Summary

Outpatient TKA resulted in superior outcomes which will lead to improved quality of care and lower healthcare costs.

Abstract

Background

Much recent controversy has surrounded the viability of outpatient revision total knee arthroplasty(TKA). The purpose of this study was to compare the surgical outcomes and complications of outpatient revision TKA to those of inpatient revision TKA using a large national database.

Methods

We queried the PearlDiver Mariner database for patients who underwent revision TKA in the outpatient and inpatient settings. These populations were propensity score matched in a 1 to 4 ratio by age, gender, and Elixhauser Comorbidity Index (ECI). Outcome measures included rates of hospital readmission, re-revision, and several medical and surgical complications at time points up to 1 year postoperatively. Queries were based on a combination of Current Procedural Terminology (CPT) and International Classification of Disease (ICD) codes.

Results

116,252 patients were identified who underwent revision TKA in the inpatient setting and 13,861 who underwent outpatient revision TKA. After matching, there were 55,444 inpatients and 13,861 outpatients. Fewer patients in the outpatient group underwent re-revision at 90 days(3.1% vs 3.6%, OR:0.84, P = 0.0016), 6 months(5.2% vs 5.9%, OR:0.87, P = 0.0012), and 1 year(7.8% vs 8.7%, OR:0.89, P = 0.0008). The outpatient group had fewer readmissions at 30 days(5.3% vs 10.8%, OR:0.46, P < 0.0001) and 90 days(7.8% vs 12.9%, OR:0.57, P < 0.0001). The 90-day incidence of blood transfusions(1.2% vs 3.6%, OR:0.32, P < 0.0001), pulmonary embolism(0.22% vs 0.80%, OR:0.25, P < 0.0001), PJI(10.8% vs 17.1%, OR:0.59, P < 0.0001), and DVT(0.58% vs 0.80%, OR:0.72, P = 0.0069) was lower for outpatient revision TKA, as was the 6-month incidence of MUA(2.3% vs 2.7%, OR:0.83, P = 0.0040).

Conclusion

Our large database study showed that revision TKA performed as an outpatient has lower prevalence of complications (DVT, PE, blood transfusion, PJI at 90 days), readmissions(at 30 and 90 days), manipulation under anesthesia (at 6 months )and re-revision(at 3 months, 9 months and 1 year) rates compared to the inpatient setting. Outpatient TKA resulted in superior outcomes which will lead to improved quality of care and lower healthcare costs.