金属外壳变形对陶瓷对陶瓷全髋关节置换术接触力学的影响。

The influence of metallic shell deformation on the contact mechanics of a ceramic-on-ceramic total hip arthroplasty.

作者信息

Qiu Changdong, Wang Ling, Li Dichen, Jin Zhongmin

机构信息

State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.

State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, Leeds, UK

出版信息

Proc Inst Mech Eng H. 2016 Jan;230(1):4-12. doi: 10.1177/0954411915614514. Epub 2015 Oct 27.

DOI:10.1177/0954411915614514

PMID:26511269

Abstract

Total hip arthroplasty of ceramic-on-ceramic bearing combinations is increasingly used clinically. The majority of these implants are used with cementless fixation that a metal-backing shell is press-fitted into the pelvic bone. This usually results in the deformation of the metallic shell, which may also influence the ceramic liner deformation and consequently the contact mechanics between the liner and the femoral head under loading. The explicit dynamic finite element method was applied to model the implantation of a cementless ceramic-on-ceramic with a titanium shell and subsequently to investigate the effect of the metallic shell deformation on the contact mechanics. A total of three impacts were found to be necessary to seat the titanium alloy shell into the pelvic bone cavity with a 1 mm diameter interference and a 1.3 kg impactor at 4500 mm s(-1) velocity. The maximum deformation of the metallic shell was found to be 160 µm in the antero-superior and postero-inferior direction and 97 µm in the antero-inferior and postero-superior direction after the press-fit. The corresponding values were slightly reduced to 67 and 45 µm after the ceramic liner was inserted and then modified to 74 and 43 µm under loading, respectively. The maximum deformation and the maximum principal stress of the ceramic liner were 31 µm and 144 MPa (tensile stress), respectively, after it was inserted into the shell and further increased to 52 µm and 245 MPa under loading. This research highlights the importance of the press-fit of the metallic shell on the contact mechanics of the ceramic liner for ceramic-on-ceramic total hip arthroplasties and potential clinical performances.

摘要

陶瓷对陶瓷轴承组合的全髋关节置换术在临床上的应用越来越广泛。这些植入物大多采用无骨水泥固定，即金属背衬壳被压配入骨盆骨。这通常会导致金属壳变形，这也可能影响陶瓷衬垫的变形，进而影响加载状态下衬垫与股骨头之间的接触力学。采用显式动态有限元方法对带钛壳的无骨水泥陶瓷对陶瓷髋关节置换植入过程进行建模，进而研究金属壳变形对接触力学的影响。发现以4500 mm s(-1)的速度使用直径为1 mm的干涉配合和1.3 kg的冲击器，将钛合金壳压入骨盆骨腔共需要三次冲击。压配后发现金属壳在前后上方向的最大变形为160 µm，在前后下方向的最大变形为97 µm。插入陶瓷衬垫后，相应的值略有降低，分别为67 µm和45 µm，加载后分别变为74 µm和43 µm。陶瓷衬垫插入壳体内后，其最大变形和最大主应力分别为31 µm和144 MPa（拉应力），加载后进一步增加到52 µm和245 MPa。本研究强调了金属壳的压配对陶瓷对陶瓷全髋关节置换中陶瓷衬垫接触力学及潜在临床性能的重要性。