计算机辅助设计3D导航模板在儿童髋关节脱位Salter骨盆截骨手术中的应用

目的探究利用计算机辅助设计和3D打印技术制备导航模板,实现儿童发育性髋关节脱位Salter骨盆截骨髋臼方向精准定位的可行性。方法回顾性分析应用3D打印导航模板技术对2016年10月至2017年4月南京医科大学附属儿童医院骨科收治的12例单侧髋关节脱位行Salter骨盆截骨术患儿的临床资料。其中男4例,女8例;左侧5髋,右侧7髋;年龄1.5~5.0岁(平均2.3岁)。依据CT数据,使用Mimics软件将健侧髋关节镜像到对侧,将患侧髋关节行计算机辅助模拟Salter骨盆截骨术,旋转患侧髋关节与健侧髋关节镜像重合,根据术中可暴露的骨盆表面形态设计导航模板,通过快速成型技术打印模板,指导手术。比较术后患侧髋臼指数(AI)与术后健侧AI、患侧中心边缘角(CEA)与健侧CEA是否存在差异。结果通过12例髋关节脱位患儿,建立了制作Salter骨盆截骨术的个性化导航模板的方法。患儿手术时间为40.2~64.5 min[(50.6±8.5)min];术中出血量为35~60 mL,平均52 mL。患儿术后检查均未出现血管神经损伤,无一例患儿出现感染、导板异物残留等并发症。术前患侧AI[(38.4±2.8)°]与健侧AI[(21.6±0.8)°]比较,差异有统计学意义(t=-18.77,P<0.05);术前患侧CEA[(-5.8±12.6)°]与健侧CEA[(21.1±2.4)°]比较,差异有统计学意义(t=-7.348,P<0.05);术后患侧AI[(21.7±0.8)°]与健侧AI比较,差异无统计学意义(t=-2.037,P>0.05);术后患侧CEA[(21.2±2.6)°]与健侧CEA比较,差异无统计学意义(t=-0.435,P>0.05)。结论利用计算机辅助设计和3D打印技术制备的导航模板具有较好的准确性,为发育性髋关节脱位患儿行Salter骨盆截骨术中精准地行髋臼旋转提供了一种新的方法。

Application of computer aided design 3D printed navigation template in Salter pelvic osteotomy for dislocation of hip joint in children

Objective To explore the feasibility of accurate localization for the acetabular direction in Salter pelvic osteotomy for the developmental dislocation of the hip joint in children by using computer aided design and 3D printing technique.Methods The clinical data of 12 patients of unilateral hip dislocation treated with Salter pelvic osteotomy by using 3D printed navigation template in Department of Orthopedics,Children′s Hospital of Nanjing Medical University From October 2016 to April 2017 were retrospectively analyzed.Among the 12 cases,there were 4 males and 8 females,5 hips on the left and 7 hips on the right,aged 1.5 to 5.0 years old(mean 2.3 years old).According to the CT data,the models of the healthy hip joint were mirrored to the contralateral side by Mimics software.Computer-aided simulations of Salter pelvic osteotomy on models of the affected hip joints were performed.Then,the models of the affec-ted hip joint were rotated to the mirror models of the contralateral hip joint.The navigation templates were designed according to the exposed pelvic surface morphology during the operation.The navigation templates were printed by rapid prototyping technology to guide the operation.Preoperative and postoperative acetabular index(AI)and center edge angle(CEA)of affected side were compared to postoperative AI and CEA of contralateral side respectively.Results A method of making personalized navigation templates for Salter pelvic osteotomy was established in 12 children with developmental dislocation of the hip joint.The operation time ranged from 40.2 to 64.5 min,averaging(50.6±8.5)min.The intraoperative bleeding volume ranged from 35 to 60 mL,averaging 52 mL.No vascular and nerve injury was found in the postoperative examination,and no child had complications such as infection,residual foreign body of the guide plate and so on.There was significant difference in preoperative measurements regarding AI between the affected side[(38.4±2.8)°]and the contralateral side[(21.6±0.8)°](t=-18.77,P<0.05),and there was significant difference in preoperative measurements regarding CEA between the affected side[(-5.8±12.6)°]and the contralateral side[(21.1±2.4)°](t=-7.348,P<0.05).But there was no significant difference in postoperative mea-surements regarding AI between the affected side[(21.7±0.8)°]and the contralateral side(t=-2.037,P>0.05),there was no significant difference in postoperative measurements regarding CEA between the affected side[(21.2±2.6)°]and the contralateral side(t=-0.435,P>0.05).Conclusions The navigation template prepared by computer aided design and 3D printing technology has good accuracy,and is a new approach to accurate acetabular rotation in children with the developmental dislocation of the hip joint for Salter pelvic osteotomy.