Staged Bilateral Total Knee Arthroplasty: Time of the Second Side.

The purpose of this study was to determine if there was a safe time frame for performing the second total knee arthroplasty (TKA) in staged bilateral TKAs. Retrospectively, 589 TKAs were studied at a single institution from January 2000 to June 2012. Patients were excluded if they underwent simultaneous or staggered bilateral TKA during the same hospitalization. Patients were included if they underwent bilateral staged TKA during a different hospitalization within 21 to 90, 91 to 180, 181 to 270, and 271 to 360 days after the first TKA. In-hospital complications were determined using International Classification of Diseases, Ninth Revision codes for cardiac, pulmonary, urinary, deep vein thrombosis, wound complications, mechanical complications, and wound infections. Periprosthetic joint infection (PJI) was determined by hospital readmission records. There were 29 postoperative complication events (4.9%) and there was no difference between time groups and complications. The highest rates of PJI occurred when the second TKA was performed after 271 to 360 days (3.6%), followed by the early postoperative period after 21 to 90 days (2.7%). We could not identify a time frame for performing the second TKA in staged bilateral TKAs to reduce complications. A signal from the study suggests that complications, particularly PJI, may be lower if the second TKA is performed more than 90 days and less than 270 days after the first TKA, although this finding was not significant.