Outpatient total knee arthroplasty: is it economically feasible in the hospital setting?

Background: With the removal of total knee arthroplasty (TKA) from the Medicare inpatient-only list, outpatient TKA can now be offered, irrespective of payer, in multiple sites. We compared time- and cost-effectiveness of outpatient TKA performed in a hospital outpatient department (HOPD) to that at an inpatient academic medical center (AMC).

Methods: We reviewed all outpatient TKAs performed at our AMC and our HOPD from August 2018 to July 2019. Time efficiency by phase of care was determined, and cost data were obtained from the hospital financial department. Patient selection for outpatient surgery was identical for each site of care.

Results: We identified 21 knees that had surgery at the HOPD and 65 knees that had surgery at the AMC. Demographics were similar in both groups. The AMC group had significantly longer in-facility to operating room (Δ (difference) = 33.5 minute,  = .0003), postanesthesia care unit to discharge (Δ = 158.8 minute, < .0001) and in-facility to discharge (Δ = 199.3 minute, < .0001) time periods compared to the HOPD group. The HOPD was significantly more cost-effective for the preoperative period (Δ = $75.7, < .0001), postoperative period (Δ = $315.1, < .0001), and total cost (Δ = $241, < .0001).

Conclusions: Outpatient TKAs performed in an HOPD spend significantly less time within the facility than the ones performed in an AMC and cost significantly less. It is expected that approval of Medicare TKAs at ambulatory surgery centers will further improve cost and efficiency.