Background
Allogeneic transfusions are commonly used for substantial blood loss in total knee arthroplasty (TKA), but have been associated with adverse effects and increased costs. The purpose of this study is to provide a detailed description of (1) trends of allogeneic blood transfusion; (2) risk factors and adverse events; and (3) discharge disposition, length-of-stay (LOS), and cost/charge analysis for primary TKA patients who received an allogeneic blood transfusion from 2009-2013.