Experimental Tribological Methods for Evaluating the Suitability of Materials for Hemiarthroplasty

Hemiarthroplasty is a partial joint replacement where one half of the joint is replaced, resulting in a cartilage-on-artificial-material articulation. With the development of novel joint replacement materials and coatings, there is a need to develop and standardise test methods to assess materials tribologically for use in hemiarthroplasty applications prior to implantation. Several different protocols and approaches with differing levels of complexity have been developed to study materials for use in hemiarthroplasty applications, but to date, no consensus has been reached as to the most appropriate method, or suite of methods, to use. The aim of this review article was to assimilate and critique published methods for tribologically evaluating hemiarthroplasty materials, to discuss advantages and limitations of the methods used, to highlight the variables that should be considered when developing new test methods and to identify gaps in the current literature. There is clearly a need to study materials and implants specifically for use in hemiarthroplasty applications and much research has been carried out in the field. However, for protocols to be standardised, there is a need for experts to converge on the most appropriate methodologies.