O-arm导航辅助下儿童颈椎椎弓根螺钉置钉的精确性及安全性评估

Accuracy and safety assessment of O-arm assisted cervical pedicle screw placement in children

中文关键词:  儿童  颈椎椎弓根螺钉  精确性  O-arm导航

英文关键词:Pediatric  Cervical pedicle screw  Accuracy  O-arm navigation

中文摘要:

  【摘要】 目的：评估O-arm导航辅助下儿童颈椎椎弓根螺钉置入的精确性及安全性。方法：回顾性分析2015年1月~2021年12月接受O-arm导航辅助下颈椎椎弓根螺钉置入的27例儿童患者，其中寰枢椎脱位7例，先天性颈胸椎脊柱畸形12例，神经纤维瘤病伴颈胸段萎缩性脊柱侧凸4例，Gorham′s病2例，颈椎肿瘤2例，年龄4~15岁（8.2±3.2岁），所有患者均接受O-arm导航辅助下颈椎后路椎弓根螺钉内固定术治疗。术前在颈椎CT椎弓根的最宽横断面上对每个节段的椎弓根宽度进行测量并将宽度<3.5mm的椎弓根定义为高风险椎弓根，术中O-arm导航辅助下置入颈椎椎弓根螺钉，术后即刻行CT扫描评估CPS置入的精确性：0级，螺钉无破壁；1级，螺钉破壁<25%螺钉直径；2级，螺钉破壁25%~50%螺钉直径且侵犯内侧壁或下壁；3级，螺钉破壁25%~50%螺钉直径且侵犯外侧壁或上壁；4级，螺钉破壁>50%螺钉直径。收集分析不同节段CPS破壁的数量及等级并记录并发症的发生情况。结果：所有患儿共置入109枚CPS，术前测得平均椎弓根直径3.49±0.58mm（C3-6），其中高风险螺钉36枚。置入的颈椎节段分布为C1 13枚（11.9%），C2 25枚（22.9%），C3 8枚（7.3%），C4 17枚（15.6%），C5 14枚（12.8%），C6 17枚（15.6%），C7 15枚（13.8%）。术后CT示100枚（91.7%）CPS位置良好（≤2级），5枚（4.6%）有3级破壁，4枚（3.7%）有4级破壁，未发现椎动脉或脊髓神经根损害等手术并发症。C4椎体受体位及导航偏移影响相对发生破壁可能性较大。4级破壁均因术前椎弓根极细（平均2.78mm），无明显神经并发症，故未二次手术调整或拆除。结论：O-arm导航辅助下行儿童颈椎椎弓根螺钉置钉在不同的儿童颈椎疾病中具有较高的置钉精确性，具有较高的安全性。

英文摘要:

  【Abstract】 Objectives: To evaluate the accuracy and safety of cervical pedicle screw implantation in children with O-arm navigation assistance. Methods: This study retrospectively analyzed 27 pediatric patients with cervical spine disease who underwent cervical pedicle screw implantation with O-arm navigation assistance between January 2015 and December 2021. The patients aged 4-15(8.2±3.2) years, among which, there were 7 cases of atlantoaxial dislocation, 12 cases of congenital cervical-thoracic deformity, 4 cases of neurofibromatosis with cervicothoracic atrophic scoliosis, 2 cases of Gorham′s disease, and 2 cases of neoplasms. All the patients were treated with O-arm navigation-assisted posterior cervical pedicle screw internal fixation. Preoperatively, the pedicle width of each segment was measured on the widest cross-sectional image of cervical CT scans, and pedicles <3.5mm in width were defined as high-risk pedicles, and during operation, cervical pedicle screws(CPS) were inserted under O-arm navigation guidance. The accuracy of CPS implantation was evaluated immediate postoperatively by CT scans(grade 0: no breach; grade 1: breach <25% screw diameter; grade 2: breach by 25%-50% the screw diameter and invading the internal or lower wall; grade 3: breach by 25%-50% the screw diameter and invading the external or upper wall; grade 4: breach>50% screw diameter). The CPS breach numbers and grades of different levels, as well as complications were recorded. Results: A total of 109 CPSs were implanted, the mean preoperative pedicle diameter was 3.49±0.58mm(C3-6), including 36 high-risk screws. And the screw distributions by segments were C1 13(11.9%), C2 25(22.9%), C3 8(7.3%), C4 17(15.6%), C5 14(12.8%), C6 17(15.6%), and C7 15(13.8%). Postoperative CT scan showed that 100(91.7%) CPSs were well positioned(≤grade 2), 5(4.6%) CPSs were of grade 3, and 4(3.7%) CPSs were of grade 4. No surgical complications such as vertebral artery or nerve root injury were found. The C4 vertebra was relatively more likely to undergo wall breakage due to positional influence and navigational excursions. Breach of grade 4 was due to extremely thin preoperative pedicles(mean 2.78mm), which did not require immediate secondary surgical adjustment or removal in the absence of significant neurologic complications. Conclusions: O-arm navigation-assisted CPS placement has a high accuracy in different cervical diseases in children, and therefore is endowed with high safety.