3D打印椎弓根导航模板在下颈椎椎弓根置钉中的临床应用

Clinical application of 3D-printed drill guiding template in pedicle screw insertion in subaxial cervical spine

中文关键词:  下颈椎  椎弓根螺钉  导航模板  3D打印

英文关键词:Subaxial cervical spine  Pedicle screw  Drill guiding template  3D printed

中文摘要:

  【摘要】 目的：探讨采用优化设计的3D打印椎弓根导航模板辅助下颈椎椎弓根螺钉置入的安全性和准确性。方法：回顾性分析2016年8月~2022年10月在我科行颈椎后路椎弓根螺钉内固定手术的患者42例，年龄32~74岁（50.1±9.8岁），随访13~25个月（19.6±3.2个月）。根据置钉方式分为导板组（n=22）和徒手组（n=20）：导板组采用优化的椎弓根钻孔导航模板设计方案，3D打印制作下颈椎椎弓根导航模板辅助椎弓根置钉，其中男性12例，女性10例，颈椎损伤或颈脊髓损伤6例，后纵韧带骨化症（OPLL）9例，颈椎管肿瘤5例，脊髓型颈椎病2例；徒手组根据术前颈椎CT测量椎弓根角度、直径等参数，采用徒手置钉，其中男、女各10例，颈椎损伤或颈脊髓损伤4例，OPLL 10例，颈椎管肿瘤5例，脊髓型颈椎病1例。两组患者性别构成、年龄、诊断、术前VAS评分、JOA评分比较无统计学差异（P>0.05）。记录两组患者手术时间、术中出血量；术后1周颈椎CT扫描，按照Kaneyama方法评估椎弓根置钉的准确性：0级，螺钉完全位于椎弓根内；1级，穿破椎弓根的部分<螺钉直径的50%；2级，穿破椎弓根的部分>螺钉直径的50%；3级，椎弓根螺钉完全位于椎弓根外。0级或1级定义为椎弓根置钉准确，2级或3级为螺钉误置。记录患者的围手术期并发症，统计并比较两组术后12个月疼痛视觉模拟评分（VAS）、日本骨科学会（JOA）评分。结果：42例患者手术顺利，导板组手术时间102.2±16.1min，术中出血量89.3±17.7mL；均少于徒手组142.8±20.9min，133.3±34.0mL（P<0.01）。42例患者共置入下颈椎椎弓根螺钉216枚：导板组118枚，其中0级90枚，1级22枚，2级5枚，3级1枚，置钉准确率94.9%（112/118）；徒手组98枚，其中0级48枚，1级36枚，2级10枚，3级4枚，置钉准确率85.7%（84/98）。导板组置钉准确率显著性高于徒手组（P<0.05）。两组患者均未出现螺钉相关神经血管损伤，无内固定松动断裂并发症，术后12个月VAS评分较术前显著性降低（P<0.01），JOA评分较术前显著性提高（P<0.01），两组间比较无显著性差异（P>0.05）。结论：3D打印椎弓根导航模板的优化设计方案有助于提高下颈椎椎弓根置钉的准确性。

英文摘要:

  【Abstract】 Objectives: To explore the safety and accuracy of subaxial cervical pedicle screw(CPS) insertion assisted with optimized 3D-printed drill guiding template(DGT). Methods: A retrospective study was conducted to analyze the clinical data of 42 patients aged 32-74 years (50.1±9.8 years) who underwent posterior cervical pedicle screw internal fixation between August 2016 and October 2022. The patients were followed up for 13-25 months(19.6±3.2 months). They were divided into two groups of guiding template group(n=22) and free-hand group(n=20) according to the method of pedicle screw insertion. In the guiding template group, the subaxial CPSs insertions were assisted with 3D-printed DGT, designed individually for each patient based on the design scheme of an optimized pedicle drill guiding template, and the patients consisted of 12 males and 10 females, among which 6 patients were with cervical spine injury or spinal cord injury, 9 were with ossification of posterior longitudinal ligament(OPLL), 5 were with intraspinal tumor, and 2 were with cervical spondylotic myelopathy. In the free-hand group, the subaxial CPSs were inserted with free hand according to the cervical parameters such as pedicle angle and diameter on the CT images measured before operation, and the patients consisted of 10 males and 10 females, among which 4 patients were with cervical spine injury or spinal cord injury, 10 with OPLL, 5 with intraspinal tumor, and 1 with cervical spondylotic myelopathy. There were no significant differences in sex, age, disease, and preoperative visual analogue scale(VAS) score and Japanese Orthopaedic Association(JOA) score between the two groups(P>0.05). The operative time, intraoperative blood loss, and postoperative 12 months of VAS and JOA scores were recorded and compared．CT scan was performed at 1 week after operation on cervical spine, and the accuracy of pedicle screw placement was evaluated in accordance with Kaneyama′s evaluation method: Grade 0, screw was contained in the pedicle; Grade 1, screw penetrated pedicle<50% of the screw diameter; Grade 2, screw penetrated pedicle>50% of the screw diameter; Grade 3, screw completely penetrated the pedicle. Grades 0 and 1 were considered accurate placement, and grades 2 and 3 were considered misplacement. The perioperative complications were recorded for each patient in the two groups. Results: The operative time, intra-operative blood loss in guiding template group(102.2±16.1min, 89.3±17.7mL) were statistically less than those in free-hand group(142.8±20.9min, 133.3±34.0mL)(P<0.01). A total of 216 CPSs were placed: 118 in the guiding template group, including 90 screws of grade 0, 22 screws of grade 1, 5 screws of grade 2, 1 screw of grade 3, with an accuracy rate of 94.9%(112/118); And 98 in the free-hand group, including 48 screws of grade 0, 36 screws of grade 1, 10 screws of grade 2, and 4 screws of grade 3, with an accuracy rate of 85.7%(84/98). The accuracy rate of pedicle screw insertion was significant higher in the guiding template group than that in the free-hand group(P<0.05). No major neurovascular complications nor internal fixation loosening or breakages were observed in two groups of patients. At 12 months after operation, the VAS score in both groups was statistically less than that before operation(P<0.01), and the JOA score in both groups was statistically more than that before operation(P<0.01), and there were no significant differences in VAS score and JOA score between groups, respectively(P>0.05). Conclusions: The optimized design scheme of 3D-printed DGT is helpful in improving the accuracy and safety of subaxial CPS insertion.