3D打印导航模板在大龄DDH患儿股骨近端内翻旋转短缩截骨术中的应用

Application of three-dimensional printed navigation template in proximal femoral varus rotation and shortening osteotomy for elder children with developmental dysplasia of the hip

目的 利用逆向工程（reverse engineering,RE）和快速成型（Rapid prototyping,RP）技术设计制备一种适用于大龄发育性髋关节脱位（developmental dysplasia of the hip,DDH）患儿股骨近端内翻旋转短缩截骨术的导航模板.方法 对2014年6月至2014年12月收治的6例（6髋）大龄DDH患儿进行CT连续扫描,根据CT数据使用Mimics和Geomagic Design Direct软件,利用正逆向结合建模设计囊括股骨近端内翻、旋转、短缩截骨术全部手术参数及步骤在内的导航模板.通过熔积成型（fused deposition modeling,FDM）法RP技术生产实物模板,手术时首先将导航模板与股骨近端相吻合,置入导针后,沿导航模板进行截骨,撤离导板后利用导针为操纵杆进行内翻、旋转及短缩并插入对应钢板钉孔内,于导针针道依次旋人皮质螺钉完成手术.结果 术前规划、模拟手术及术中操作一致,平均手术时长18 min,最长21 min,最短14 min,手术时间及射线暴露次数大幅降低,术后随访12～18个月,根据Mckay临床疗效评定标准：优4（66.7％）、良1（16.7％）、可1（16.7％）,优良率达83.3％;SeverinX线评定标准：Ⅰ级5髋（83.3％）、Ⅱ级1髋（16.7％）,优良率达100％,无1例出现再脱位和股骨头缺血坏死等并发症.结论 利用RE和RP技术制作的导航模板应用于大龄DDH患儿股骨近端内翻旋转短缩截骨术,可以简化手术步骤、节约手术时间、提高手术精确性、确保手术疗效,为大龄DDH患儿精准医疗提供新方法.

Objective To use reverse engineering （RE） and rapid prototyping （RP） technology for designing a new navigation template and explore its.feasibility in proximal femoral varus rotation and shortening osteotomy for elder children with developmental dysplasia of the hip （DDH）.Methods Between June 2014 and December 2014,computed tomography （CT） scans were performed for 6 cases of DDH.Mimics ＆ Geomagic Design Direct software was used for designing a navigation template for including all operative parameters and steps for proximal femoral varus rotation and shortening osteotomy.Template generated by fused deposition molding （FDM） of RP technology was placed distally on proximal femur.After placing Kirschner wire,bone was cut along the navigation template.And Kirschner wire was utilized as a lever for insertion into screw hole of plate after template removal.And cortical screw was placed for completing operation.Results Intraoperative operation was consistent with preoperative measurements and simulation operation.The average operative duration was 18（14-21） min.Six patients （6 hips） were followed postoperatively for 12-18 months.According to the McKay criteria,the outcomes were excellent （n =4,66.7%）,good （n =1,16.7%） and fair （n =1,16.7%） with a fineness ratio of 83.3%.And based upon the Severin radiographic criteria,the outcomes were excellent （n=5,83.3%） and good （n =1,16.7%） with a fineness ratio of 100%.There was no onset of such major osteotomy-related complications as redislocation or avascular necrosis.Conclusions During proximal femoral Varus rotation and shortening osteotomy for elder DDH children,this novel navigation template may improve operative precision,simplify operative procedures and ensure efficacies.