Periacetabular Osteotomy (PAO) has become the most important surgical procedure for patients with hip dysplasia, offering significant pain relief and improved joint function. This study focuses on recovery after PAO, specifically the return to sports (RTS) timeline, with the objective of identifying preoperative predictors to optimize patient outcomes.

Our prospective, monocentric study from 2019 to 2023 included 698 hips from 606 patients undergoing PAO. Comprehensive preoperative data were collected, including demographic information, clinical assessments (Modified Harris Hip Score (mHHS), International Hip Outcome Tool-12 (iHot-12), Hip Disability and Osteoarthritis Outcome Score (HOOS), UCLA Activity Score) and psychological evaluations (Brief Symptom Inventory (BSI) and SF-36 Health Survey). Advanced logistic regression and machine learning techniques (R Core Team. (2016)) were employed to develop a predictive model.

Multivariate regression analysis revealed that several preoperative factors significantly influenced the RTS timeline. These included gender, invasiveness of the surgical approach, preoperative UCLA Score, preoperative sports activity level, mHHS, and various HOOS subscales (Sport/Recreation, Symptoms, Pain) as well as psychological factors (BSI and SF-36). The subsequent model, using a decision tree approach, showed that the combination of a UCLA score greater than 3 (p<0.001), non-female gender (p=0.003), preoperative sports frequency not less than twice per week (p<0.001), participation in high-impact sports preoperatively (p=0.008), and a BSI anxiety score less than 2 (p<0.001) had the highest likelihood of early RTS with a probability of 71.4% at three months.

Using a decision tree approach, this model provides a nuanced prediction of RTS after PAO, highlighting the synergy of physical, psychological, and lifestyle influences. By quantifying the impact of these variables, it provides clinicians with a valuable tool for predicting individual patient recovery trajectories, aiding in tailored rehabilitation planning and predicting postoperative satisfaction.

The use of trabecular metal (TM.) shells supported by two TM augments in the footing technique has been described as a potential option for the treatment of Paprosky 3B acetabular defects. The aim of this study was to assess the mid implant survivorship and radiological and clinical outcomes after acetabular revision using this technique.

We undertook a retrospective, double-centre series of 39 hips in 39 patients (15 male, 24 female) treated with the footing technique using a TM shell supported by two TM augments, for severe acetabular bone loss between 2007 and 2020. The mean age at the time of surgery was 62,9 (28 to 86) years. The mean follow-up was 5,4 (1,5 to 15) years.

The cumulative mid survivorship of the implant with revision for any cause was 89%. 3 hips (7,6%) required further revision due to aseptic loosening, and 1 (2,8%) required revision for infection. The mean Harris Hip Score improved significantly from 48 (29 to 65) preoperatively to 79 points (62 to 98) at the latest follow-up (p < 0.001).

The reconstruction of Paprosky 3B acetabular defects with TM shells and two augments in footing-technique showed excellent mid-term results. This technique appears to be a viable option for treating these defects.