[Experiences with the German Endoprosthesis Register]

The German Endoprostheses Register started its documentation of primary and revision surgery on major joints in 1997. About 7000 primary arthroplasties and 1100 revisions on hip joints as well as 3000 primary arthroplasties and 250 revisions on knee joints are registered annually by 41 hospitals, which amounts to 60% in primary or 80% in revision surgery of the Swedish arthroplasty register. 95% of the revisions are performed on implants which have not been primarily operated on by the hospitals enrolled to the register, normally recruiting the classical "lost-to-follow-up-cases". Especially the removed implants show a conspicuous diversity of models. More than 10 specimens were removed in only 24 of 173 different types of hip-stems and 21 of 133 different types of hip-sockets. Thus, in order to cover not only a small number of types of implants by statistical analysis, large numbers of surgery have to be registered to yield case-numbers which can not be achieved by registers of small countries like the Scandinavian. Germany with approximately 1900 relevant clinical departments owns a slumbering potential that could easily be recruited.