Background and purpose — Pooling data on the performance of total knee (TK) implants across registries is only possible if the same TK implant is used across multiple registries and if used in patients with similar characteristics. We assessed to what extent specific TK implants: (i) are used across multiple registries or only in a single registry; and (ii) differ in patient characteristics between registries. Methods — All primary TK implants implanted between January 2020 and December 2021 in the Danish, Dutch, German, and Italian registries were included. We determined the number of registries using a specific TK implant (based on combined femoral-tibial component brand name and fixation/congruency/mobile bearing insert/patella usage). Patient characteristics (age/body mass index [BMI]/sex/ diagnosis osteoarthritis) were compared across registries for TK implants used in ≥ 2 registries ≥ 100 times. Results — 813 different TK implants (577,351 procedures) were used across the 4 registries, of which 53 TK implants (7%) were used in 1 registry (8,000 procedures). 760 different TK implants (569,351 procedures; 99%) were used in ≥ 2 registries of which 47 different TK implants (393,954 procedures; 68%) were used in ≥ 2 registries and ≥ 100 times. Statistically and clinically significant differences in age for the same TK implant across registries were observed for 29 TK implants (62%) and 3 TK implants (6%), respectively; for other characteristics these were for BMI 30 (64%) and 0 (0%) TK implants; for male proportion 23 (49%) and 17 (36%) TK implants; and for diagnosis of osteoarthritis 42 (89%) and 34 (72%) TK implants, respectively. Conclusion — Most specific TK implants and TK procedures were used across multiple registries, but they were often used in patients with different characteristics. This has an impact on comparing implant performances between registries.

Objectives Medical device registries in Europe report limited information about their structure and methodological characteristics. This hinders their utility for evaluation of medical device safety and performance under the Medical Device Regulation. This study aimed to define a minimum checklist of items necessary for regulators to assess the quality of evidence produced using registry data for the evaluation of medical device safety and performance. Design A three-round Delphi panel. Setting A task within the Coordinating Research and Evidence for Medical Devices project. Participants 101 experts in the medical device community (healthcare professionals, methodologists, registry experts, regulators, and assessors from notified bodies) were invited. Interventions Based on a literature review and expert advice, 27 items relating to the quality of registry data and the analysis of medical device safety and performance were selected. In round 1, participants selected which items were required for a minimum checklist. They could also propose new items. Items selected by ≥70% of participants indicated consensus. Remaining items were discussed in round 2, resulting in a final checklist that was ranked by participants for importance (round 3). Main outcome measures Consensus of items to be included in the minimum checklist. Results 51 experts participated in round 1, achieving consensus on 18 (67%) items and suggesting 12 items. After discussion in round 2, 5 additional items were selected, resulting in a final set of 15 data quality items and 8 data analysis items. The most important items were ‘completeness of procedures’ (data quality) and ‘definition of outcome analyzed’” (quality of analysis). Conclusions Reporting all items from the minimum checklist will facilitate judgment of the utility of registry data to evaluate medical devices during post-market surveillance.

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: Orthopaedic Data Evaluation Panel (ODEP) ratings of total hip (TH) and total knee (TK) implants are informative for assessing implant performance. However, the validity of ODEP ratings across multiple registries is unknown. Therefore, we aimed to assess, across multiple registries, whether TH and TK implants with a higher ODEP rating (i.e., an A* rating) have lower cumulative revision risks (CRRs) than those with a lower ODEP rating (i.e., an A rating) and the extent to which A* and A-rated implants would be A*-rated on the basis of the pooled registries’ CRR. Methods: Implant-specific CRRs at 3, 5, and 10 years that were reported by registries were matched to ODEP ratings on the basis of the implant name. A meta-analysis with random-effects models was utilized for pooling the CRRs. ODEP benchmark criteria were utilized to classify these pooled CRRs. Results: A total of 313 TH cups (54%), 356 TH stems (58%), 218 TH cup-stem combinations (34%), and 68 TK implants (13%) with unique brand names reported by registries were matched to an ODEP rating. Given the low percentage that matched, TK implants were not further analyzed. ODEP-matched TH implants had lower CRRs than TH implants without an ODEP rating at all follow-up time points, although the difference for TH stems was not significant at 5 years. No overall differences in CRRs were found between A* and A-rated TH implants, with the exception of TH cup-stem combinations, which demonstrated a significantly lower CRR for A*A*-rated cup-stem combinations at the 3-year time point. Thirty-nine percent of A*-rated cups and 42% of A*-rated stems would receive an A* rating on the basis of the pooled registries’ CRR at 3 years; however, 24% of A-rated cups and 31% of A-rated stems would also receive an A* rating, with similar findings demonstrated at longer follow-up. Conclusions: At all follow-up time points, ODEP-matched TH implants had lower CRRs than TH implants without an ODEP rating. Given that the performance of TH implants varied across countries, registries should first validate ODEP ratings with use of country-specific revision data to better guide implant selection in their country. Data source transparency and the use of revision data from multiple registries would strengthen the ODEP benchmarks.

Background and purpose — Safety notices for medical devices such as total knee arthroplasty (TKA) implants may indicate problems in their design or performance that require corrective action to prevent patient harm. Safety notices are often published on national Ministries of Health or regulatory agencies websites. It is unknown whether problems triggering safety notices identify the same implants as those identified by registries as “outlier.” We aimed to assess the extent to which safety notices and outlier identification in registries signal the same or different TKA implants. Methods — The CORE-MD tool, an automated web scraper tool, was used to collect safety notices related to TKA implants on 13 national Ministries of Health websites and regulatory agencies. Safety notices were defined accord-ing to the Medical Device Regulation (MDR) as “a com-munication sent by a manufacturer to users or customers in relation to a field safety corrective action.” Identified TKA outliers, defined as having a significantly higher revision risk than other comparable TKA implants, were extracted from registry reports. Results — 787 safety notices for 38 TKA implants and 35 TKA outliers were identified, together identifying 47 unique TKA implants. 26 (55%) TKA implants had safety notices and were also outliers, 12 (26%) TKA implants had only safety notices, and 9 (19%) were outliers only. TKA implants with safety notices only had similar types of problems to TKA outliers with safety notices, with “Manufac-turing/Packaging/Shipping” problems being most frequent (44%). Cumulative revision risks (1/5/10 years) were lower for TKA implants with safety notices only than for TKA out-liers with safety notices. Conclusion — 55% of the TKA with a safety notice were identified as outliers in the registry, whereas around 25% of TKA outliers are not the subject of publicly released safety notices, with safety notices pointing to TKA implants not identified by registries as potentially having a higher risk of failure. This suggests that safety notices and registry outlier data measure different aspects of safety and performance.

In the European Union (EU) the delivery of health services is a national responsibility but there are concerted actions between member states to protect public health. Approval of pharmaceutical products is the responsibility of the European Medicines Agency, whereas authorizing the placing on the market of medical devices is decentralized to independent 'conformity assessment' organizations called notified bodies. The first legal basis for an EU system of evaluating medical devices and approving their market access was the medical device directives, from the 1990s. Uncertainties about clinical evidence requirements, among other reasons, led to the EU Medical Device Regulation (2017/745) that has applied since May 2021. It provides general principles for clinical investigations but few methodological details-which challenges responsible authorities to set appropriate balances between regulation and innovation, pre- and post-market studies, and clinical trials and real-world evidence. Scientific experts should advise on methods and standards for assessing and approving new high-risk devices, and safety, efficacy, and transparency of evidence should be paramount. The European Commission recently awarded a Horizon 2020 grant to a consortium led by the European Society of Cardiology and the European Federation of National Associations of Orthopaedics and Traumatology, that will review methodologies of clinical investigations, advise on study designs, and develop recommendations for aggregating clinical data from registries and other real-world sources. The CORE-MD project (Coordinating Research and Evidence for Medical Devices) will run until March 2024; here we describe how it may contribute to the development of regulatory science in Europe.