The role of routine laboratory tests after unilateral total knee arthroplasty

Abstract

BackgroundRecent studies suggest that routine laboratory tests are not required within 1 day after partial knee arthroplasty. This study aimed to evaluate the utility of routine postoperative laboratory tests after initial unilateral total knee arthroplasty(TKA) in an Asian population and to identify risk factors associated with abnormal test results.MethodsThe clinical data of patients who underwent original unilateral TKA from 2015 to 2020 were retrospectively analyzed. Patient characteristics and laboratory test values were recorded. Multivariate binary logistic regression analysis was also performed to identify risk factors associated with 3 abnormal laboratory values.ResultsA total of 713 patients were included in this study and underwent relevant laboratory tests within 3 days of TKA surgery. However, only a small proportion of patients with anemia (8.1 %), hypoalbuminemia (9.9 %), and abnormal serum potassium levels (3.4 %) required clinical intervention after surgery. Binary logistic regression analysis revealed that independent risk factors for postoperative blood transfusion in TKA patients included preoperative hemoglobin level, estimated blood loss, and age. Related risk factors for postoperative albumin supplementation were preoperative albumin level, intraoperative blood loss and operation time. In addition, lower body mass index (BMI) and preoperative hypokalemia were found to be potential risk factors for postoperative potassium supplementation.ConclusionSince more than 90% of abnormal postoperative laboratory tests do not require clinical intervention, the authors believe that it is of little significance for patients with primary unilateral TKA to receive routine laboratory tests after surgery. However, in patients with established risk factors, postoperative laboratory testing is still necessary.