Abstract

Evaluation of prosthetic components for total joint replacement has been attempted using a number of methods, most of which have defects. Clinical studies using scores have severe limitations; survivorship studies represent a fairly crude way of assessing new prosthetic components, and they require long periods of observation. Radiological evaluation is often subjective, as are most studies on component migration. There are fortunately alternative methods, such as roentgen stereophotogrammetric analysis, which give objective results within short delays; new methods are being developed which can provide similar information at a more reasonable expense. Illustrative studies are reported, and it is concluded that new components should be evaluated by measuring their early migration rate, which is shown to have a predictive value.