基于快速成型技术的个体化人工股骨髁关节面的设计与应用

A new custom-made artifical articular cartilage of femoral condyle based on rapid prototyping technique:a case report

目的 设计、制造一种基于快速成型技术、复合异体半关节移植的个体化人工股骨髁关节面 ,探讨解决异体半关节移植中异体关节软骨坏死和异体 自体关节形状不匹配的方法。方法对异体半关节和骨肿瘤患肢股骨髁外表面行螺旋CT扫描 ,将CT断层图像进行矢量转换后在Surfacer9 0软件进行矢量化三维重建 ,提取出合适的异体骨软骨下骨和患者关节软骨表面轮廓的三维图像 ,在计算机辅助下设计人工关节面 ,应用LPS6 0 0快速成型机制出快速成型树脂模型 ,以钛合金为材料铸造关节面假体主件 ,通过融合笼将关节面固定于关节上 ,抛光后获得人工关节软骨面成品。2 0 0 2年 2月对 1例男性 14岁右股骨下段骨肉瘤患者 ,行右股骨下段瘤段切除、人工股骨髁关节面复合大段同种异体骨移植重建股骨下端骨缺损术。结果 新型复合异体半关节移植的个体化人工股骨髁关节假体与异体骨、对侧关节匹配良好 ;应用后随访 16个月 ,膝关节功能良好。结论 个体化股骨髁关节面明显改善了异体半关节移植患者的膝关节功能 ,为异体半关节移植中存在的异体关节软骨坏死和异体

Objective To design and manufacture a new custom-made artifical articular cartilage of femoral condyle based on rapid prototyping technique and explore a method to solve the necroses of allocartilage in hemijoint allotransplantation. Methods Design the new custom-made artifical articular cartilage of femoral condyle. The allograft and the patient distal femurs were scanned with Picker 6000 spiral computed tomography (CT) with 1.0 slice thickness and pitch of 1.5, reconstructed the distal femurs in Voxel Q image workstation with volume rendering technique. Then downloaded the transaxial 2D image data to personal computer at 0.1 mm interval and converted it into 2D digitized contour data by using image processing software developed by our team. The 3D wire frame and solid images of femoral condyle could be reconstructed when the 2D digitized contour data were inputted into image processing software Surfacer 9.0 (Imageware Company, USA). Subsequently based on the clinical experience and the need of design, the 3D contour image of articular cartilage was extracted from the surrounding. Based on the extracted 3D contour image, the computer-aided design (CAD) of the custom-made artifical articular cartilage was accomplished in Surfacer software, converted the CAD model into RP data format .Standard triangularization language, imported into the LPS600 rapid prototyping machine (Hengtong Company, Xi'an Jiaotong University, China), and the resin prototype was achieved. Then the resin model was used as a positive mould to build up a silica gel negative mould, the negative mould was sent to the factory to manufacture Ti-6Al-4V alloy articular artilage through ordinary mould-melted founding process. Finally, the whole metal cartilage was completed after melting two special cages on it. A patient was selected to clinical applying. Results A new custom-made artifical articular cartilage of femoral condyle was made. It was press-fit well to the subchondral bone of the allograft bone. The patient′s one and half year follow-up result was excellent. Conclusions We design and manufacture a new custom-made artifical articular cartilage of femoral condyle based on rapid prototyping technique. The result shows that the manufacturing process has the advantage of rapidness and precision that are very important for individualized artificial implant manufacturing. The artificial articular cartilage is press-fit well and could be a good idea to solve the necroses of allocartilage in hemijoint allotransplantation.