经口咽前路复位钢板固定技术用于儿童寰枢椎内固定的CT解剖学研究

Anatomic research on atlantoaxial reduction and plate fixation via transoral approach in children

目的 研究经口咽前路复位钢板（TARP）固定技术用于儿童寰枢椎内固定的可行性.方法 收集2010年1月至2012年12月年龄为5～15岁的儿童寰枢椎完整CT影像资料30套,男15例,女15例;平均年龄（8.9±3.6）岁.将儿童按年龄段分为5～9岁组（15例）和10 ～ 15岁组（15例）.采用影像归档和通信系统软件测量儿童CT上的寰椎侧块横、纵径、侧块内、外高、侧块宽度,虚拟的寰椎钉道长度、钉道外展角,枢椎椎体螺钉钉道长度、逆向椎弓根钉钉道长度、逆向椎弓根钉外展角等数据. 结果 两组儿童的寰椎侧块宽度及高度均满足3.5 cm螺钉置入要求,但5～9岁组儿童的钉道长度[（13.9±2.8）mm]小于10～15岁组[（15.9±2.8）mm],差异有统计学意义（t=2.487,P=0.033）;两组儿童寰椎钉道外展角度分别为12.4°±2.9°和12.0°±3.9°,差异无统计学意义（t=1.546,P=0.136）.5～9岁组儿童的枢椎椎弓根宽度＞3.5mm的比率[46.7％（7/15）]、枢椎椎体螺钉钉道长度[（10.8±2.5） mm]和逆向椎弓根螺钉钉道长度[（17.0±2.0）mm]均小于10 ～ 15岁组[73.3％（11/15）、（11.9 ±2.7）mm和（20.9±2.3）mm],差异均有统计学意义（P＜0.05）. 结论 对5 ～9岁儿童采用TARP固定技术基本可行,但10～15岁组儿童可以获得更佳的钉道长度.对儿童具体施术时,应该在术前薄层CT扫描图像上仔细测量后,设计个性化的置钉方式,以利于手术的安全和顺利实施.

Objective To investigate the feasibility of using transoral anterior reduction plate （TARP） for the atlantoaxial reduction and fixation in pediatric patients.Methods 30 complete sets of cervical CT scan images were obtained from the pediatric patients who had been treated in our department from January 2010 to December 2012.They were 15 boys and 15 girls,with an age range of 5 to 15 years （mean,8.9 ±3.6 years）.The children were divided into group A （15 cases,from 5 years old to 9 years old） and group B （15 cases,from 10 years old to 15 years old）.The following parameters were measured using tools in the PACS software：transverse and longitudinal diameters,inner and outer heights and width of atlas lateral mass,length of virtual atlas screw path,outward angle of atlas screw,length of axis screw,length of reverse axis pedicle screw,and outward angle of axis reverse pedicle screw.Results The size of lateral mass in both groups could accommodate a 3.5 mm screw.The length of screw path in group A （13.9 ±2.8 mm） was significantly shorter than that in group B （15.9 ± 2.8 mm） （t =2.487,P =0.033）.The outward angle of atlas screw in group A （12.4° ± 2.9°） was not significantly different from that in group B （12.0° ± 3.9°） （t =1.546,P =0.136）.Group A exhibited a significantly smaller proportion of pedicle width 〉 3.5 mm [46.7 % （7 / 15）],a significantly shorter length of pedicle screw （10.8 ± 2.5 mm） and a significantly shorter length of reverse axis pedicle screw （17.0 ± 2.0 mm） than group B [73.3% （11/15）,11.9 ± 2.7 mm and 20.9 ± 2.3 mm,respectively] （P 〈 0.05）.Conclusions It is basically feasible to use TARP for atlantoaxial reduction and fixation in pediatric patients from 5 to 15 years old,but older children allow for a longer screw path than younger ones.An individualized screw placement is advised when placing screws via transoral approach in pediatric patients.