中文摘要：

目的：探讨寰枢椎椎弓根螺钉内固定手术治疗儿童寰枢椎脱位的可操作性和近期疗效。方法：2005年9月-2011年3月对16例儿童寰枢椎脱位患者采用寰枢椎椎弓根螺钉内固定术治疗，男9例．女7例；年龄5-13岁，平均9．1岁。均有枕颈部疼痛、颈部僵硬；3例有高位颈脊髓病表现，ASIA分级：D级2例，C级1例。术前均行颈椎正侧位及过伸过屈位X线片、CT和MRI检查，均诊断为寰枢椎脱位，其中寰椎横韧带断裂1例，寰枢椎骨折脱位1例，先天性齿状突畸形12例，寰枢椎固定旋转半脱位2例；颈脊髓受压5例。寰椎后弓（椎弓根）高度2．5-3．8mm，平均3．0mm；寰齿前间隙6-14mm，平均9mm。术前常规行牵引1-2周复位，完全复位7例，部分复位5例，不能复位4例。术中采用“寰椎椎弓根显露置钉法”，在直视下行C1、C2置钉，复位固定，植骨融合。随访患者症状和神经功能改善情况，定期行颈椎X线片及CT复查，了解内固定及植骨融合情况。结果：16例均行双侧寰枢椎椎弓根螺钉内固定，手术过程顺利，64枚螺钉均成功置入，复位固定满意，无术中、术后神经和血管并发症。术中出血150-650ml，平均300ml；手术时间100-190min，平均130min。12例随访12-72个月，平均28．5个月，术后3-6个月寰枢椎均骨性融合；末次随访时，颈枕症状明显改善，3例术前有脊髓功能损害者均好转，2例术前ASIA分级D级者恢复到E级，1例术前ASIA分级C级者恢复到D级：未发现螺钉松动、断钉和寰枢椎再移位现象，未发现曲轴现象。结论：采用“寰椎椎弓根显露置钉法”行寰椎椎弓根螺钉内固定可操作性强，置钉安全性高；寰枢椎椎弓根螺钉内固定治疗儿童寰枢椎脱位的近期疗效满意。

英文摘要：

Objectives： To investigate the surgical feasibility and short-term clinical outcome of C1-C2 pedi- cle screw fixation for pediatric atlantoaxial dislocation. Methods： Between September 2005 and March 2011, 16 cases suffering from pediatric atlantoaxial dislocation undergoing atlantoaxial pedicle screw instrumentation were reviewed retrospectively. There were 9 males and 7 females with the age at time of surgery ranging from 5 to 13 years （mean, 9.1 years）. All patients presented with pain at craniocervical junction and neck stiffness. 3 cases were complicated with medulla compression, and according to ASIA classification, there were 2 grade D and 1 grade C. Standard anterlor-posterior, lateral and flexion-extension radiographs, computed to- mography and MRI of cervical spine were obtained in all patients before operation. All patients presented with atlantoaxial dislocation, and the pathogenesis included disruption of transverse ligament（n=1）, atlantoaxial fracture and dislocation （n =1）, congenital odontoid malfromation （n =12）, atlantoaxial rotatory subluxation （n =2）. Cervical spinal cord compression was identified in 5 cases. The height of C1 posterior arch was 2.5-3.8mm （average, 3.0mm）. The atlanto-dental interval（ADI） was 6-14mm（average, 9mm）. Preoperative skull traction wasperformed rou-tinely on all cases for 1-2 weeks, and complete reduction was achieved in 7 cases, incomplete reduction in 5 cases, and no reduction in 4 cases. All patients had C1 pedicle screws placed as part of a fixation construct with pedicle exposure method（PEM）. C1-C2 pedicle screw placement under direct vision in- traoperativeiy, reduction and fixation, bone graft and fusion were administered in all cases. The neurological function and CT scan were used to evaluate the surgical outcome. Results： All 16 patients underwent bilater- al atlantoaxial pedicle screw fixation. All operations were completed successfully. A total of 64 screws were successfully placed. Reduction and fixation were suc