Aims The aim of this study was to determine the impact of the severity of anaemia on postoperative complications following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Methods A retrospective cohort study was conducted using the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) database. All patients who underwent primary TKA or THA between January 2012 and December 2017 were identified and stratified based upon hematocrit level. In this analysis, we defined anaemia as packed cell volume (Hct) < 36% for women and < 39% for men, and further stratified anaemia as mild anaemia (Hct 33% to 36% for women, Hct 33% to 39% for men), and moderate to severe (Hct < 33% for both men and women). Univariate and multivariate analyses were used to evaluate the incidence of multiple adverse events within 30 days of arthroplasty. Results Following adjustment, patients in the THA cohort with moderate to severe anaemia had an increased odds of 6.194 (95% confidence interval (CI) 5.679 to 6.756; p < 0.001) for developing any postoperative complication. Following adjustment, patients in the TKA cohort with moderate to severe anaemia had an increased odds of 5.186 (95% CI 4.811 to 5.590; p < 0.001) for developing any postoperative complication. Among both cohorts, as severity increased, there was an increased risk of postoperative complications. Conclusion Preoperative anaemia is a risk factor for complications following primary arthroplasty. There is a significant relationship between the severity of anaemia and the odds of postoperative complications. Patients who had moderate to severe anaemia were at increased risk of developing postoperative complications relative to patients with mild anaemia. When considering elective primary THA or TKA in a moderately or severely anaemic patient, surgeons should strongly consider correcting anaemia prior to surgery if possible. Cite this article: Bone Joint J 2020;102-B(4):485–494.

Introduction:Orthopaedic surgery residency applicants submit more applications than ever before. While this issue is multifactorial, increased information and transparency regarding residency programs are important. This study aimed to evaluate the completeness and variability of the information that is currently available regarding orthopaedic residency programs on two publicly available databases, the Fellowship and Residency Electronic Interactive Database (FREIDA) and the newly created Orthopaedic Residency Information Network (ORIN).Methods:Orthopaedic surgery residency programs were identified and evaluated using FREIDA and ORIN on September 11, 2021. Information on the FRIEDA and ORIN databases were evaluated in the following categories: program overview, the residency application, and education information. Univariate statistical analysis was performed on the data.Results:Of the 194 programs that participated in the FREIDA database, over 48% failed to include basic program information including resident demographics and key application information including USMLE Step requirements. Of the 141 programs that participated in the ORIN database, most the programs did not report USMLE Step median and cutoff scores and clerkship grades. Depending on the database and type of information, factors including the program's National Institutes of Health funding, reputation, size, and type were associated with the availability of information.Conclusion:This study showed that while most orthopaedic surgery residency programs participate in FREIDA and ORIN, the information included was highly variable and incomplete for nearly all programs. Improving the completeness of information in these databases has the potential to allow students to make more informed application decisions.