3D打印多孔钽金属髋臼加强块在成人DDH髋关节重建术中的应用

The application of 3D printed customized porous tantalum acetabular patch for adult DDH hip reconstruction

目的探讨应用3D打印技术制备的个体化多孔钽金属髋臼加强块进行髋关节重建术治疗成人发育性髋关节发育不良 （developmental dysplasia of the hip, DDH ）的可行性、安全性及疗效。方法2017年1月至2017年9月，应用3D打印个体化多孔钽金属髋臼加强块进行髋关节重建术治疗成人CroweI型DDH患者8例，男2例，女6例；年龄33-58岁，平均（43．75±7．81）岁。利用计算机对患者髋关节进行个体化三维建模，通过软件设计最合适大小的髋臼加强块，行多孔化处理，经有限元分析确保其符合生物力学要求后进行3D打印，行喷砂、高温、消毒等后处理。通过髋关节前侧入路显露髋臼顶部，植入个体化髋臼加强块，记录手术时间、术中出血量及并发症发生情况。术后6周、3个月、6个月门诊随访，采用视觉模拟评分（visual analogscale，VAS）评估疼痛情况，采用Harris髋关节功能评分与步态分析评估髋关节功能，以髋关节正位X线片及CT扫描三维重建观察髋臼加强块的位置及髋关节骨关节炎的进展。结果手术时间平均（1．13±0．23）h；术中出血量平均（114．17±41．22）ml。全部病例获得随访，随访时间6-12个月，平均8．2个月。髋关节外侧中心边缘角（eentral edge angle，CE角）从术前9．83°±5．34°增加至术后即刻的32．67°±2．53°；前侧CE角由术前3．83°±2．79°增加至术后即刻的21．67°±1．87°；覆盖率由术前57．33％±7．97％增加至术后即刻的87．33％±4．56％。VAS评分由术前（2．92±0．79）分降低至末次随访的（0．83±0．72）分，Harris髋关节评分由术前（69．67±4．62）分提高至末次随访的（84．25±4．14）分，手术前后的差异均有统计学意义。步态分析结果表明患者的步速、步频、行走时髋关节活动度、膝关节活动度均优于术前。影像学检查提示钽金属髋臼加强块与髂骨之间紧密接触，无松动，骨关节炎无进展。结论3D打印个体化多孔钽金属髋臼加强块能够重建髋臼骨缺损，增加股骨头的包容度，延缓髋关节骨关节炎的进展，降低髋关节重建术难度，术后早期关节功能良好。

Objective To explore the feasibility, safety and efficacy of customized porous tantalum acetabular patch made by three-dimensional （3D） printing technique in treating adult developmental dysplasia of the hip （DDH）. Methods Eight adult patients with Crowe I type DDH （2 men and 6 women, with a mean age of 43.75±7.81 years, range 33-58 years） who were treated with 3D printed customized porous tantalum acetabular patch hip reconstruction from January 2017 to September 2017 were included. The 3D printing technique was used for reconstructing and designing the optimal acetabular patch for the personal- ized hip joint of each patient. The acetabular patch was subjected to porous processing and finite element analysis until the biome- chanical requirements were met. The 3D printing of porous tantalum acetabular patch and post-processing was subsequently per- formed. The acetabular patch was implanted through the anterior approach of the hip joint. The operative duration, intraoperative blood loss and complications were recorded. All the included patients were followed up at 1.5, 3 and 6 months postoperatively. Pain was assessed using the visual analog scale （VAS）, and the hip joint function was evaluated using the Harris score and gait analysis. The patients underwent anterior-posterior radiography and 3D computed tomography of the hip joint aiming to observe the position of the acetabular patch and osteoarthritis progression. Results The mean operative duration was 1.13±0.23 h, and the mean blood loss was 114.17±41.22 ml. All patients were followed up for 6 to 12 months, with an average of 8.2 months. The mean lateral central-edge angle and anterior central-edge angle ranged from 9.83°±5.34° preoperatively to 32.67°±2.53° postoper- atively and from 3.83°± 2.79° preoperatively to 21.67°± 1.87° postoperatively, respectively. The rate of acetabular coverage in- creased from 57.33%±7.97% preoperatively to 87.33%±4.56% postoperatively. The VAS and Harris scores ranged from 2.92±0.79 preoperatively to 0.83 ±0.72 postoperatively and from 69.67±4.62 preoperatively to 84.25 ±4.14 postoperatively with statisti- cally significant difference, respectively. The results of gait analysis showed that the step speed, stride, the range of motion of hip and knee were better than that preoperatively. The images suggested a close contact between the tantalum acetabular patch and the iliae bone without loosening and progress of osteoarthritis in hip joint. Conclusion 3D printed customized porous tantalum acetabular patch could reconstruct the defect of acetabular, increase the coverage, and delay the progress of osteoarthritis of the hip joint. This method could reduce the difficulty of hip reconstruction, and the patients could obtain better joint function at the early stage.