Research Summary

Outpatient Revision TKA Offers Comparable Outcomes to Inpatient Surgery in Select Patients

Anthony Calabro, MA

Key Highlights

  • Researchers found no difference in 1-year repeat revision rates between inpatient and outpatient revision total knee arthroplasty (TKA).
  • Outpatient revision TKA was associated with lower 90-day hospital readmission rates.
  • There was no increase in medical or surgical complications was observed in outpatient cohort.
  • The authors noted that careful patient selection is essential for outpatient revision TKA viability.

A large retrospective cohort study found that outpatient single-component revision total knee arthroplasty (TKA) is not associated with higher rates of repeat revision, hospital readmission, or perioperative complications compared with the inpatient setting.

With the demand for revision TKA procedures rising, health systems are exploring ways to improve resource utilization without compromising patient outcomes. Given the complex nature of revision procedures and the comorbidity burden in this patient population, concerns about safety and efficacy in outpatient settings persist. This study aimed to clarify whether outpatient revision TKA poses increased risks compared with traditional inpatient surgery.

Using the PearlDiver Mariner database, researchers analyzed records of patients who underwent single-component revision TKA between 2010 and 2022. Patients were categorized by surgical setting—outpatient or inpatient—and matched via propensity scoring (1:4 ratio) based on age, gender, and Elixhauser Comorbidity Index. The final cohort included 7731 patients in the outpatient group and 30,924 in the inpatient group. The primary outcomes evaluated were 1-year repeat revision rates, 90-day hospital readmissions, and rates of medical and surgical complications, including deep vein thrombosis, pulmonary embolism, wound issues, periprosthetic joint infection, and need for manipulation under anesthesia.

The analysis revealed no statistically significant difference in 1-year repeat revision rates between outpatient and inpatient groups (5% vs 5%; P = .05). Additionally, the 90-day hospital readmission rate was lower among outpatient cases (8% vs 15%; P < .001). There were also no statistically significant differences in the incidence of other complications, indicating that outpatient revision TKA was not inferior to inpatient revision across the outcomes assessed.

Despite propensity score matching, the authors described the possibility of selection bias, as patients treated in the outpatient setting may have been healthier in ways not fully captured by comorbidity indices. Furthermore, the use of administrative coding data limits the granularity of clinical detail available for assessing intraoperative complexity or postoperative care pathways. The authors also noted that the results do not suggest that revision TKA in the outpatient setting is appropriate for all patients.

“In this study, outpatient revision TKA did not have a higher incidence of repeat revision, hospital readmission, and medical or surgical complications compared with performing revision TKA in an inpatient setting,” the authors wrote. “However, we do not suggest that revision TKA in the outpatient setting is appropriate for all patients or that it is safer than in the inpatient setting, as there was some unmeasured confounding despite propensity matching in this large data set.”

The authors determined that to refine best practices and improve clinical decision-making, future studies should compare outpatient versus inpatient revision TKA as it relates to patient selection criteria and outcomes such as patient satisfaction, pain scores, and cost savings.

“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,” the authors concluded. “When determining the appropriate setting for revision TKA, it is crucial to consider the patient’s overall health and medical comorbidities.”

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. Published 2025 Feb 5. doi:10.1097/CORR.0000000000003386