EP8.41 Temporal analysis of patient demographic factors and functional outcomes from periacetabular osteotomy and hip arthroscopy using data from the UK Non-Arthroplasty Hip Registry (NAHR)

Abstract Purpose This study assessed trends in patient demographics and patient-reported outcome measures (PROMs) for patients undergoing peri-acetabular osteotomy (PAO) and hip arthroscopy (HA) for femoroacetabular impingement (FAI) using data from the UK Non-Arthroplasty Hip Registry (NAHR). Methods Relevant HAs for FAI and PAOs with baseline and at least one follow up PROM recorded in the NAHR in 2013-14 (Group 1), 2016-17 (Group 2), 2020-21 (Group 3) and 2024-25 (Group 4) were identified and grouped. PROMS utilised were iHOT-12, EQ-5D Index and EQ-5D Visual Analogue Scale (VAS). Revision procedures were excluded. Descriptive statistics were performed and linear mixed-effects models (LMEM) and ANCOVA models were created for adjusted analysis. Results In the PAO group, median BMI significantly increased after Group 1 (22.9 vs 24.5-24.9). Non-significant trends towards poorer 6 month iHOT-12 score (21 vs 29-29.5) and 6 month iHOT-12 score change from baseline (51 vs 60-68) were observed in Group 3 as well as non-significant trends towards greater 6-month EQ-5D VAS score change in Group 4 ( 7 vs 0-2). LMEM demonstrated non-significant trends towards group differences for iHOT-12 score and group-by-timepoint interaction for EQ-5D VAS scores (p=0.0787). ANCOVA analysis demonstrated no significant trends. In the FAI group, a significant decrease in female sex proportion (58.8% Group 1 to 48.9% in Group 4, p=0.023) and increase in proportion of patients with acetabular cartilage damage (Group 1 = 80.0%, Group 4 = 91.7%, p<0.0001) was noted. Across Groups 1-4 significant improvements in median baseline iHOT-12 score (29vs35, p=0.0001) and decrease in median 6-month iHOT-12 score improvement (27vs18.5, p=0.0042) were noted. Significant decreases from Groups 1-4 in median 6 (79vs75, p=0.0142) and 12-month (80vs70, p=0.0329) EQ-5D VAS were also noted. LMEM demonstrated significant effects of group (p=0.0032) and group-by-timepoint (p=0.0006) on EQ-5D VAS scores as well as a non-significant trend towards effect of group on iHOT-12 scores (p=0.0756). ANCOVA analysis demonstrated no significant trends. Conclusion No consistent trend in PROM scores was identified in patients undergoing PAO in the UK from 2013-2025. LMEM for HA patients demonstrated significantly poorer EQ-5D VAS scores over time and a non-significant trend towards improved iHOT-12 scores from 2013-2025.