寰枢椎椎弓根螺钉固定在儿童上颈椎疾患中的应用

The application of C1-C2 pedicle screw internal fixation on the upper cervical diseases of children

目的报道5例9岁以下儿童由于不同原因所致寰枢椎不稳行颈后路寰枢椎椎弓根螺钉固定的病例,介绍手术方法、术中及术后注意事项。方法患儿5例,男1例,女4例,年龄2岁～9岁8个月,平均77.6个月。其中枢椎齿突肿瘤破坏致寰枢椎不稳1例,寰枢椎外伤性不稳定1例,寰枢椎发育性不稳定3例。所有患儿均有颈痛、颈椎活动受限及不同程度的脊髓受压症状。术前常规行颈椎X线照片(包括动力位)、颈椎MRI及颈椎三维CT扫描,并利用三维CT数据,采用计算机辅助设计-快速成型(computer aided design-rapidprototyping,CAD-RP)技术制作寰枢椎模型及椎弓根螺钉导向模板,在C型臂X线机监视下行寰枢椎椎弓根螺钉置入及固定融合。其中1例齿突肿瘤破坏致寰枢关节不稳的病儿,后路手术完成后行经口前路齿突肿瘤切除术。结果 5例手术均顺利完成,术中平均出血100～300mL,无手术并发症,术后患儿恢复良好,CT扫描螺钉位置正确。经3～6个月随访,患儿暂无不良反应。结论儿童寰枢椎不稳可以应用3.5mm直径的螺钉行椎弓根固定,C型臂X线机、三维CAD模型以及螺钉置入导板的运用可以提高螺钉置入的准确率。

Objective To report five cases of puerile （ 9 year） atlantoaxial instability which underwent C1-C2 pedicle screw internal fixation by posterior approach, and to introduce the surgical technique and the key point of intra- and post-operative management. Methods The average age of the five cases （1 male and 4 female） was 77.6 months （2 year to 9 year 8 month old）. All cases had atlantoaxial instability, one with dens tumor, one with atlantoaxial trauma, and three with dysplasia. All of the cases had syndromes of neck pain, limitation of cervical motion, and tetraparesis in different degrees due to the compression of spinal cord. Cervical X-ray including dynamic position, MRI, and three-dimension CT scanning were performed preoperatively. The computer aided design-rapid prototyping （CAD-RP） technique was utilized with the data from the three-dimension CT to create the atlantoaxial and pedicle screw drill models. The screw placement procedure was monitored by fluoroscopy. The case with dens tumor underwent posterior instrumentation followed by transoral tumor resection. Results All of the operations were successful with no complications. The average estimate blood loss was 100-300 mL. The CT scanning showed the screws were in good position. Follow-up at 3-6 months demonstrated all of the patients significant recovery and no complication happened. Conclusions The technique of pedicle screw internal fixation with 3.5 mm screw could be applied on the atlantoaxial instability of children. With the help of C-arm, 3D CAD and drill guide models, the anchor of the screws would be more accurate.