超声骨动力椎弓根寻路器的研制及其引导置钉的可行性研究

Development and feasibility study of pedicle screw implantation guided by ultrasonic pedicle pathfinder

中文关键词:  椎弓根寻路器  超声骨动力系统  椎弓根螺钉  辅助置钉

英文关键词:Pedicle pathfinder  Ultrasonic osteotome system  Pedicle screw  Assisted placement of pedicle screw

中文摘要:

  【摘要】 目的：探讨自行研制的超声骨动力椎弓根寻路器辅助椎弓根螺钉置入的准确度及安全性。方法：自行研制一种超声骨动力椎弓根寻路器，选择2具成年人脊柱标本（T1~L5节段），男性1具，年龄62岁，女性1具，年龄57岁，排除畸形、外伤及骨质疏松症等骨科疾病，将标本左侧椎弓根设置为实验组，通过超声骨动力椎弓根寻路器引导下置钉；右侧椎弓根设置为对照组，直视下徒手置钉。术中及术后即刻分别对两组标本行CT扫描，通过术中CT测量定位针长轴中线距椎弓根内外侧皮质距离；通过术后CT测量椎弓根螺钉穿出椎弓根皮质的距离并依据Neo法对置钉进行分级，统计两组精确置钉（0级置钉）、可接受置钉（Neo分级0级或1级）和不良置钉（Neo分级2级或3级）的情况。通过比较两组精确置钉率与不良置钉率上的整体差异，以及分别在上、中、下胸椎及腰椎的穿破皮质螺钉（Neo分级1、2、3级螺钉）的差异，评估两组间置钉精确性与安全性的差异。结果：两组各置入34枚定位针。实验组与对照组的定位针在上胸椎距皮质骨最小距离分别为2.77mm±1.05mm和0.59±2.31mm，中胸椎为1.97±1.01mm和0.98±1.70mm，下胸椎为3.02±0.93mm和2.53±0.83mm，腰椎为4.14±1.04mm和3.80±0.59mm。实验组有6枚定位针存在穿出的风险，对照组有14枚存在穿出的风险。在置钉方面，实验组与对照组的精确置钉率分别为82.36%和58.82%，可接受置钉率分别为97.06%和82.36%，不良置钉率分别为2.94%和17.64%。在所有穿破皮质螺钉中，实验组有1枚位于上胸椎（1级），2枚位于中胸椎（1级、2级各1枚），2枚位于下胸椎（1级2枚），1枚位于腰椎（1级）；而对照组有6枚位于上胸椎（1级2枚、2级2枚、3级2枚），5枚位于中胸椎（1级3枚、2级1枚、3级1枚），3枚位于下胸椎（1级）。实验组在胸腰椎精确置钉率、可接受置钉率上明显高于对照组，而在不良置钉率上明显低于对照组，且差异均具有统计学意义（P＜0.05）。实验组与对照组在上胸椎节段（T1~T4）穿破皮质螺钉比率存在统计学差异（P＜0.05），而在中下胸椎及腰椎无统计学差异（P＞0.05）。结论：与徒手置钉相比，超声骨动力椎弓根寻路器引导下置钉在胸腰椎节段具有较高的准确性与安全性。

英文摘要:

  【Abstract】 Objectives: To explore the accuracy and safety of using ultrasonic pedicle pathfinder to assist pedicle screw placement. Methods: 2 adult spine specimens (T1-L5) were selected as experimental subjects, including 1 male of 62 years old, and 1 female of 57 years old, excluding deformity, trauma and osteoporosis. The left pedicle of the specimen was setas the experimental group, inwhich the pedicle screw implantation was guided by ultrasonic pedicle pathfinder; and the right pedicle was set as the control group, in which the screw was implanted by freehand. CT scans were performed during and right to measure the distance between the long axis of the positioning pin and the cortex of the pedicle. After the operation, the distance between the pedicle screw and the pedicle cortex was measured and the placement levels of screws were graded by Neo′s method, and the quantitative and qualitative analysis of the results were performed. Then, the differences between accuracy placement rate(Neo′s level 0), acceptable placement rate(Neo′s level 0 or 1) and failure placement rate(Neo′s level 2 or 3) were compared between the two groups. Besides, the differences of both groups in the cortex penetration screws in the upper, middle, lower thoracic spine, and lumbar spine were analyzed to evaluate the differences in the accuracy and safety of screw placement between the two groups. Results: 34 positioning pins were placed in each group during the operation. The minimum distances of experimental group and control group between the positioning pins and the cortical bone of the pedicle were respectively: 2.77mm±1.05mm and 0.59±2.31mm in the upper thoracic spine, 1.97±1.01mm and 0.98±1.70mm in the middle thoracic spine, 3.02±0.93mm and 2.53±0.83mm in the lower thoracic spine, and 4.14±1.04mm and 3.80±0.59mm in the lumbar spine. 6 pins in the experimental group had risks to penetrate, while the number in the control group was 14. In the experimental group and control group,the accurate placement rates were 82.36% and 58.82% respectively, the acceptable placement rates were 97.06% and 82.36%, and the failure placement rates were 2.94% and 17.64%. Among all the screws penetrated cortex(namely screws of level 1, 2 or 3), the experimental group had 1 in the upper thoracic spine(level 1), 2 in the middle thoracic spine(1 of level 1 and 1 of level 2), 2 in the lower thoracic spine(level 2), and 1 in the lumbar spine(level 1); while the control group had 6 in the upper thoracic spine(2 of each level) and 5 in the middle thoracic spine(3 of level 1, 1 of level 2 and 1 of level 3), 3 in the lower thoracic spine(level 1), and 0 in the lumbar spine. In addition, the ratios of penetrated screws in the upper thoracic spine(T1-T4) between the experimental group and the control group was statistically different(P<0.05). But there was no significant difference in the middle and lower thoracic spine and lumbar spine(P>0.05). Conclusions: Compared with freehand, pedicle screw insertion guided by ultrasonic pedicle pathfinder can achieve higher accuracy and safety in the thoracolumbar level.