Costs and Risk Factors for Hospital Readmission After Periprosthetic Knee Fractures in the United States.

BACKGROUND: Periprosthetic fractures (PPFX) around total knee arthroplasty (TKA) are devastating complications with significant morbidity. With growing healthcare costs, hospital readmissions have become a marker for quality healthcare delivery. However, little is known about the risk factors or costs associated with readmission after treatment of PPFX. We sought to identify the patient demographics, prevalence of treatment types (open reduction internal fixation [ORIF] vs revision TKA), 30 and 90-day readmission rates, costs of initial treatment and readmission, and risk factors for readmission.

METHODS: We used the 2013 Nationwide Readmissions Database to select patients who underwent TKA, revision TKA, and treatment of PPFX with either ORIF or revision TKA. The 90-day readmission rate was determined through a survival analysis, and risk factors were identified using a cox proportional hazards model that adjusted for patient and hospital characteristics.

RESULTS: We identified 1526 patients with PPFX treated with ORIF and 1458 treated with revision TKA. Ninety-day readmissions were 20.5% and 21.8%, respectively. Patients with ORIF were more often female and had multiple medical comorbidities. Patient factors associated with readmission included advanced age, male gender, comorbidities, discharge to a skilled nursing facility or home with health aide, and Medicare or Medicaid insurance. Treatment at a teaching hospital was the only hospital-associated risk factor identified. ORIF cost USD 25,539 and revision THA cost USD 37,680, with associated readmissions costing 15,269 and 16,806, respectively.

CONCLUSION: PPFX results in greater costs compared to primary and revision TKA. This study highlights risk factors for readmission after PPFX treatment.