Total Hip Arthroplasty for End-Stage INFH and OA Arthropathy: A 15-Year Population-Based Study

Background: Patients with end-stage ischemic necrosis of the femoral head (INFH) and osteoarthritis (OA) may require total hip arthroplasty (THA). Understanding their demographic characteristics and their hospital baseline outcomes, including length of stay (LOS) and medical costs, is important to optimizing pre-operative planning. Objectives: Compare the demographic characteristics, LOS and medical costs of INFH and OA patients from Taiwan who underwent THA. This study used Taiwan's National Health Insurance Research Database (NHIRD). Methods: Using the claim data for in-hospital medical resource utilization of one million patients from January 1, 1996 to December 31, 2010, we identified 1,019 INFH and 1,169 OA diagnosis with THA procedure data. We compared these patients in terms of sex, age, Charlson Comorbidity Index (CCI) score, hospital level, hospital location, surgeon's age and hospital medical fees. The variables related to LOS were statistically analyzed by linear regression and multiple linear regression to identify correlations between the two groups. Results: There were statistically significant differences in age, sex, CCI score, hospital level, hospital location, surgeon's age, laboratory fees, and anesthesia fees between the INFH and OA patients. The mean age of the INFH THA patients, who were predominantly male (INFH, 79.6%; OA, 38.8%) was younger (47 years) than that of the OA THA patients (64 years). However, there was no significant difference in the average LOS and total medical expenses between the two groups. Regardless of disease entity, the THA patients' LOS was found to be shorter in female patient, lower CCI score, medical center, order surgeon's age and hospital location of northern area. Conclusions: INFH and OA patients undergoing THA have unique demographic characteristics. The variables related to LOS, include patient's sex, CCI score, hospital level, hospital location, and surgeon's age, will help surgeons to more accurately inform patients during the THA preoperative planning stage.