计算机辅助设计联合3D打印技术在评估DDH髋关节匹配中的应用

The Application of Computer Aided Design and 3D Printing Technology in the Evaluation of Hip Joint Matching of DDH

目的:探讨发育性髋关节脱位患儿术前虚拟手术设计中髋关节匹配的相关研究,指导髋关节手术术式选择。方法:选取2013年1月至2015年1月10例发育性髋关节发育不良(DDH)患儿,行骨盆正位片、双侧髋关节CT扫描,利用双髋关节CT数据,通过Mimics14.0重建出仿真性高的骨性髋关节数字模型,CT扫描髋关节拼接图像,Mimics14.0重建高仿真髋关节模型,通过3D打印高分子发育不良骨盆和股骨模型,术前比较骨盆模型髋臼指数、髋臼深度与股骨头直径比值,评价髋关节覆盖程度与匹配程度;术后进行双髋关节CT检查,并与术前设计进行比较,评价应用效果,指导术式设计。结果:术前骨盆三维模型髋臼指数平均值34.53°±0.46°,术后骨盆髋臼指数平均值20.75°±0.36°,P<0.05,存在显著性差异。术后双侧髋关节CT显示,术前骨盆与股骨3D模型模拟手术方式合理,术后随访24个月效果良好。结论:骨盆与股骨三维重建模型评估髋关节匹配更接近实际要求,利用骨盆与股骨三维重建的数字模型进行术前模拟、指导术式设计、缩短手术时间。

Objective:To explore the related researches on hip joint matching in the virtual surgery design of children with DDH before surgery,and guide the choice of surgical method of hip joint surgery.Methods:10 children with developmental dysplasia of hip(DDH)from January 2013 to January 2015 are selected.Anteroposterior film of pelvis is obtained,and CT scan of bilateral hip joints is completed.By using the CT data of both hip joints,the high-simulation digital model of bony hip joint is reconstructed by Mimics14.0,the mosaic image of hip joint is scanned by CT,the high-simulation hip joint model is reconstructed by Mimics14.0,and the high molecular dysplastic pelvis and femur model is printed by 3 D printing.The acetabular index of the pelvis model and the ratio of depth of the acetabulum and diameter of femoral head are compared before surgery,and the coverage and matching degree of hip joint is evaluated.CT examination of both hip joints is made after surgery,and comparation is made with the preoperative design to evaluate the application effect and guide the design of surgical method.Results:The average acetabular index of the three-dimensional model of pelvis is 34.53°±0.46°before surgery and 20.75°±0.36°after surgery(P<0.05).There is significant difference.CT of bilateral hip joints after surgery shows that the simulated surgery of 3 D model of pelvis and femur before surgery is reasonable and the effect is good in 24 months of follow-up after surgery.Conclusion:The evaluation of hip joint matching by three-dimensional reconstruction model of pelvis and femur is closer to the actual requirement.Use of the digital model of three-dimensional reconstruction of pelvis and femur for preoperative simulation and guidance of the design of surgical method can effectively guide the design of surgical method and reduce the surgery time.