Trends and Risk Factors in Revision and Re-Revision Total Hip Arthroplasty in Medicare Patients from 2016 to 2022.

Abstract

With the increasing prevalence of total hip arthroplasty (THA), the burden of revision and re-revision surgeries is anticipated to rise. Revision THA (rTHA) presents challenges due to higher mortality risks and its substantial economic burden on the US healthcare system. This study aimed to assess the incidence, diagnoses, and risk factors for both revision and re-revision THA, considering patient- and surgeon-related variables. This retrospective study analyzed 732,544 THAs in the Centers for Medicare & Medicaid Services (CMS) fee-for-service inpatient and outpatient claims data performed between 2016 and 2022. Patient demographics, surgical indications, lengths of stay, discharge statuses, comorbidities, surgeon annual volumes, and years of surgery were collected. The analysis was limited to patients who had two or more years of follow-up after the primary THA. Kaplan-Meier analysis and Cox proportional hazard models were employed to estimate revision rates, identify risk factors for failure, and assess first revisions for re-revisions. The Prentice, Williams, and Peterson Gap Time Model was applied to account for multiple events and varying baseline hazards across re-revisions. The overall revision rate was 3.2%, with a one-year revision rate of 2.1%. Age ≤ 65, women, White race, preoperative diagnosis of fracture or osteonecrosis, prolonged length of stay, discharge to post-acute care facilities, and lower surgeon volume were identified as significant risk factors for revision surgery (P < 0.001). Medical comorbidities most strongly associated with rTHA included malnutrition, dementia, and morbid obesity (P < 0.001). Of the patients undergoing rTHA, 16.5% of patients underwent re-revision. Infection was the diagnosis with the strongest association with re-revision (P < 0.001). This study provides insights into rTHA trends and risk factors in the U.S. Medicare population. Understanding these factors aids in preoperative counseling and enhances planning for improved patient outcomes.