Abstract
BACKGROUND: There is limited evidence on revision rates and functional outcomes for total hip arthroplasty (THA) in Legg-Calve-Perthes disease (LCPD) compared with primary osteoarthritis (OA). The purpose of this study was to compare revision rates, revision indication, and patient-reported outcomes following THA in patients with LCPD versus those with primary OA. METHODS: We conducted a retrospective cohort study using data from the Australian Orthopaedic Association National Joint Replacement Registry. Patients who underwent primary THA for LCPD or primary OA between 2003 and 2023 were included. Revision procedures were identified and rates compared with cumulative percent revision (CPR) with 95% confidence intervals using Cox proportional hazards models adjusted for age and sex assigned at birth. Specific revision indications were examined using indication-specific CPR analyses. Patient-reported outcomes (PROMs) at 6 months-including Oxford Hip Score (OHS), EuroQol Visual Analogue Scale, and overall satisfaction scores-were analyzed using linear and logistic regression models. RESULTS: There were 1,159 THAs for LCPD (median age 45 years, 71.2% male) and 521,603 for primary OA (median age 68 years, 46.3% male), with median follow-up duration of 6.2 years (interquartile range 2.9-10.4) available for analysis. Patients with LCPD incurred a higher CPR in the first 2 weeks postoperatively (adjusted hazard ratio = 2.15, 95% confidence interval [CI] 1.02-4.51, p = 0.044), but no difference was observed beyond this time. The CPR for THA in patients with LCPD at final follow-up of 18 years was 8.5% (95% CI 5.6-12.8) compared with 7.1% (95% CI 7.0-7.3) for patients with primary OA. There was no difference in specific revision cause between the 2 groups. Postoperative PROMs were similar between groups. Patients with LCPD had lower improvement in OHS compared with those with primary OA (adjusted OHS change = -2.0, 95% CI -3.6 to -0.4, p = 0.015). CONCLUSION: In this large national registry study, we demonstrate similar long-term revision rates, indications, and PROMs among patients following THA for LCPD or primary OA. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.