3D打印技术在复杂肿瘤膝关节股骨假体周围骨折翻修术中的应用

Application of 3D printing technology in reconstruction of an complex periprosthetic femoral fracture of tumor knee joint

目的:采用计算机三维重建技术对1例复杂的肿瘤膝关节股骨假体周围骨折患者进行术前设计和手术模拟,为解决肿瘤膝关节置换术后股骨假体周围骨折的问题探索出一条更为精准可行的方案。方法:选择1例32岁被诊断为肿瘤膝关节股骨假体周围骨折的女性患者为研究对象,将患者双侧下肢骨骼和假体分别进行三维重建。测量患侧骨折位置的长度、残余股骨长度、股骨假体近端顶点的位置、组配式假体各个部分及患侧股骨髓腔在各个位置的直径等重要参数。根据参数在原有假体基础上进行股骨柄和钉道的特殊设计,与患侧股骨进行计算机模拟组装,无误后按照三维文件找原厂家进行假体股骨柄组件及导向器的定制。采用SLA光固化树脂打印机打印剖开的患侧股骨的树脂模型,与定制的组件和导航器一并在患侧进行假体模拟植入,匹配成功后进行常规手术,术中取出骨水泥,按照术前设定的步骤进行股骨柄翻修,术中骨折缺损处采用同种异体骨板进行修补。观察患者手术前后X线、患者术中病理检测结果、术后康复功能和康复功能评分。结果:术前经计算机匹配成功,模型与假体模拟组装成功,导向器重新定制,术中成功按照术前设计实施手术。术后病理回报结果符合预判。X线对位、对线良好。术后1个月患者恢复正常行走和下蹲功能,患者MSTS93评分从术前0分提高到术后1个月14分。结论:对于复杂的肿瘤膝关节假体周围骨折,术前可以采用计算机三维重建进行手术设计和模拟,3D打印技术打印模型与假体进行手术模拟匹配,从而保证最佳的手术效果。

Objective：To perform the preoperative design and operative simulation for periprosthetic femoral fractures （PFF）in one patient with complex tumor knee replacement under assistance of three-dimensional （3D） printing technology,and to explore a more accurate and feasible way to restore the normal anatomy and function of this kind of patients.Methods：The female patient aged 32 years old diagnosed with PFF after an complex tumor knee replacement was selected.The CT images of the patient’s bilateral legs were collected and reconstructed.The bilateral femurs were virtually sliced and the important parameters at each location of both sides were recorded respectively.Novel femoral stem and nail paths were specially designed on the basis of original prosthesis according to these parameters. Then vitual assemble was made with the residual femur. The prosthetic femoral stem components and navigator were customized based on the 3D simulation results when no more errors were found.The residual femoral resin model,customized components and navigator were printed with an SLA 3D printer.The bone＆amp;nbsp;cement was taken out and newly designed femoral stem was implanted successfully according to the steps designed preoperatively.The preconcerted allograft bone plates were applied for patch of the bone defect.The pathological results,X-ray and functional scores were included in the observation indexes. Results： With the help of successfully preoperative computer matching,successfully printed bone model-prosthesis assemble and re-customized navigator,the operation was successfully performed.The postoperative alignment shown in the X-ray image was good.The patient was able to normally walk and squat one month after operation with a crutch.MSTS93 score was improved from 0 before operation to 14 only one month after operation.Conclusion：As for PFF of complex tumor knee joint,preoperative design and simulation with 3D printing technology may provide a more accurately and effectively operative outcome than traditional methods.