寰椎椎弓根螺钉导向器的研制及初步应用

Development and application of atlas pedicle screw guider

目的设计一种导向装置,提供寰椎椎弓根螺钉的个体化置钉,并避免损伤寰椎周围的重要结构从而降低手术风险。方法采集30名成年患者的寰椎CT平扫三维重建影像数据,导入SPSS 21.0软件进行统计学分析,取95%医学参考值区间。确定进钉点处后弓高度、后结节中点到进钉点处的横向距离、进针点穿过侧块中点到前弓骨皮质的纵向距离等,为导向器设计提供数据支持。设计过程及步骤:(1)以寰椎后结节处为锚定点设计导向器固定装置;(2)以锚定点为基础,装配纵向提拉杆及横向游标支架,分别起到抵抗置钉外力作用及参照术前影像初步锁定进钉点位置等;(3)在横向支架上安装可调导针套筒,确定后弓进钉点的位置及进钉方向;(4)配套2mm导针、螺母、改锥等。临床试验:将设计出的导向器在寰枢椎脱位或不稳患者中试用,并设非导向器组作对照,统计比较两组置钉成功率及手术时间,评估导向器的实用性。结果导向器组的置钉成功率为96.15%(25/26),优于非导向器组(84.61%,22/26),差异有统计学意义(P=0.025);导向器组手术时间为(123.38±5.59)min,短于非导向器组(137.62±4.15)min,差异有统计学意义(P<0.05)。结论成功设计了一种寰椎椎弓根螺钉个体化置钉导向装置,该导向装置能提高手术效率。

Objective To design a nailing guiding device to improve individual atlas pedicle screw implantation,avoiding the damage of adjacent tissues and reducing the risk of operation.Methods Three-dimensional data of CT scan of 30 adult atlas were collected and analyzed by SPSS 21.0software with 95%reference value range.The height of the posterior arch in starting point,the horizontal distance between starting point and the center of posterior tubercle,and the longitudinal distance from starting point to cortical bone of anterior arch through the center of lateral mass were determined for designing the guiding device.The designing steps included：（1）the fixing device of guider was designed with posterior tubercle of atlas as the anchor point;（2）based on the anchor point,vertical lifting rod and lateral vernier stents were installed to resist the external force of nailing and to preliminarily locate the starting point refering to the preoperative imaging data,repectively;（3）a needle sleeve was installed on the transverse stents,and the position of starting point and the direction of screw were determined;and（4）other parts included 2 mm diameter needle,screw nut,screw driver,etc.Clinical study：the designed guider was used in patients with atlanto-axial dislocation or instability,and patients receiving tranditional therapy were taken controls.The efficay of designed guider was evaluated by comparing the success rates and operation time of the two methods.Results The nailing success rate of the designed guider was significantly higher than that of the control group（96.15% [25/26]vs 84.61%[22/26],P=0.025）.The Operation time of the guider group was significantly shorter than that of control group（[123.38±5.59]vs[137.62±4.15]min,P0.05）.Conclusion We have successfully designed an individual guiding device for atlas pedicle screw implantation,which can help to improve the operation efficiency.