Development of a testing method for the determination of interfacial micromotions of short-stemmed hip endoprosthesis.

Short stemmed hip endoprostheses represent a relevant alternative to standard sized total hip stems. Especially in terms of bone stock preservation and minimal invasiveness the reduced length of such implants is beneficial. However, the smaller implant size is linked to a reduced surface geometry and thereby bone-implant-interface to provide implant stability. In order to evaluate the interfacial micromotions of a short stem implant experimentally a new measurement device was developed and validated with an optical system.