Purpose The objective was to investigate the consistency in cumulative revision rates for a selection of total hip arthroplasty cups and stems across national/regional hip arthroplasty registries worldwide.

Methods Ten cups and 10 stems from total hip systems were randomly selected. Two frequently used implants across registries were added, totalling 11 cups and 11 stems. Cumulative revision rates (CRR) 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 10 cups and 8 stems from 8 registries, totalling 552,148 cups and 727,447 stems. Follow-up was 1-20 years. Five-year CRRs pooled on all cups was 2.9% (95%CI 2.3 to 3.6) and on all stems 3.0% (95%CI 2.4 to 3.8). Homogenous (consistent) CRRs with respect to both, associated implant and country, were observed for 2 cups and 3 stems. Significant differences in CRR were identified in 1 cup by associated implant only, in 1 cup by registry only, and in 2 cups and 4 stems for both. Sparse data prevented evaluation of 4 cups and 1 stem.

Conclusion Registries’ annual reports provide a large amount of publicly available information on CRRs of specific implants. These CRRs can be synthesized 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.

CC declares no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. JAS declares no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. CB declares no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. LAH declares no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. RN is currently secretary general of European Federation National Associations Orthopaedics and Traumatology (EFORT), and member of the chair registration board of Dutch Arthroplasty Register (LROI). PJM declares no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. AL declares no conflicts of interest. AL is the current president elect of the International Society of Arthroplasty Registries (ISAR). BB declares no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. CB declares no Competing Financial Interests and declares the following Non-Financial Interest: he is currently member of SIRIS hip & knee Scientific Advisory Board (Swiss Joint Registry) ML declares no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. KM declares no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. OM declares no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. RH declares no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. AS is contract holder for the analysis of the National Joint Registry of England, Wales and Northern Ireland. AS is unpaid co-chair of the ISAR Benchmarking working group. LNS declares no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

https://osf.io/6gmyx

This study was supported by a Horizon 2020 grant from the European Union (project number 965246).

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Members of the arthroplasty registry group: Barbara Bordini, Medical Technology Lab, IRCCS - Istituto Ortopedico Rizzoli, Bologna, Italy

Christian Brand, Institute of Social and Preventive Medicine (ISPM), University of Bern, Switzerland

Michelle Lorimer, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia

Keijo Mäkelä, Department of Orthopaedics and Traumatology, Turku University Hospital and University of Turku, Finland, and the Finnish Arthroplasty Register

Oliver Melsheimer, German Arthroplasty Registry (EPRD Endoprothesenregister Deutschland), Berlin, Germany

Richard Hughes, Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA

Adrian Sayers, Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical School, Southmead Hospital, Bristol, UK

Liza N. van Steenbergen, Dutch Arthroplasty Register, The Netherlands

All data analyzed in this studies are publicly available in the annual reports of arthroplasty registries.