儿童S2髂骨螺钉置钉可行性分析及钉道规划

Feasibility analysis and nail planning of S2 iliac crest screw placement in children

目的:利用计算机三维重建及模拟置钉技术评估S2髂骨螺钉在国人儿童应用可行性,且优化测量其钉道参数。方法:选取2018年12月至2020年12月行骨盆CT扫描且年龄5~16岁的儿童骨盆影像学资料83例,排除骨折、畸形、肿瘤等情况,其中男44例,女39例,年龄(10.66±3.52)岁,依据年龄分为4组(A组5~7岁;B组8~10岁;C组11~13岁;D组14~16岁)。将获得的原始CT数据导入Mimics软件中,三维重建骨盆骨性结构,并在三维视图模拟分别以螺钉最大头倾角、最小头倾角置入直径6.5 mm S2髂骨螺钉。随后在3-Matic软件中分别测量最大头倾角和最小头倾角下螺钉冠状位夹角、矢状位尾倾角、横断位外展角、置钉总长度、骶骨内螺钉长度、髂骨宽度、进钉点距皮肤距离。比较分析不同年龄段儿童S2髂骨螺钉置钉参数间的差异及性别与左右侧别间差异。结果:83例儿童均可置入直径6.5 mmS2髂骨螺钉。各置钉参数左右侧别间比较,差异无统计学意义(P>0.05)。5~7岁儿童螺钉冠状位角度小于其他年龄段(P<0.05);但在螺钉矢状位角度上,在螺钉最大头倾角下5~7岁儿童可获得较大角度,但在最小头倾角下较大角度获得年龄组为11~13岁。螺钉横断位角度各年龄组差异无统计学意义(P>0.05)。5~7岁男童在最大头角下的冠状位角度和最小头倾角下的矢状位角度均大于女童(P<0.05);8~10岁女童最小头倾角下的冠状位角度大于男童(P<0.05);其余置钉角度参数男女性别间差异均无统计学意义(P>0.05)。各年龄组间,髂骨最小宽度、最长钉道距离及骶骨内螺钉长度差异随年龄增长,均呈增长趋势(P<0.05)。5~7岁及8~10岁女童皮肤距离均大于男性(P<0.05)。男童在14~16岁髂骨最小宽度宽于同阶段女童(P<0.05)。而5~7岁及11~13岁女童,最长钉道距离长于同阶段男童(P<0.05)。结论:5~16岁儿童骨盆可安全容纳直径6.5 mmS2髂骨螺钉置入,但是由于儿童骨盆骨性结构处于发育生长时期,需精准评估,规划合理钉道、选择合适螺钉长度。

Objective To evaluate the feasibility of S2 alar iliac screw insertion in Chinese children using computerized three-dimension reconstruction and simulated screw placement technique,and to optimize the measurement of screw parameters.Methods A total of 83 pelvic CT data of children who underwent pelvic CT scan December 2018 to December 2020 were retrospectively analyzed,excluding fractures,deformities,and tumors.There were 44 boys and 39 girls,with an average age of(10.66±3.52)years,and were divided into 4 groups based on age(group A:5 to 7 years old;group B:8 to 10 years old;group C:11-13 years old;group D:14 to 16 years old).The original CT data obtained were imported into Mimics software,and the bony structure of the pelvis was reconstructed,and the maximum and minimum cranial angles of the screws were simulated in the three-dimensional view with the placement of 6.5 mm diameter S2 alar iliac screws.Subsequently,the coronal angle,sagittal angle,transverse angle,total length of the screw,length of the screw in the sacrum,width of the iliac,and distance of the entry point from the skin were measured in 3-Matic software at the maximum and minimum head tilt angles,respectively.The differences among the screw parameters of S2 alar iliac screws in children of different ages and the differences between gender and side were compared and analyzed.Results In all 83 children,6.5 mm diameter S2 iliac screws could be placed.There was no significant difference between the side of each screw placement parameter.The 5 to 7 years old children had a significantly smaller screw coronal angle than other age groups,but in the screw sagittal angle,the difference was more mixed.The 5 to 7 years old children could obtain a larger angle at the maximum head tilt angle of the screw,but at the minimum cranial angle,the larger angle was obtained in the age group of 1l to 13 years old.There were no significant differences among the age groups.The coronal angle and sagittal angle under maximum cephalic angle and minimum cranial angle of 5 to 7 years old male were(40.91±2.91)°and(51.85+3.75)°respectively,which were significantly greater than in female.The coronal angle under minimum cranial angle was significantly greater in girls aged 8-10 years old than in boys.For the remaining screw placement angle parameters,there were no significant differences between gender.The differences in the minimum iliac width,the screw length,and the length of the sacral screws showed an increasing trend with age in all age groups.The distance from the screw entry point to the skin in boys were significantly smaller than that of girls.The minimum width of the iliac in boys at 14 to 16 years of age were significantly wider than that in girls at the same stage.In contrast,in girls aged 5 to 7 years and 11 to 13 years,the screw length was significantly longer than that of boys at the same stage.Conclusion The pelvis of children aged 5 to 16 years can safely accommodate the placement of 6.5 mm diameter S2 alar iliac screws,but the bony structures of the pelvis are developing and growing in children,precise assessment is needed to plan a reasonable screw trajectory and select the appropriate screwlength.