基于三维反求技术和计算机辅助技术的3D打印导板在全膝关节置换术中的初步应用

Inteiligentized surgery based on 3D printing technology for personalized total knee arthroplasty

目的探讨基于三维反求技术和计算机辅助技术的3D打印导板在全膝关节置换术（TKA）中的初步应用效果。方法回顾性分析2014年8月至2015年9月期间利用3D打印导板辅助治疗的16例（18膝）行TKA术的患者（3D组）和采用传统TKA术的18例（18膝）（对照组）患者资料。3D组患者术前采用薄层CT扫描对下肢进行医学图像数据采集，然后利用三维反求技术进行骨骼的三维重构，通过计算机辅助设计技术进行导航模板的设计，再采用3D打印技术制造个性化手术导航模板，并进行TKA术。评估两组患者的手术截骨时间、引流量、凝血功能情况，并采用影像学评价下肢力线和假体位置。术后随访评估膝关节美国特种外科医院（HSS）评分及关节活动度（ROM）等。结果所有患者术后获4～15个月（平均9个月）随访。3D组术中导航模板与股骨髁、胫骨平台骨性解剖结构贴合紧密，无明显移动。3D组患者术后下肢力线偏差均〈3°。3D组与对照组术后伤口引流量中位数分别为375、613mL，差异有统计学意义（P〈0．05）。3D组与对照组手术截骨时间平均分别为（34．8±2．1）、（34．6±2．8）min，纤维蛋白原平均分别为（4．1±0．6）、（4．2±0．6）g／L，凝血酶原时间平均分别为（12．9±1．3）、（12．5±1．2）s，末次随访时3D组与对照组HSS评分平均分别为（86．5±4．5）、84．8±4．9分，以上项目组间比较差异均无统计学意义（P〉0．05）。术前与末次随访比较，3D组HSS评分由（27．3±4．8）分提高至（86．5±4．5）分，膝关节ROM由72．5°±9．1°提高至105．4°±6．8°，差异均有统计学意义（P〈0．05）。结论基于三维反求技术、计算机辅助设计技术和3D打印技术的3D打印导板能够准确重建患者下肢骨骼三维模型、精确定位下肢相关轴线，TKA假体力线可最大限度符合人体的生物力线要求。

Objective To investigate the application of 3D printed navigation template in personalized total knee arthroplasty （TKA） based on three-dimensional reverse engineering and computer-aided technology. Methods From August 2014 to September 2015, 16 patients （18 knees, 3D group） underwent personalized TKA aided by 3D printed navigation template and the other 18 patients （18 knees, control group） received conventional TKA. In the 3D group, 16-slice spiral CT was performed preoperatively for data collection. The DICOM format data obtained were imported into 3D design software in-house developed software Arigin3D Pro. After pre-processing and 3D reconstruction, 3D models of the patients＇ knees were generated and surgery navigation models designed in Arigin Surgical Templating. The model data of surgery navigation templates were then converted into STL format and fabricated by a 3D printer. At last, the surgery navigation templates were applied in the personalized TKA. The 2 groups were compared in terms of osteotomy time, postoperative drainage, blood clotting, alignment of the lower limb, prosthetic position, Hospital for Special Surgery （HSS） scores, and rage of motion （ROM）. Results All the patients were followed up for an average of 9 months （from 5 to 15 months）. In the 3D group, the navigation templates all contacted closely the bony structures of femoral condyle and tibial plateau, with no displacement, and all the deviations in alignment of the lower limb 〈 3°. The mean postoperative drainage in the 3D group （375 mL） was significantly less than that in the control group （613 mL） （ P 〈 0. 05）. There were no significant differences between the 3D group and the control group in osteotomy time （34.8 ± 2. 1 minutes versus 34.6 ±2.8 minutes）, fibrinogen （4. 1 ±0. 6 g/L versus 4. 2 ±0.6 g/L）, prothrombin time （ 12. 9 ±1.3 seconds versus 12.5±1.2 seconds）, or HSS score at the last follow-up （86.5 ±4. 5 points versus 84.8 ±4. 9 points） （ P 〉 0. 05） . Comparisons between the preoperation and the last follow-up showed that in the 3D group the HSS score significantly increased from 27.3 ± 4. 8 to 86.5± 4.5, and the ROM from 72. 5° ±9. 1° to 105.4° ±6.8° （ P 〈 0.05） . Conclusion Application of 3D printed navigation template in personalized TKA based on three-dimensional reverse engineering and computer-aided technology can precisely reconstruct the three-dimensional models of the bony structures of the lower limb, precisely localize the mechanical axis of the lower limb, and make the alignment of the implanted prosthesis maximally meet the biomechanical requirements of human body.