Gao Yongchang, Chen Zhenxian, Zhang Zhifeng, Chen Shibin, Jin Zhongmin
National Engineering Laboratory for Highway Maintenance Equipment, Chang'an University, 710064 Xi'an, Shaanxi, China.
State Key Laboratory for Manufacturing System Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, 710049 Xi'an, Shaanxi, China; Department of Arthroplasty Surgery, the Second Affiliated Hospital of Inner Mongolia Medical University, 010030 Hohhot, Inner Mongolia, China.
Clin Biomech (Bristol). 2018 Aug;57:48-55. doi: 10.1016/j.clinbiomech.2018.06.009. Epub 2018 Jun 12.
Steep inclination and excessive anteversion angles of acetabular cups could result in adverse edge-loading. This, in turn, increases contact pressure and impingement risk for traditional artificial hip joints. However, the influence of high inclination and anteversion angles on both the kinematics and contact mechanics of dual mobility hip implants has rarely been examined.
This study focuses on investigating both the kinematics and contact mechanics of a dual mobility hip implant under different inclination and anteversion angles using a dynamic explicit finite element method developed in a previous study.
The results showed that an inclination angle of both the back shell and liner ranging from 30° to 70° had little influence on the maximum contact pressure and the accumulated sliding distance of inner and outer surfaces of the liner under normal walking gait. The same results were obtained for an anteversion angle of the liner varying between -20° and +20°. However, when the anteversion angle of the liner was beyond this range, the contact between the femoral neck and the inner rim of the liner occurred. Consequently, this caused a relative rotation at the outer articulation.
This suggests that both inclination and modest anteversion angles have little influence on the kinematics and contact mechanics of dual mobility hip implants. However, too excessive anteversion angle could result in a rotation for this kind of hip implant at both articulations.
髋臼杯的陡峭倾斜度和过大的前倾角可能导致边缘负荷不良。这反过来又会增加传统人工髋关节的接触压力和撞击风险。然而，高倾斜度和前倾角对双动髋关节植入物的运动学和接触力学的影响很少被研究。
本研究使用先前研究中开发的动态显式有限元方法，重点研究双动髋关节植入物在不同倾斜度和前倾角下的运动学和接触力学。
结果表明，在正常步行步态下，后壳和内衬的倾斜角度在30°至70°范围内对内衬内外表面的最大接触压力和累积滑动距离影响很小。内衬前倾角在-20°至+20°之间变化时也得到了相同的结果。然而，当内衬的前倾角超出此范围时，股骨颈与内衬内缘之间会发生接触。因此，这导致了外关节处的相对旋转。
这表明倾斜度和适度的前倾角对双动髋关节植入物的运动学和接触力学影响很小。然而，过大的前倾角可能导致这种髋关节植入物在两个关节处发生旋转。
