The trajectory of patient-reported outcomes after hip preservation surgery: A National Registry Study.

Purpose: Understanding the trajectory of postoperative patient-reported outcomes after hip preservation surgery is essential. This study aims to analyse patient-reported outcome trajectories up to 2 years post-surgery using the UK's national hip preservation registry and to examine the influence of potential confounders.

Methods: Patients who underwent hip arthroscopy or periacetabular osteotomy with preoperative International Hip Outcome Tool-12 (iHOT-12) scores and at least two follow-up measurements at 6 months, 1 year, or 2 years were included from the UK Non-Arthroplasty Hip Registry. iHOT-12 score trajectories were analysed, and Latent Growth Curve Modelling was used to identify predictors of these trajectories.

Results: Overall 9845 patients were included in this study. 7081 patients underwent a hip arthroscopy, and 1327 patients underwent a periacetabular osteotomy. For hip arthroscopy, there were significant improvements in the iHOT-12 scores from baseline to 6 months, but no significant change from 6 months to 1 year. However, there was a decrease in the minimal clinically important difference from 1 to 2 year. For periacetabular osteotomy, there were significant improvements in the iHOT-12 scores from baseline to 6 months, but no significant change from 6 months to 1 year, and from 1 to 2 years. Latent Growth Curve Modelling showed that body mass index (BMI) and sex had a significant impact on pre-operative iHOT-12 scores, while age and sex significantly influenced the recovery slope.

Conclusions: Patients who underwent hip preservation surgery exhibited significant improvement in iHOT-12 scores, surpassing the minimal clinically important difference at 6 months postoperatively. This improvement plateaued by 2 years, with a slight decline in scores between 1 and 2 years following hip arthroscopy, though the decrease remained within the clinically meaningful range. BMI, age and sex influenced score trajectories, highlighting the importance of setting patient expectations pre-operatively.

Trial registration: The UK's Non-Arthroplasty Hip Registry https://www.nahr.co.uk/.

Levels of evidence: Level III.