Identifying an Ideal Time Frame for Staged Bilateral Total Knee Arthroplasty to Maximize Functional Outcome.

Compared with staged bilateral total knee arthroplasty (TKA), simultaneous bilateral TKA carries a higher risk of cardiac complications, pulmonary complications, and mortality, especially in patients with preexisting cardiopulmonary disease or advanced age. However, the period of time between staged TKAs that would eliminate these increased risks has yet to be determined. The purpose of this study is to evaluate complication rates and functional outcome in patients who underwent staged bilateral TKA and to determine an optimal time frame for the second knee. The authors retrospectively reviewed 306 patients who underwent staged bilateral TKA between 2002 and 2013. Patients were grouped into 31 to 90, 91 to 180, 181 to 270, and 271 to 365 days interval, where complication and 90-day readmission rates for the second TKA were identified. Patients were also assessed preoperatively and 2 years postoperatively using the Oxford knee score (OKS) and Short-Form (SF)-36. There was no significant difference in complication and 90-day readmission rates between the various groups. The functional outcome of the knees scored 2 years postoperatively using OKS and SF-36 showed comparable results across all four groups. Thus, the authors could not identify an ideal time frame for performing the second TKA with the objective of maximizing functional outcome.