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The effect of femoral head size on edge loading in metal‐on‐metal hip joint replacement under dynamic separation conditions
Author(s) -
Liu Feng,
Lian Chao,
Feng Li,
Wang Junyuan,
Du Wenhua
Publication year - 2020
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.34531
Subject(s) - materials science , joint (building) , enhanced data rates for gsm evolution , head (geology) , femoral head , rotation (mathematics) , structural engineering , composite material , engineering , anatomy , computer science , geology , medicine , telecommunications , geomorphology , artificial intelligence
Abstract Edge loading that occurs in hip joint replacements due to dynamic separation of the joint bearings has been shown to cause severe wear for meal‐on‐metal bearings. In the present study, the multibody dynamics model for metal‐on‐metal (MoM) hip joints with a medial–lateral translational mismatch in the centers of rotation of the cup and head has been developed to predict the dynamic separation and contact force of edge loading under gait loading conditions. The effects of larger head diameters (28–55 mm), in combination with the translational mismatch (0–4 mm) and varied cup inclination angles (45°–65°), on edge loading of MoM bearings have been computationally investigated. For the given translational mismatch, increasing head diameters results in negligible effects on the dynamic separation, contact force and severity of edge loading. Increasing head size also leads to increased offset loading torque which has been found to reach at the level that may cause cup loosening under larger translational mismatch at 4 mm. The result highlights the importance of the cup inclination angle of 45° and a lower translational mismatch to avoid severe edge loading.