The state of trial registrations in the field of Orthopaedics in years 2015–2020. A meta-epidemiological study

Objective: To assess the extent and trends in registration of Orthopaedic randomized clinical trials (RCTs) between 2015 and 2020. Design: Epidemiological study. Primary publications of RCTs published in top Orthopaedic journals (ISI Journal Citation Reports 2019 rankings) between 2015 and 2020 were included in this meta-epidemiological study with no restrictions on patient population, intervention/control groups or outcome type. Independent reviewers in pairs were involved in RCT selection and data extraction. The proportion of RCTs published that were registered (prospectively or retrospectively) or not registered were reported using counts and percentages stratified by years for each journal. Results: A total of 474 primary RCTs were considered eligible. We identified 157 out of 474 RCTs (33% of RCTs across journals) that were reported to have been registered prospectively.The proportion of prospective RCT registrations had increased by 40% (10%-50%) between 2015 and 2020. On the other hand, the proportion of RCTs with no registrations were reduced by 29% (50%-21%) between 2015 and 2020. Conclusion: Prospective RCT registration in the past 5 years in the field of orthopaedic has increased, but 2/3 of published RCTs still failed to report prospective registration.