Frailty Among Revision Total Knee Arthroplasty Recipients: Epidemiology and Propensity Score-weighted Analysis of Effect on In-hospital Postoperative Outcomes.

BACKGROUND: Frailty has been shown to correlate with worse outcomes after total knee arthroplasty (TKA), although less is known regarding its effect on revision TKA (rTKA). This study examines the epidemiologic characteristics and inpatient outcomes of patients with frailty undergoing rTKA.

METHODS: Discharge data from National Inpatient Sample registry were used to identify all patients aged 50 years or older who underwent rTKA between 2006 and 2015. Patients were stratified into frail and nonfrail groupings, based on the presence of specific International Classification of Diseases-9 diagnostic coding. An analysis comparing the epidemiology, medical comorbidities, and propensity score-weighted postoperative clinical and economic outcomes of the two groups was done.

RESULTS: From 2006 to the third quarter of 2015, a total of 576,920 patients (17,727 frail) who underwent rTKA were included. The average age in the study's population was 67.2 years, with a female distribution of 57.4%. Frail patients were more likely to exhibit markedly higher rates of almost all modified Elixhauser Comorbities than their nonfrail counterparts. Frail patients were also more likely to undergo different types of revisions, including an increased rate of removal of the prosthesis without replacement. In addition, frail patients displayed increased likelihood of experiencing any postoperative complication, deep vein thrombosis, postoperative anemia, respiratory complications, and wound dehiscence. Frail patients experienced lower rates of discharge home and increased length of stay than the nonfrail cohort.

DISCUSSION: Patients with frailty undergoing rTKA are at markedly higher risk for inpatient postoperative complications and increased length of stay. Understanding the implications of frailty within rTKA is essential for risk assessment and preoperative optimization for this expanding population.