【摘要】 目的:评价导航系统辅助下颈椎(C3￣C7)椎弓根螺钉内固定置钉的准确性。方法:将32具成人尸体颈椎标本随机分为4组,分别采用盲法、透视法、透视导航法和CT导航法进行下颈椎椎弓根螺钉置入。术后采用标本大体解剖观察的方法评价置钉准确性。分优(螺钉完全在椎弓根内)、可(仅有螺纹穿出,对周围组织无损伤)和差(螺钉明显穿出)进行统计。结果:共置入螺钉318枚。盲法80枚,平均手术时间27min,优29枚(36.3%)、可21枚(26.3%)、差30枚(37.5%);透视法78枚(有1例C4、C5右侧椎弓根均细小,不能容纳3.5mm螺钉),平均手术时间112min,优35枚(44.9%)、可29枚(37.2%)、差14枚(17.9%);透视导航法80枚,平均手术时间69min,优34枚(42.5%),可36枚(45%),差10枚(12.5%);CT导航法80枚,平均手术时间98min,优70枚(87.5%)、可10枚(12.5%)。各组间手术时间均有显著性差异(P<0.05),透视法与透视导航法的置钉准确率间无显著性差异,其余各组间均有显著性差异(P<0.05)。结论:单纯根据术前影像结果盲法行下颈椎椎弓根螺钉内固定不安全。透视法和透视导航法可提高置钉准确性,但手术风险仍较大,透视导航法比透视法置钉的手术时间缩短。CT导航法并未比透视法增加手术时间,但置钉准确性显著提高。更多还原

【Abstract】 Objective:To assess the accuracy of transpedicular screw placement in the lower cervical spines(C3-C7) assisted by navigation system.Method:32 human cadaveric cervical spines were utilized and 3.5mm screws were placed into the C3~C7 pedicles following four kinds of techniques:blind screw placement(group 1),assisted by X-ray fluoroscopy(group 2),assisted by virtual fluoroscopy navigation system(group 3),assisted by CT-based navigation system(group 4).Thereafter,cortical integrity of every sample was examined by anatomic dissection.Cortical breaches were classified by critical or non-critical breaches.Result:All together,there were 318 pedicles involved.Group 1,80 pedicles,the average operation time per sample was 27 minutes.36.3% of the screws were placed entirely within the pedicle,26.3% showed non-critical breaches, and 37.5% showed critical breaches.Group 2,78 pedicles,the average operation time was 112 minutes.44.9% were placed entirely within the pedicle,37.2% showed non-critical breaches,and 17.9% showed critical breaches.Group 3,80 pedicles,the average operation time was 69 minutes.42.5% were placed entirely within the pedicle,45% showed non-critical breaches,and 12.5% showed critical breaches.Group 4,80 pedicles,the average operation time was 98 minutes.87.5% were placed entirely within the pedicle,12.5% showed non-critical breaches.There were statistically significant difference among the four groups with respect to the average operation time and the accuracy of screw placement(P<0.05),except for the comparison of accuracy between fluoroscopy and virtual fluoroscopy navigation system,which had no statistically significant difference.Conclusion:Blind screw placement is insecure.The assistance of fluoroscopy or virtual fluoroscopy navigation system definitely enhances accuracy.But the odds of severe breaches are still high.The virtual fluoroscopy navigation system has a shorter operation time than fluoroscopy,however it can not improve the accuracy of screw placement.CT-based navigation system drastically enhances accuracy and further improves the security of transpedicular screw placement.更多还原