Incidence and short-term outcomes of primary and revision hip replacement in the United States

Background: The purpose of this study was to use 2003 nationwide United States data to determine the incidences of primary total hip replacement, partial hip replacement, and revision hip replacement and to assess the short-term patient outcomes and factors associated with the outcomes. Methods: We screened more than eight million hospital discharge abstracts from the 2003 Healthcare Cost and Utilization Project Nationwide Inpatient Sample and approximately nine million discharge abstracts from five state inpatient databases. Patients who had undergone total, partial, or revision hip replacement were identified with use of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes. In-hospital mortality, perioperative complications, readmissions, and the association between these outcomes and certain patient and hospital variables were analyzed. Results: Approximately 200,000 total hip replacements, 100,000 partial hip replacements, and 36,000 revision hip replacements were performed in the United States in 2003. Approximately 60% of the patients were sixty-five years of age or older and at least 75% had one or more comorbid diseases. The in-hospital mortality rates associated with these three procedures were 0.33%, 3.04%, and 0.84%, respectively. The perioperative complication rates associated with the three procedures were 0.68%, 1.36%, and 1.08%, respectively, for deep vein thrombosis or pulmonary embolism; 0.28%, 1.88%, and 1.27% for decubitus ulcer; and 0.05%, 0.06%, and 0.25% for postoperative infection. The rates of readmission, for any cause, within thirty days were 4.91%, 12.15%, and 8.48%, respectively, and the rates of readmissions, within thirty days, that resulted in a surgical procedure on the affected hip were 0.79%, 0.91%, and 1.53%. The rates of readmission, for any cause, within ninety days were 8.94%, 21.14%, and 15.72%, and the rates of readmissions, within ninety days, that resulted in a surgical procedure on the affected hip were 2.15%, 1.61%, and 3.99%. Advanced age and comorbid diseases were associated with worse outcomes, while private insurance coverage and planned admissions were associated with better outcomes. No consistent association between outcomes and hospital characteristics, such as hip procedure volume, was identified. Conclusions: Total hip replacement, partial hip replacement, and revision hip replacement are associated with different rates of postoperative complications and readmissions. Advanced age, comorbidities, and nonelective admissions are associated with inferior outcomes. Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.