LUBRICATION EFFECT OF METAL-ON-METAL IN HIP JOINT REPLACEMENT

Abstract

The consumption of hard-on-hard material is one of alternative methods to replace the soft-on-soft or soft-on-hard material which has long been used in hip joint replacement. The famous the type of hard-on-hard material in hip joint replacement is metal-on-metal. It is the best method which is selected by surgeon to replace the original hip joint. However, the metal-on-metal hip implants can be producing the smallest wear particle as a result of attrition of contact surface between femoral head and acetabulum cup. Therefore, the lubricant must be located between the surface of femoral head and acetabulum cup to reduce wear particle. Hence, an analysis is carried out to examine the effect of lubrication on metal-on-metal hip joint replacement upon the occurrence of contact surface between femoral head and acetabulum cup. It includes two types of analysis namely dry and lubrication contact analysis. Based on analysis in dry contact, the maximum contact pressure occurs at the surface of acetabulum cup, namely 32.887 MPa. For lubrication contact, the maximum contact pressure also occurs at the surface of acetabulum cup but its value was lower compared to another case. It was occurs because at the region between surface of femoral head and acetabulum cup have full fluid film lubrication. So, the wear that produced by metal-on-metal hip joint implants can be reduced. In addition, this project was more focuses to the effect of design parameters on the maximum contact pressure. It was involves two condition contact namely dry and lubrication contact. Based on the result of the effect of the radial clearance on contact pressure, it was found that the maximum contact pressure is increases when the radial clearance also increases. According to the result of the effect of the femoral head size, it was found that the maximum contact pressure is decrease when the femoral head size is increase