This paper describes the ongoing development of a region-wide system for monitoring the short-term outcomes of total knee replacement surgery. The system aims to collect data from a dozen hospitals, and relies on a close collaboration with locally based surgeons and medical audit staff. The intention is to provide routine comparative information based on a broad conception of outcome, that includes both clinical/technical measures and patient-derived assessments of general health status. These data may be reported in the context of relatively detailed case mix information. To date, both data capture and clinical support for the project have been good. Example reports are presented together with a discussion of current limitations and possible future developments.