Hospital Length of Stay following Primary Total Knee Arthroplasty: Data from the Nationwide Inpatient Sample Database.

Demand and cost of total knee arthroplasty (TKA) has increased significantly over the past decade resulting in decreased hospital length of stay (LOS) to counterbalance increasing cost of health care. The purpose of this study was to determine the factors that influence LOS following primary TKA. Discharge data from the 2009-2011 Nationwide Inpatient Sample were used. Patients included underwent primary TKA and were grouped based on LOS; 3 days or less, and 4 days or more. Majority of patients had a hospital LOS of 3 or less (74.8%). The most significant predictors of increased hospital LOS (≥ 4 days) were age ≥ 80 years, Hispanic race, Medicaid payer status, lower median household income, weekend admission, rural non-teaching hospital, discharge to another facility and any complication.