Discharge disposition does not change between first and second staged bilateral total knee arthroplasty

The demand for total knee arthroplasty (TKA) is increasing, with up to 40 % of primary TKA patients undergoing contralateral TKA within 8 years. While prior studies have focused on perioperative complications and cost-effectiveness in staged bilateral TKA, there is limited research on how a prior TKA affects discharge disposition and patient-reported outcome measures (PROMs). This study aimed to compare discharge disposition and patient satisfaction between first and second TKA procedures. A retrospective matched cohort study was conducted using a database of TKA patients from January 2, 2019, to May 17, 2024. Patient demographics, discharge disposition, length of stay (LOS), and PROs were collected. Differences between first and second TKA were analyzed using multinomial and multivariable regression models. A total of 1377 patients undergoing staged bilateral TKA patients were included. Encounter number was not associated with discharge disposition (Odds Ratio 95 % Confidence Interval (ORCI) = 0.20–7.69). First TKA (ORCI: 2.10–2.89), higher ASA class (ORCI: 1.16–1.59), and the use of general anesthesia (ORCI: 2.67–4.63) were predictors of LOS >24 h. Baseline PROMs were higher and VAS pain scores lower for the second knee (p < 0.001). However, second TKA was associated with smaller magnitude of improvements in KOOS JR, PROMIS Global Health, and VAS pain scores at 3, 6, and 12 months compared to the first TKA. Discharge disposition is similar between the first and second TKA procedures. Surgeons should counsel patients that discharge after the second TKA is likely to mirror the first. Although baseline PROMs are higher for the second knee, the magnitude of improvement is greater following the first TKA. • Discharge disposition is similar between the first and second TKA. • Length of stay was longer in first compared to second TKA. • Baseline PROs were higher prior to second TKA compared to index surgery.