O型臂联合CT三维导航系统辅助颈椎椎弓根螺钉置入的准确性研究

Accuracy study of cervical pedicle screw placement assisted by O-arm combined with CT 3D navigation system

中文关键词:  O型臂导航系统  椎弓根螺钉  侧块螺钉  置钉准确性

英文关键词:O-arm navigation  Pedicle screw  Lateral mass screw  Accuracy of screw placement

中文摘要:

  【摘要】 目的：探讨O型臂联合CT三维导航系统辅助颈椎椎弓根螺钉置钉的准确性，并与侧块螺钉置钉进行比较。方法：回顾性分析2017年3月~2021年2月在我院分别使用O型臂联合CT三维导航系统辅助置入椎弓根螺钉与徒手置入侧块螺钉行颈椎后路内固定术的54例患者，其中男44例，女10例，年龄42~79岁（58.3±9.3岁）。根据置钉种类不同分组：A组通过O型臂联合CT三维导航系统置入C3~C7椎弓根螺钉，B组C3~C6徒手置入侧块螺钉，C7徒手置入椎弓根螺钉。两组间性别、年龄无统计学差异（P>0.05）。记录并比较两组术中出血量、手术时间及围手术期并发症（颈后路血肿、严重伤口感染、血管神经损伤、螺钉拔出等）情况，在拔除引流管后行颈椎CT平扫，根据椎弓根螺钉穿破椎弓根皮质的程度，将置钉准确性分为4级：螺钉完全位于椎弓根内无骨皮质的穿破为0级；螺钉穿破皮质<2mm，或小于螺钉直径的50%为1级；螺钉穿破皮质≥2mm且<4mm或大于直径的50%为2级；螺钉穿破皮质≥4mm或螺钉完全穿破皮质进入椎管内或椎动脉孔内为3级。根据侧块螺钉穿破椎体侧块的程度，参照上述分级标准记录侧块螺钉置钉精确性。将0、1级评价为螺钉位置满意，2、3级评价为螺钉误置，计算误置率（误置螺钉数/置钉总数×100％）。统计两组螺钉置入情况，比较两组C7椎弓根螺钉置钉准确性。结果：两组的手术时间（251±59min和235±56min）及术中出血量（521±200ml和448±213ml）差异无统计学意义（P＞0.05）。A组共置入椎弓根螺钉247枚，其中螺钉位置满意239枚，螺钉误置8枚，误置率3.2%。B组共置入螺钉209枚，其中椎弓根螺钉52枚，螺钉位置满意50枚，螺钉误置2枚，误置率3.8%；置入侧块螺钉（C3~C6）157枚，螺钉位置满意144枚，螺钉误置3枚，误置率1.9%；A、B两组C7椎弓根螺钉置钉准确性无统计学差异（P>0.05）。两组均无与置钉相关的血管、神经并发症，均未出现严重伤口感染、医源性神经血管损伤、颈后路血肿、螺钉拔出等围手术期并发症。结论：O型臂联合CT三维导航系统安全有效置入颈椎椎弓根螺钉，置钉准确性高，与传统侧块螺钉固定相比，并未显著延长手术时间、增加术中出血量或围手术期螺钉相关并发症。

英文摘要:

  【Abstract】 Objectives: To investigate the accuracy of cervical pedicle screw placement assisted by O-arm combined with CT 3D navigation system, and to compare with lateral mass screw fixation. Methods: 54 patients who underwent posterior cervical fixation in our hospital from March 2017 to February 2021 were included in this study, which included 44 males and 10 females, aged 42-79 years(58.3±9.3 years). They were divided into two groups: O-arm navigation assisted C3-C7 pedicle screw placement group(group A) and freehand C3-C6 lateral mass screw placement and C7 pedicle screw placement group(group B). There were no significant differences in gender and age between the two groups(P>0.05). The amount of intraoperative blood loss, operative time and perioperative complications (posterior cervical hematoma, severe infection, vascular and nerve injury, etc.) were compared between the two groups. Plain CT scan was performed after removal of drainage tube, and according to the penetration degree of pedicle cortex by screw, the screw placement accuracy was classified into four grades: Grade 0, the screw was placed in the pedicle without penetration; Grade 1, penetration<2mm or less than 50% of the screw diameter; Grade 2, 2mm≤penetration<4mm or penetration>50% of the screw diameter; Grade 3, penetration≥4mm or screw penetrated cortex and entered into spinal canal or vertebral artery foramen. Also, the placement accuracy of lateral mass screw was recorded with reference to the above grading standard on the basis of penetration degree of lateral mass by screw. Grades 0 and 1 were evaluated as satisfactory placement, and grades 2 and 3 were evaluated as screw misplacement, and the misplacement rate(number of misplacement screws/total number of screws×100%) was calculated. The screw placement of both groups was analyzed, and the accuracy of C7 pedicle screw placement was compared between the two groups. Results: There were no significant differences in operative time (251±59min and 235±56min) and intraoperative blood loss(521±200ml and 448±213ml) between group A and group B(P>0.05). In group A, a total of 247 pedicle screws were placed, including 239 screws of grades 0 and 1 and 8 screws of grades 2 and 3, with a total misplacement rate of 3.2%. In group B, a total of 209 screws were inserted, including 157 C3-C6 lateral mass screws, and of which 144 screws were of grades 0 and 1 and 3 screws of grades 2 and 3, with a total misplacement rate of 1.9%; and 52 cervical pedicle screws, of which 50 screws were of grades 0 and 1 and 2 screws of grades 2 and 3, with a total misplacement rate of 3.8%. The placement accuracy of C7 pedicle screw between the two groups showed no statistical significance(P>0.05). There were no vascular of neurological complications related to screw placement, no serious wound infection, iatrogenic neurovascular injury, posterior cervical hematoma, screw removal and other perioperative complications in both groups. Conclusions: It is safe and effective to use O-arm combined with CT 3D navigation system in assisting cervical pedicle screw placement, with a placement accuracy of 96.8%. Comparing with conventional lateral mass screw, none of the operative time, intraoperative blood loss, or perioperative screw related complications is significantly increased.