Comparison of safety and efficiency between sequential simultaneous bilateral and staged bilateral total knee arthroplasty at a high-volume center: a retrospective cohort study

The treatment strategy remains controversial for bilateral end-stage osteoarthritis, particularly with regard to patient safety. The aim of this study was to compare the safety and clinical results of sequential simultaneous bilateral total knee arthroplasty (ssBTKA) and staged bilateral total knee arthroplasty (staBTKA). Patients who underwent either simultaneous (n=168) or staged (n=63) bilateral total knee arthroplasty in a single center between February 2017 and April 2021 were identified retrospectively. Data related to age, gender, body mass index, ASA score, comorbidities, operative time, transfusion rate, length of stay, knee range of motion (ROM), Knee Society Score (KSS), complications, and mortality rates were evaluated. Mean follow-up duration was 39.0 +/- 14.7 months. Preoperative characteristics were similar among cohorts. Transfused units were significantly higher in the ssBTKA group (p<0.001). Operative time and length of stay were significantly higher in the staBTKA group (respectively, p<0.001 and p=0.004). Complication rates (except superficial infection rate which was significantly higher in the staBTKA group), revision rates, mortality rates and functional outcomes were statistically similar between the groups (p>0.05). Presence of preoperative coronary artery disease comorbidity was significantly associated with increased postoperative myocardial infarction risk (p=0.001). ssBTKA provided similar functional results, shorter cumulative hospital stay and shorter operative time without increasing complications and mortality rates compared to staBTKA procedure. For patients with pre-existing coronary artery disease, a more cautious approach should be preferred to decrease complications.