓根钩子所占容积相等。Objective To investigate the influence on volumes of spinal canal when the instrumentations were placed（including thoracic pedicle screws,thoracic laminar hooks and pedicle hooks）. Methods Volumetric analysis of canal intrusion of pedicle screws and hooks was performed by computer aided designed CAM software. All implants were producted by a single manufacturer （Moss Miami DePuy Spine Johnson ＆ Johnson Company）. The volume of the footplate in line with the dorsal surface of the footplate was considered the intruding volume for laminar hooks, half of the volume of the footplate was considered to be the intruding volume for pedicle hooks since a properly positioned pedicle hook straddles the pedicle. Results Volumetric intrusion for a 4.75mm- screw ranged from 2.4 5mm^3 （0.5mm medial perforation） to 93.45mm^3 （3,0 mm perforation）. For a 5.5mm- screw, intrusion volume range was from 1.50mm^3 to 93.1mm^3. Accounting for the＂screw shadow,＂ the volumetric intrusion was 10.88mm^3 to 130.25mm^3 and l l.35mm^3 to 145,26mm^3, respectively. Hook volumetric intrusion ranged from 54.75mm^3 for a pediatric narrow-blade pedicle hook to 114.5mm^3 for a wide-blade laminar hook. Conclusion 4.75mm- or 5.5mm- thoracic pedicle have the same volumetric spinal canal intrusion as screw must have a medial perforation of 1.5 mm to a pediatric narrow-blade pedicle hook, the smallest hook footplate. Further, the medial violation must be 3mm to approach the same volumetric intrusion as the largest hook. Accounting for the ＂screw shadow,＂ a thoracic pedicle screw must have a medial perforation of 2 mm to approach the same intrusion volume as a standard pedicle hook.

关 键 词：椎管内容积 胸椎弓根螺钉 椎板钩 椎弓根钩 

分 类 号：R681.53[医药卫生—骨科学]