This systematic review synthesized perioperative and functional outcomes following simultaneous bilateral total knee arthroplasty (SBTKA) in obese patients. Following PRISMA guidelines, literature searches of Medline, PubMed, Embase, Scopus, and Cochrane Library were conducted from inception to November 2024. Study selection, data extraction, and ROBINS-I risk-of-bias assessment were performed in duplicate. Perioperative data, complications, and functional outcomes were included. Continuous variables were summarized as means and standard deviations; dichotomous outcomes were reported as pooled proportions. Eleven studies comprising 61,636 obese patients were included. Mean age was 61.6 years, and mean body mass index (BMI) 36.7 kg/m 2 . Mean operative time was 105.8 minutes, blood loss was 739 mL, transfusion incidence was 21.7%, and hospital stay was 3.8 days. Pooled surgical complication rates were 0.95% overall (4.99% excluding the large Remily et al. cohort), and medical complication rates were 7.16% (7.82% excluding Remily et al.). Common complications included deep vein thrombosis (1.1-4.8%), pulmonary embolism (0.6-2.6%), and superficial wound issues (0.5-7.4%). Higher BMI was associated with increased operative time and complications, with rates up to 18.8% in morbidly obese institutional cohorts. Functional outcomes improved postoperatively, with mean Knee Society Score (KSS) rising from 51.6 to 81.5 and KSS function from 45.7 to 77.6. Obese patients undergoing SBTKA experience improved functional gains, and perioperative risks may be similar to those reported for unilateral TKA in obese patients, although this comparison is indirect and should be interpreted with caution. Morbid obesity was associated with higher complication rates and requires cautious patient selection. Comparative studies with staged BTKA in obese patients are needed to elucidate the optimal surgical strategy. III CRD42024622089
Patel et al. (2026) studied this question.