Outcome after total hip arthroplasty Part I.: General health evaluation in relation to definition of failure in the Swedish National Total Hip Arthroplasty register

The Swedish National Total Hip Arthroplasty register, which was started in 1979, is one of the oldest national quality registers in the world and consists of over 160,000 primary operations and 12,500 revisions. The register identifies risk factors for poor outcomes related to the patient, implant and surgical techniques. The end-point for failure, i.e., revision, dues not provide information about the patient's general health after the primary procedure. The aim of this study was twofold. First, to validate the end-point for failure in the Swedish National Total Hip Arthroplasty register and secondly, to study general health after total hip arthroplasty. We validated the outcome of 1,056 primary THRs randomly selected from the Discharge register in Sweden by comparing the data to the Swedish THA register. These patients had answered the SF-36 and Nottingham Health Profile questionnaires. By comparing the clinical outcome, measured as general health, with the results obtained from the register, we evaluated the importance of the end-point for failure. We found that the end-point was useful, but further evaluations are desirable. Patients operated on with hip replacement do very well up to 10 years postoperatively and those who are not revised have good general health. The findings in this study can be used as a reference for others as it shows results from a national register, with a random selection of the study cohort.