颈椎椎弓根螺钉“漏斗法”置钉技术的准确性评估

目的比较“漏斗法”和解剖标记法在颈椎弓根螺钉置人中的准确性和安全性。方法选取10具新鲜成人尸体标本截取颈椎节段（C3-C7），供体年龄51—75岁，平均62．5岁，每例标本术前采用双源CT薄层扫描（1mm／层）测量C3-C7的椎弓根形态，包括椎弓根的宽度、椎弓根的内偏角、矢状角度。所有标本随机分为两组，实验组采用“漏斗法”置钉技术，对照组采用传统置钉法（解剖标记法）植入椎弓根螺钉，术中不借助任何影像设备．术后检测螺钉植入结果，根据是否造成邻近组织损伤分为一般破损和严重破损．对两种方法的成功率和皮质破损率进行统计学比较。结果术前CT检查发现有5个椎弓根因太小不宜置钉．共计95个椎弓根植入螺钉纳入试验。漏斗法植入颈椎椎弓根钉50枚，其中41枚（82％）完全在椎弓根内，穿破椎弓根皮质9枚（18％），其中一般破损7枚（14％），关键破损2枚（4％），解剖标记法置入螺钉45枚，其中28枚（62．2％）完全在椎弓根内，穿破椎弓根皮质17枚（37．8％），其中一般破损11枚（24．4％），关键破损6枚（13．4％），两种方法的成功率和皮质破损率比较．差异有统计学意义。结论“漏斗法”植入技术植入颈椎椎弓根螺钉安全性和准确率均较高，优于解剖标记置钉法。

Comparative accuracy of cervical pedicle screws placement using funnel technique and topographic landmarks surgical technique

Objective To evaluate accuracy of cervical pedicle screws placement using funnel technique and topographic landmarks surgical technique. Methods Ten fresh frozen cervical spines（C3-C7）were used（100 pedicles, 20 pedicles per level）. The average specimen age was 62.5 years （range 51-75）;Pedicle width, Sagital angle and transverse angle were measured on preoperative axial computed tomography （1-mm slices）for every pedicle. All the specimens were randomly divided into two groups. The pcdicles （C3-C7）of experimental group were instrumented with 3.5-mm screws with the funnel technique and the control group with the Topographic landmarks surgical Technique. No intraoperative uoroscopy or radiographic control was used during any part of the entire procedure. Critical perforations （documented contact of a screw with,or an injury to,a spinal cord,nerve root,or vertebral artery）and noncritical perforations（a perforation with no critical contact）were recorded. Results In five pedicles（5%） the procedure was aborted because of a small or nonexistent pedicle medullary canal. In group I（funnel technique）, 82% of screws were placed in the pedicle correctly, 7 pedicles（18%） had noncritical breaches and 2 pedicles（4%） had critical perforations. In group II（topograph- ic landmarks surgical technique）, 62.2% of screws were placed in the pedicle correctly ,whereas 11 pedicles（24.4%） had noncritical perforations and 6 pedicles（13.3%） had critical perforations. Statistically significant differences were demonstrated between the two groups（P〈0.05）. Conclusion Funnel technique can enhance accuracy and further improve the safety of transpedicularscrew placement comparing with topographic landmarks surgical technique.