Same-day bilateral total knee replacement versus unilateral total knee replacement: A comparative study

Introduction: Bilateral total knee arthroplasty (TKA) in a single session is rarely done in France, mainly due to the increased risk of perioperative and late complications. The primary objective of this study was to compare the complication rates of same-day bilateral TKA (TKA bilat) with that of unilateral TKA (TKA unilat). The hypothesis was bilateral TKA increases the rate of early and late complications in a group of selected patients (ASA 1 or 2, less than 80 years of age).Material and methods: Retrospective comparative study of 91 bilat TKA and 182 unilat TKA cases operated on between 2009 and 2016 (1 bilat TKA paired with 2 controls). The patients were matched based on age, sex, indication and ASA score. The minimum follow-up was 2 years. Mortality along with early and late complications were documented. The secondary endpoints were implant survival, functional outcomes, and patient satisfaction.Results: The early mortality rate was zero in both groups. The early complication rate was lower in the bilat TKA group (9%) than in the unilat TKA group (22%) (p < 0.001). The late complications did not differ between groups. Implant survival at 5 years was 99% (95% CI = [95.6-99.7]) in the bilat TKA group and 97% (95% CI = [92.8-98.8]) in the unilat TKA group. The autologous blood transfusion rate was 33% in the bilat TKA group and 2.2% in the unilat TKA group (p < 0.001). There was no difference between groups in the satisfaction rate or the KOOS and New IKS scores. A larger share of patients in the unilat TKA group (54%) said they had forgotten about their knee than in the bilat TKA group (43%) (p = 0.036).Discussion: There were few early complications in the bilat TKA group. There was no significant difference in the number of late complications, survival, functional scores, or patient satisfaction between the two groups. The transfusion rate was higher in the bilat TKA group, while the forgotten knee rate was higher in the unilat TKA group.Conclusion: Our hypothesis was not confirmed: in the context of this study, in patients who are ASA 1 or 2, and less than 80 years old, same-day bilateral TKA does not increase the complication rate relative to unilateral TKA.Level of evidence: III, comparative study of continuous paired cases. (c) 2022 Elsevier Masson SAS. All rights reserved.