CLEARANCE DEFINITION FOR MONOLITHIC CERAMIC SHELLS: A CUSTOMIZED TOOL

Introduction The successful performance of ceramic on ceramic bearings in today's THA can mainly be addressed to the excellent tribological behaviour and the minimal wear of ceramic bearings. The clearance between head and shell plays a major role in this functionality of artificial hip joints. Knowledge about the deformation behaviour of the shell during implantation but also under daily loads is essential to be able to define a minimum clearance of the system. The aim of this work is to establish a tool for determining maximum ceramic shell deformation in order to predict minimum necessary clearance between heads and monolithic ceramic shells. Materials and Methods In order to determine the minimum clearance the following in vivo, in vitro and in silico tests were taken into account: Eight generic metal shells were implanted into cadaveric pelvises of good quality bone realizing an underreaming of 1 mm. Maximum deformation of the metal shells (um) after implantation were determined using an validated op...