C臂X线透视下分步引导上中胸椎椎弓根螺钉安全植入实验研究

Stepwise implantation of pedicle of upper-middle thoracic vertehral arch screws under guidance of C-shaped X-ray fluoroscopy:an experimental study

目的探索一种能术中监测并引导上中胸椎椎弓根螺钉安全植入的简单、经济、确实可行的方法。方法第一步:取6具正常成人T1～T8脊椎骨架标本,分解出单个椎体,导针沿椎弓根轴线进入,分别于进针点及针前端位于椎弓根中部、椎体后缘及椎体前缘皮质下,C臂X线透视记录、分析椎弓根轴线导针在进针点及不同进针深度时在正侧位透视图像上导针前端的位置,并推断出相关位置对应关系变化规律。第二步:根据第一步所得椎弓根轴线导针位置变化规律进行上中胸椎椎弓根螺钉植入。取6具T1～T8脊柱标本,C臂X线机引导分步植入椎弓根螺钉96枚,然后作CT检查,判定椎弓根螺钉位置。根据CT检查结果,判定C臂X线透视分步引导椎弓根螺钉植入的安全性及准确性,分为优(椎弓根螺钉安全位于椎弓根内)、可(螺钉穿破椎弓根内或外侧骨皮质较少,突破在2mm以内)、差(螺钉穿破椎弓根内外骨皮质较多,突破在2mm以上)3个等级。结果优90枚(93.8%),可6枚(6.2%)。结论C臂X线透视下分步引导上中胸椎椎弓根螺钉植入是一种简单、经济、确实可行的方法,具有安全、准确和实用特点。

Objective To explore a simple, practical and safe way of implanting pedicle of upper-middle thoracic vertebral arch screws under X-ray guidance, Methods First, 6 normal adult thoracic spine samples（T1 - T8） were selected, horn which single spine units were separated. A surgical probe went in along the pedicle axis. The C-shaped arm X-ray recorded the four probe positions： at the entering point, the front end of the probe in the middle of the pedicle, at the pack of the spine, and under the cortex of the front of the spine. The position of the front end of the probe at the entering point, and the front end of the probe at different depth at central-side perspective position were analyzed. The related positions and their corresponding changes Were also analyzed. Second, based on the changes mentioned above, different steps were adopted under the guidance of the C-shaped arm X-ray, to safely implant upper-middle thoracic pedicle screws. First, 6 T1-T8 spine samples were used, and under the guidance of the C-shaped arm device, 96 pedicle screws were implanted. After the operation, the spine samples were scanned through CT, and the positions of the screws were determined. According to the result of the CT scanning, the safety and accuracy of the implantation were evaluated as excellent （the screw was safely inside the pedicle）; good （the screw penetrated a little of the inside or outside bone cortex, within 2mm.） and failure （the screw penetrated a lot, more than 2mm）. Results Ninety screws （93.8%） were evaluated as excellent, 6 （6.2%） were good and there was no failure. Conclusion The implantation of upper-middle thoracic pedicle screw under the guidance of the C-shaped arm X-ray fluoroscopy is a simple and feasible method characterized by its safety, accuracy and practicability.