Research Summary

Outpatient Revision Total Knee Arthroplasty Shows Comparable Safety to Inpatient Procedures

Miranda Manier, BA

Key Highlights

  • Outpatient revision total knee arthroplasty (TKA) was not associated with higher rates of repeat revision, hospital readmission, or medical/surgical complications compared with inpatient revision TKA.
  • One-year repeat revision rates were equivalent between groups (5%).
  • Ninety-day hospital readmissions and complications were no higher in outpatients, suggesting outpatient surgery can be safe with appropriate patient selection.

In a large database study of more than 38,000 patients, revision total knee arthroplasty (TKA) performed in an outpatient setting was found to be as safe as inpatient procedures. Rates of repeat revision at 1 year, 90-day hospital readmissions, and medical or surgical complications were no higher in outpatients compared with inpatients, supporting the feasibility of outpatient revision TKA in appropriately selected patients.

The demand for revision TKA is escalating, placing greater strain on healthcare systems. Traditionally, revision TKA has been performed in inpatient settings due to concerns over surgical complexity, medical comorbidities, and postoperative complications. However, given advances in perioperative care and the pressure to optimize resource allocation, the potential for outpatient revision TKA requires rigorous evaluation. This study sought to determine whether outpatient revision TKA carries greater risk than inpatient procedures in terms of revision rates, hospital readmissions, and medical or surgical complications.

Using the PearlDiver Mariner database, which includes more than 165 million patient records from 2010 to 2022, investigators identified patients who underwent single-component revision TKA. Patients were classified as inpatient or outpatient based on procedural coding. To minimize selection bias, propensity score matching was performed at a 1:4 ratio for age, sex, and Elixhauser Comorbidity Index. The matched cohort included 30,924 inpatient and 7731 outpatient cases. Outcomes assessed included repeat revision at 1 year, hospital readmission at 90 days, and complications such as deep vein thrombosis, pulmonary embolism, blood transfusion, wound complications, periprosthetic joint infection, and manipulation under anesthesia.

The incidence of repeat revision at 1 year was equivalent between the outpatient and inpatient groups (5% vs 5%; P = .05). Readmissions at 90 days occurred in 8% of outpatients compared with 15% of inpatients (P < .001). The incidence of all medical and surgical complications was no higher in the outpatient cohort than in the inpatient cohort. Because differences favoring outpatient procedures were unlikely to have biological plausibility, the authors interpreted the findings as a demonstration of noninferiority.

As Plancher and colleagues concluded, “. Our findings suggest that with careful patient selection, complication and revision rates can be comparable to those seen with inpatient revision surgery while also freeing up inpatient resources for patients who would benefit from them.”

Reference
Plancher KD, Mannina C, Schwartz E, Briggs KK, Petterson SC. Outpatient revision TKA does not increase incidence of repeat revision or medical and surgical complications compared with inpatient revision TKA. Clin Orthop Relat Res. 2025;483(7):1302-1307. doi:10.1097/CORR.0000000000003386