On agile manufacturing of custom hip stems

摘要

Custom hip stems are preferred to standard shapes for total hip replacement when the patient's anatomy is outside common limits and / or cement-less systems are necessary. An integrated approach for developing a custom hip stem manufacturing system with flexibility and fast response to 'orders' is presented in this paper. The general framework is identified first. Work conducted so far on material selection involves experiments using Ti-6A1-4V or alumina on the stem and UMWPE on the cup in order to identify wear evolution with time and friction coefficient. Work on CAM consists of parametric modelling of the uncut block regions for fast rough cutting, optimisation concepts for z-heights of cut slices and design of experiments-based cutting condition and roughing strategy selection.