Simultaneous versus staged bilateral total knee arthroplasty: a meta-analysis evaluating mortality, peri-operative complications and infection rates.

Background: An important source of debate in many orthopaedic practices is the choice of performing simultaneous or staged bilateral total knee arthroplasty.

Questions/purpose: The objective of this meta-analysis is to compare simultaneous bilateral with staged bilateral total knee arthroplasty for peri-operative complication rates, infection rates and mortality outcomes.

Methods: All relevant citations were retrieved from MEDLINE, EMBASE, COCHRANE databases and the unpublished literature. Included studies were assessed for methodological quality and abstracted data was conducted independently by two reviewers. Data was categorized into subgroups and pooled using the DerSimonian and Laird's random effects model.

Results: A total of 18 articles were identified from 873 potentially relevant titles and selected for inclusion in the primary meta-analyses. The incidence of mortality was significantly higher in the simultaneous group at 30 days (RR [relative risk] 3.67, 95% confidence interval [CI] 1.68-8.02, p = 0.001, I (2) = 59%, n = 67,691 patients), 3 months (RR 2.45, 95% CI 2.15-2.79, p < 0.00001, I (2) = 0%, n = 66,142 patients) and 1 year (RR 1.85, 95% CI 1.66-2.06, p < 0.001, I (2) = 0%, n = 65,322 patients) after surgery. However, there were no significant differences between the two groups in regards to in-hospital mortality rates (R 1.18, 95% CI 0.74-1.88, p = 0.48, I (2) = 0%, n = 33,814 patients). In addition, there was no increased risk of deep vein thrombosis, cardiac complication, and pulmonary embolism or infection rates in either comparison group.

Conclusions: The results of the analysis suggest that simultaneous bilateral total knee arthroplasty has a significantly higher rate of mortality at 30 days, 3 months and 1 year after surgery, but similar infection and complication rates in comparison to staged bilateral total knee arthroplasty.