Assessing the Completeness of Safety Reporting in Clinical Trials of Total Knee Arthroplasty: A Registry-Publication Comparison Study.

Background: Total knee arthroplasty (TKA) clinical trials inform surgical decisions by reporting adverse events (AEs), including serious adverse events (SAEs), other adverse events (OAEs), and deaths. However, concerns persist regarding discrepancies in AE reporting between trial registries, such as ClinicalTrials.gov, and peer-reviewed publications, even after the implementation of Food and Drug Administration Amendments Act Section 801 and the Final Rule of 2017, laws introduced to mitigate selective reporting and enhance public transparency. Methods: We conducted a systematic registry-to-publication comparison of 92 TKA-focused clinical trials with posted results on ClinicalTrials.gov between 2009 and 2024. Data on SAEs, OAEs, and deaths were extracted from registries and matched peer-reviewed publications using a pre-registered protocol. Descriptive statistics were used to evaluate discrepancies and trends over time. Regression analysis was used to assess the impact of the Final Rule and variables associated with changes in reporting score. Results: AE reporting was consistently more complete in ClinicalTrials.gov entries than in publications. SAE count mismatches were present in 95% of trials, and mortality data were omitted from 87% of pre-Final Rule Applicable Clinical Trial (ACT) publications. Post-Final Rule trials continued to underreport SAEs and deaths in publications, with no significant improvement in reporting completeness. Only 15% of trials listed AEs as formal outcomes in registries, and 66% of post-Final Rule ACTs omitted SAE reporting in the publication. Conclusion: Despite regulatory mandates, AE reporting in TKA trials remains inconsistent and incomplete across publications. These discrepancies risk undermining surgical decision-making and evidence-based guidelines. Enhanced enforcement, editorial accountability, and stricter adherence to reporting standards such as Consolidated Standards of Reporting Trials Harms are necessary to improve transparency and patient safety in orthopaedic research. Level of Evidence: Level II. See Instructions for Authors for a complete description of levels of evidence.