Complications in simultaneous bilateral total knee arthroplasty, is it a safe procedure?

Background: There is controversy regarding various aspects of simultaneous bilateral total knee replacement (SBTKR). We found disparity in the postoperative outcomes and complications associated with the procedure in the literature linked with the topic. Objective: To retrospectively analyze the need for blood transfusion after surgery and complications associated with total knee replacement according to the type of procedure (SBTKR or unilateral). Methods: Retrospective cohort analytical study. We included 251 patients with severe knee osteoarthritis that were divided into two groups. 124 (49%) who underwent SBTKR and 127 upon whom unilateral total knee replacement (UTKR) was performed. Demographic data, days of hospitalization, complications within the first 90 days after surgery (thromboembolic events, superficial and deep infection, stiffness, death); and percentages of patients transfused with blood products during hospitalization were evaluated. Results: There were no statistical differences in the analysis of postoperative complications in the first 90 days after surgery. In the SBTKR group, 8 patients (6.5%) presented some thromboembolic complication during the postoperative period, while this event was observed in only 2 patients (1.5%) from the other group. The analysis showed a statistically significant drop in postoperative hemoglobin, on average that of 0.8 g/dl, in the SBTKR patient group compared to the UTKR group (95% CI 0.44-1.13; p < 0.001). A higher proportion of patients who required transfusion were observed in the SBTKR group (40%) (OR = 7.12; 95% CI 3.3-16; p < 0.001). We analyzed the cause of postoperative transfusion in the patients who required transfusion taking into account two parameters: hemoglobin less than 8 g/dl and the clinical needs of the patients (symptoms of hypotension, decay, difficulty to rehabilitate without pain, dyspnea). 59 patients received transfusion (50 in the SBTKR group and 9 in the other group). Of these, 19 patients (32.2%) did not meet any transfusion criteria. Conclusion: We consider SBTKR a safe procedure, which does not increase postoperative complications compared to UTKR. Although there is an increase in blood loss in SBTKR, it does not generate clinical symptoms of relevance.