Total hip arthroplasty (THA) implantation tends to increase. Measurement of outcomes allows assessment of the success and failure of THA. Outcomes after THA can be measured by clinical scores and questionnaires, radiological findings, complications, implant survival, or mortality.

The systematic collection of data within the Geneva Arthroplasty Registry (GAR), and the analysis of these data, allows patients to be provided with information on the prognosis, to understand what influences outcomes and take steps to optimize the perioperative period, and surgery can be planned in light of current knowledge. In this way, outcomes can be improved.

To improve them, we need to understand the influence of patient- and surgery-related characteristics on outcomes; some of these characteristics can be modified, while others cannot.

Our research showed that smoking negatively influenced the risk of infection after total hip or knee arthroplasty. Education level influenced postoperative scores and resource utilization one year after THA. Regarding surgery and in particular implants, the use of a dual-mobility cup compared to a unipolar cup positively influenced the risk of dislocation 6 months after THA. Finally, after 10 years of follow-up, small head metal-on-metal THAs had higher revision rates compared to ceramic-on-polyethylene THAs.

To conclude, outcomes after THA are influenced by patient- and surgery-related characteristics. Longitudinal follow-up of patients undergoing THA within the GAR allows for the assessment of interactions between patient- and surgery-related characteristics, the evaluation of changes implemented in response to research findings, and the monitoring of implants