Complications associated with staged versus simultaneous bilateral total knee arthroplasty: An analysis of 7747 patients.

Background: Benefits of simultaneous bilateral total knee replacement (TKR) include lower costs, decreased hospital stay, and shorter rehabilitation. This study evaluated complications associated with simultaneous versus staged bilateral TKR within 12 months. We hypothesized that after controlling for comorbidities, the simultaneous group would have the highest rate of complications.

Methods: This retrospective study analyzed the Humana subset of the PearlDiver Patient Records Database. CPT 27447 and associated modifiers were used to identify patients who underwent simultaneous or staged bilateral primary TKRs. Staged bilateral TKRs were performed within 12 months and were stratified by the time between procedures. Primary outcomes were the Centers for Medicare & Medicaid Services' publicly reported complications. Risks of complications were compared using multivariate logistic regression controlling for age, gender, and comorbidities.

Results: Seven thousand seven hundred forty-seven patients underwent simultaneous or staged bilateral TKRs between January 2007 and April 2015. There were lower odds of transfusion and all-cause 90-day readmission but higher odds of mechanical complications and infection for all staged groups compared to the simultaneous. Patients whose staged surgeries were ≪3 months apart had significantly higher odds of undergoing manipulation under anesthesia (MUA).

Conclusions: Higher rates of blood transfusion and readmission were associated with simultaneous bilateral TKR, while higher rates of mechanical complications and infection were associated with staged bilateral TKR. MUA risk was highest in patients staged ≪3 months apart. While there are inherent risks to simultaneous bilateral TKR, surgeons and patients should also be aware of risks associated with staging the procedures.

Level Of Evidence: III.