Factors associated with long-term patient-reported outcomes after periacetabular osteotomy

Long-term survivorship and patient-reported outcomes after periacetabular osteotomy (PAO) have been reported; however, the relationships of long-term PROMs with preoperative cartilage degeneration and postoperative three-dimensional hip morphology remain incompletely understood. This study evaluated long-term PROMs and examined their associations with preoperative cartilage T2 values and postoperative hip morphology after PAO. This retrospective study included 42 hips in 42 patients with early-stage osteoarthritis who underwent PAO for developmental dysplasia of the hip and were followed for more than 10 years. Clinical outcomes were assessed preoperatively and at final follow-up, whereas the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) was assessed at final follow-up. Hip morphology was evaluated using computed tomography (CT), and cartilage degeneration was assessed using preoperative T2 mapping magnetic resonance imaging. Associations with final JHEQ scores were analyzed using correlation analyses and multivariable linear regression with JHEQ scores treated as continuous outcomes. The mean final total JHEQ score was 56.4 ± 19.6 points. In the multivariable linear regression model for total JHEQ (adjusted $${R}^{2}=0.311,P<0.001$$ ), higher preoperative acetabular T2 values ( $$B=-1.915$$ , 95% CI $$-2.913$$ to $$-0.917$$ ; $$P<0.001$$ ) and a larger postoperative combined angle ( $$B=-0.298$$ , 95% CI $$-0.588$$ to $$-0.008$$ ; $$P=0.045$$ ) were independently associated with a lower total score. For the JHEQ pain subscale (adjusted $${R}^{2}=0.301,P<0.001$$ ), higher acetabular T2 values remained independently associated with worse pain ( $$B=-0.748$$ , 95% CI $$-1.199$$ to $$-0.297$$ ; $$P=0.002$$ ), whereas femoral anteversion was not independently significant ( $$B=-0.206$$ , 95% CI $$-0.462$$ to $$0.049$$ ; $$P=0.111$$ ). Greater preoperative acetabular cartilage T2 values and postoperative combined sagittal/coronal coverage were associated with worse long-term patient-reported outcomes after PAO. These findings suggest that quantitative preoperative cartilage assessment and careful postoperative morphological correction may be relevant to long-term outcomes.