Policymakers have expanded readmissions penalty programs to include elective arthroplasties, but little is known about the risk factors for readmissions following these procedures. We hypothesized that infections after total hip arthroplasty (THA) and total knee arthroplasty (TKA) lead to excess readmissions and increased costs. This study aims to evaluate the proportion of readmissions due to infections following THA and TKA.
Healthcare Cost and Utilization Project–State Inpatient Databases were used for the study. Procedure codes “8151” and “8154” were used to identify inpatient discharges with THA and TKA in Florida (FL) 2009 to 2013, Massachusetts (MA) 2010 to 2012, and California (CA) 2009 to 2011. Readmission was measured by a Centers for Medicare and Medicaid Services (CMS) validated algorithm. Infections were identified by ICD-9-CM codes: 99859, 99666, 6826, 0389, 486, 4821, 00845, 5990, 48242, 04111, 04112, 04119, 0417, 99591, and 99592. Descriptive analysis was performed.
In CA, 4.29% of patients were readmitted with 33.02% of the total readmissions for infection. In FL, 4.7% of patients were readmitted with 33.39% of the readmissions for infection. In MA, 3.92% of patients were readmitted with 35.2% of readmissions for infection. Of the total number of readmissions due to infection, methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA) together accounted for 14.88% in CA, 13.38% in FL, and 13.11% in MA.
The rate of infection is similar across all 3 states and is a leading cause for readmission following THA and TKA. Programs to reduce the likelihood of MRSA or MSSA infection would reduce readmissions due to infection.