Same-Day Bilateral Total Knee Arthroplasty: Incidence and Perioperative Outcome Trends from 2009 to 2016

Same-day bilateral total knee arthroplasty (BiTKA) is a controversial topic in orthopedics, prompting a consensus statement to be released by national experts. To date, no studies have evaluated the trends of this method since these recommendations. This study utilized a national database to evaluate: 1) incidence; 2) patient characteristics; 3) hospital characteristics; and 4) inpatient course for same-day BiTKAs in the United States from 2009 to 2016.

The National Inpatient Sample database was queried for individuals undergoing same-day BiTKAs, yielding 245,138 patients. Patient demographics included age, sex, race, obesity status and Charlson Comorbidity Index (CCI) score. Hospital characteristics consisted of location/teaching status, geographic region, charges, and costs. Inpatient course included length of stay, discharge disposition, and complications.

Same-day BiTKA incidence decreased from 5.6% to 4.0% over the study ( p < 0.001). Decreases in patient age and female proportion ( p < 0.001 for both) were seen, while African American and Hispanic patients increased ( p < 0.001), as did obese patient proportions ( p < 0.001). Patients with CCI scores of 2 increased, while those with ≥3 decreased ( p < 0.001). Hospital charges increased, while costs decreased ( p < 0.001 for both). Length of stay following same-day BiTKA decreased ( p < 0.001) and routine home discharges increased ( p < 0.001). Most inpatient complications decreased, although the percentage of mechanical complications and respiratory failures increased ( p < 0.01 for all).

During the study period, younger patients with fewer comorbidities underwent BiTKAs, which likely resulted from improved patient assessment and management. Future investigations should include an evaluation of long-term complications and outcomes in certain patient populations for this procedure.