Comparative outcomes of Bernese periacetabular osteotomy in adolescents, young adults, and middle-aged adults

Aims: Bernese periacetabular osteotomy (PAO) is a well-established procedure for symptomatic hip dysplasia in adolescents and young adults. Its application in middle-aged patients remains debated due to concerns regarding complications and uncertain outcomes. This study evaluated the safety and effectiveness of PAO in middle-aged patients by comparing minimum two-year outcomes with those of younger cohorts. Methods: We conducted a retrospective cohort study of patients who underwent PAO between June 2015 and December 2021 with a minimum two-year follow-up. Patients with previous hip surgery or systemic conditions affecting outcomes were excluded. The final cohort comprised 27 hips in 16 adolescents (Group A, 11 to 19 years), 24 hips in 18 young adults (Group B, 20 to 39 years), and 17 hips in 14 middle-aged adults (Group C, 40 to 57 years). Radiological parameters, complications, and patient-reported outcomes (PROs), including visual analogue scale (VAS) pain scores, and modified Harris Hip Score (mHHS), were compared among groups. Results: All age groups demonstrated significant improvements in radiological parameters and PROs. Median mHHS improved from 84.7 (IQR 84.7 to 84.7) to 95.7 (IQR 95.7 to 100) in Group A, 81.4 (IQR 75.9 to 84.7) to 95.7 (95.7 to 100) in Group B, and 73.7 (66.0 to 75.9) to 95.7 (90.2 to 100) in Group C. No significant between-group differences in radiological parameters or PROs were observed at final follow-up. Complication rates were comparable across groups except for osteotomy site healing. The middle-aged group demonstrated longer osteotomy union times than the adolescent and young adult groups (median 13 months (IQR 10 to 14) vs six months (IQR 6 to 11) vs six months (IQR 5 to 7); (p < 0.001). Delayed union did not adversely affect functional outcomes or rehabilitation. Conclusion: Carefully selected middle-aged patients with hip dysplasia demonstrated favourable radiological and functional outcomes after PAO despite longer osteotomy union times, with complication rates comparable with younger cohorts. These findings support the safety and effectiveness of PAO in selected middle-aged patients with dysplasia-associated Tönnis grade I to II osteoarthritis.