risk factors for blood loss following total knee arthroplasty

background: blood loss following total knee arthroplasty (tka) is a challenging issue faced by orthopedic surgeons. determination of risk factors for significant blood loss is a significant step toward blood management.objectives: the aim of this study was to determine factors predicting intraoperative blood loss, postoperative drainage, and need to blood transfusion in patients undergoing tka.patients and methods: in a prospective study, 96 consecutive patients who underwent primary cemented tka were included. intraoperative blood loss, postoperative blood drainage, and hemoglobin (hb) drop were measured and analyzed in terms of age, sex, body mass index, and tourniquet closure time.results: the mean age of patients was 68.4 ± 5.6 years (range, 52-75). mean intraoperative blood loss and postoperative drainage were 147.1 ± 97.4 ml and 494.4 ± 188.1 ml, respectively. based on a regression model, males and obese patients had significantly higher intraoperative blood loss (p < 0.05). additionally, male sex and older age were significantly associated with more severe drop in hb on the first postoperative day; however, there was no predictor of need for transfusion in regression analysis.conclusions: male sex and obesity were the risk factor for intraoperative blood loss while the elderly and male patients experienced more severe postoperative bleeding.