采用奇异值分解法定位膝关节置换过程中髓内杆的入针点  

Entry point of an intramedullary rod in knee arthroplasty:determined using singular value decomposition method

作　　者：汪震 胥义[1] 涂意辉 Wang Zhen;Xu Yi;Tu Yihui(School of Health Sciences and Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Department of Joint Surgery,YangpuHospital,Tongji University,Shanghai 200093,China)

机构地区：[1]上海理工大学健康科学与工程学院,上海市200093 [2]同济大学附属杨浦医院关节科,上海市200093

出　　处：《中国组织工程研究》2022年第18期2828-2833,共6页Chinese Journal of Tissue Engineering Research

基　　金：国家自然科学基金(51576132,52076140),项目负责人:胥义。

摘　　要：背景:在膝关节置换手术过程中,假体对线是一个手术要点,其对于植入物存活年限有着很大影响。髓内定位杆在术中假体植入对齐的作用已经得到了验证,髓内定位杆插入误差过大会增加假体植入失败和内侧骨塌陷的概率,髓内定位杆的插入路径依赖于解剖轴的确定。目的:通过计算机辅助的方式,基于奇异值分解法对解剖轴确定的方式进行改进,提高髓内定位杆的插入精度,延长假体的使用寿命。方法:对9例需要接受全膝关节置换患者的术前扫描CT图像进行处理,通过MIMICS RESEARCH 17.0对股骨进行三维重建。使用MATLAB2018b软件,通过奇异值分解方法对股骨解剖轴确定的方式进行改进,将模拟多点法拟合解剖轴髓内杆插入后的模型导入3-matic中进行误差角度的测量;并与传统方法(两点法拟合解剖轴)及推荐法髓内定位杆的插入进行模拟及验证比较。结果与结论:试验采用的多点法测量得出的内、外翻角度分别为(1.99±1.03)°,(2.35±1.34)°;前后部偏移角度(1.83±0.67)°,(1.60±1.82)°,与传统的临床手术方法比较,平均角度误差减小了0.41°,提升了定位精度。因此,文章所提出的方法有助于进一步提高全膝关节置换中假体对线的准确性,延长假体的使用寿命。BACKGROUND:During knee arthroplasty,prosthesis alignment is a key point,which has a great impact on the life span of implants.The role of an intramedullary rod in the intraoperative alignment of prostheses implanted has been verified.Excessive insertion error of the intramedullary rod will increase the probability of prosthesis implantation failure and medial bone collapse.Moreover,the insertion path depends on the determination of anatomical axis.OBJECTIVE:To improve the computer-aided method for positioning the anatomical axis based on singular value decomposition,so as to improve the insertion accuracy of intramedullary rod and prolong the life span of prostheses implanted.METHODS:We processed preoperative computed tomography images from nine patients scheduled for total knee arthroplasty,and reconstructed the three-dimensional model of the femur using MIMICS RESEARCH 17.0.MATLAB2018b software was subsequently used to improve the positioning of the anatomical axis of the femur using singular value decomposition method.Insertion of the intramedullary rod was simulated based on the anatomical axis fitted using multi-point method.After that,the model was introduced into 3-matic,and angle error was measured.Traditional method by which the anatomical axis was fitted by two-point method and the recommended method described above were compared and verified through the simulated insertion of the intramedullary rod.RESULTS AND CONCLUSION:The varus and valgus angles measured by the multi-point method were(1.99±1.03)°and(2.35±1.34)°,respectively.The anterior and posterior offset angles were(1.83±0.67)°and(1.60±1.82)°,respectively.Compared with the traditional surgical method,the recommended method could improve the positioning accuracy,by which the average angle error was reduced by 0.41°.Therefore,the recommended method described above helps further improve the accuracy of prosthesis alignment in total knee arthroplasty and prolong the lifespan of prostheses implanted.

关 键 词：膝关节置换术 髓内定位杆 奇异值分解法 三维重建 计算机辅助 

分 类 号：R459.9[医药卫生—治疗学] R496[医药卫生—临床医学]