Purpose: The objective was to investigate the consistency in cumulative revision rates (CRRs) for a selection of total hip arthroplasty cups and stems across national/regional hip arthroplasty registries worldwide. • Methods: Ten cups and ten stems from total hip systems were randomly selected. Two frequently used implants across registries were added, totalling 11 cups and 11 stems. CRRs and 95% CIs were extracted from the latest annual registry reports using these implants. CRRs were pooled for each cup or stem, and differences between cup-stem combinations and between registries were investigated. • Results: CRRs were available for ten cups and eight stems from eight registries, totalling 552,148 cups and 727,447 stems. Follow-up was 1–20 years. The 5-year CRR pooled for all cups was 2.9% (95% CI: 2.3–3.6) and for all stems, 3.0% (95% CI: 2.4–3.8). Homogeneous (consistent) CRRs with respect to both associated implant and country were observed for two cups and three stems. Significant differences in CRR were identified in one cup by associated implant only, in one cup by registry only, and in two cups and four stems for both. Sparse data prevented evaluation of four cups and one stem. • Conclusion: Registries’ annual reports provide a large amount of publicly available information on CRRs of specific implants. These CRRs can be synthesised to improve the assessment of implant performance over time. Our CRR analysis represents a promising approach to detect implants with a consistent low- or high-risk pattern across registries.

Background and purpose — The amount of information publicly available from arthroplasty registries is large but could be used more effectively. This project aims to improve the knowledge concerning existing registries to facilitate access, transparency, harmonization, and reporting. Methods — Within the International Society of Arthroplasty Registries (ISAR) we aimed at developing, testing, adopting, and making publicly available a short, standardized registry description with items considered relevant for stakeholders using a cross-sectional study survey. Items were chosen based on a literature review and expert advice, selected by 9 ISAR working group members, tested iteratively in 3 registries, and commented upon by 4 external experts. All 29 ISAR member registries as of July 2023 were invited to participate in the project. Results — Included items covered general descriptive information regarding registries, information related to governance, outcomes, data quality, data access, and registry production. The template was adopted, completed, and made publicly available by 25 of the 29 registries. Of those, 2/3 were national registries. 23 captured both hip and knee arthroplasties and 10 captured shoulder arthroplasties. Most registries had public reporting of data quality, methods, and results. Data was accessible in all but 2 registries, mainly as aggregated data. Important items relevant to registry quality for researchers to consistently indicate in scientific papers include scope, inclusion criteria, outcomes definitions, coverage/completeness, and validation processes. Conclusion — This ISAR initiative implemented a short, standardized description to facilitate appropriate use of orthopedic registry data worldwide relevant for a diverse group of stakeholders including researchers, industry, public health and regulatory agencies.