Eighteen studies (27,807 patients) were included in the review. The total number of knee arthroplasties was 44,684, of which 10,930 were unilateral total knee arthroplasties, 16,419 were simultaneous bilateral total knee arthroplasties, and 458 were staged bilateral total knee arthroplasties. The number of randomised controlled trials was not reported.
The authors stated that effect sizes differed across the studies.
The prevalence of mortality was significantly greater in the population that had undergone simultaneous total knee arthroplasty (OR 2.24, 95% CI: 1.21, 4.16; 8 studies).
The probability of a deep vein thrombosis occurring was lower after simultaneous total knee arthroplasty but not significantly lower (pooled OR 0.99, 95% CI: 0.47, 2.08; 6 studies).
The probability of a pulmonary embolism was higher in patients who had undergone simultaneous total knee arthroplasty than in patients who had undergone a unilateral total knee arthroplasty (overall pooled OR 1.82, 95% CI: 1.01, 3.26; 11 studies).
Almost all articles showed an increase in the prevalence of cardiac events in patients who had undergone simultaneous total knee arthroplasty (overall pooled OR 2.49, 95% CI: 1.31, 4.73; 8 studies).