Since the introduction of the first National Arthroplasty Register in Sweden in 1975, many other countries have tried to adopt the successful Scandinavian system. However, not all have overcome the political and practical difficulties of establishing a working register. We have surveyed the current registries to establish the key factors required for an effective database. We have received detailed information from 15 arthroplasty registers worldwide. The legal conditions under which they operate together with the methods of collection and handling of the data differ widely, but the fulfilment of certain criteria is necessary achieve a high degree of completeness of the data to ensure the provision of statistically relevant information.

Since the successful introduction of National arthroplasty registers by the Scandinavian countries, requirements in arthroplasty research have changed from pure implant survival rates to functional results and quality of life aspects. More patient data are required to address these areas. The goal of our international arthroplasty register survey was to determine key factors for an effective database as source for these scientific analyses.

In the first step, we identified and analysed all available arthroplasty registers via extensive literature and web searches. The preliminary data were validated by sending out a standardized questionnaire with questions regarding goals, organization, funding, documentation, data handling and output of the register. The responses were checked and, if necessary, further information requested via phone.

So far we received detailed information from nine arthroplasty registers worldwide. Only two registers collect data from clinical scores or questionnaires in addition to data for the survival rate. The majority of registers are maintained by the national orthopaedic associations, others like Finland by governmental organizations. The legal boundary conditions vary considerably, e.g. in Finland participation is mandatory, while patient tracking via Social security numbers is not possible in all countries. The rate of participating hospitals ranges up to 100%: 510 surgeons in Canada (72%) – 43 hospitals in Denmark (100%). The preferred locations are hip and knee, the preferred documentation method is paper-based, several registers offer online access or other types of electronic data transfer. In return, surgeons receive a regular feedback from the registers, mostly in form of annual reports. Only a few registers allow the surgeons to have online access to their data in the database. Funding is still of major concern. Although the definition of annual total costs varies, they stay far below 500,000 dollars. Examples of funding sources are the government, National Orthopaedic Associations, grants, a levy placed on the sale of implants, and others.

For the completeness of the collected data, a high rate of participating hospitals as well as a high follow-up-rate is crucial. This can only be guaranteed with substantial funding, governmental support for setting up an adequate framework and the compliance of the participating hospitals. New ways of data collection and processing might help to increase patient and hospital compliance.