EP2.40 So-called ‘Borderline’ Hip Dysplasia Should Be Treated with Periacetabular Osteotomy
Bibliographic record
Abstract
Abstract Introduction: Periacetabular osteotomy (PAO) has a recognized success for the treatment of hip dysplasia with lateral center-edge angle (LCEA) ≤20°. In cases of mild or so-called ‘borderline’ hip dysplasia with (LCEA>20°;<25°), there is no clear consensus on the definitive treatment, for which either arthroscopy or PAO were proposed. We aimed to report the radiologic and functional outcomes of patients with so-called ‘borderline’ dysplasia treated with PAO. Methods: We retrospectively analyzed 123 cases undergoing PAO between 2016-2023, of which 73 (94.6% females) were classified as ‘mild’ dysplasia, defined as LCEA>20°, anterior wall index (AWI) ≤0.3 and/or posterior wall index (PWI) ≤0.85, and any tomographic anterior (AASA) or posterior acetabular sector angle (PASA) below the corresponding threshold value proposed by Verhaegen et al (superior ASA 116°; proximal-AASA 133°; proximal-PASA 142°; intermediate-AASA 66°; intermediate-PASA 102°; equatorial-AASA 57°; equatorial-PASA 96°). Mean follow-up was 22.1(12.2;31.2) months. Demographic data were recorded, and two observers measured baseline radiographic measurements, with all Bland-Altman plots within 95% agreement. Patients were classified according to a modified-Ottawa classification using both radiographic (AWI,PWI) and tomographic (AASAs/PASAs) wall measurement: anterior-wall-deficient-hips (n=17), posterior-wall-deficient-hips (n=44), and both-walls-deficient-hips (n=15); with the latter including only LCEAs >20°. Outcome measures included delta-angular correction, delta-UCLA score and postoperative complications as per the Dindo-Clavien classification. Results: The 3 groups were significantly different in terms of preoperative radiographic measurements (p>0.05). Mean preoperative LCEA, Tönnis angle, AWI, PWI, of the anterior-wall-deficient-group were 22°[21.3°;24.8°], 10.9±1.7°, 0.28±0.09, and 1.07±0.09, respectively. Mean preoperative values of the posterior-wall-deficient-group were 24.6°[22°;28°], 10.8±2°, 0.48±0.12, and 0.81±0.11, respectively. Mean preoperative values of the both-walls-deficient-group were 22.3°[20.8°;27°], 10±1.2°, 0.38±0.16, and 0.97±0.09, respectively. Significant differences were found after PAO in all groups. Postoperative LCEA, AWI, PWI, of the anterior-wall-deficient-group were 34.4±4.88°(p<0.001), 0.44±0.19(p=0.003) and 0.98±0.16(p=0.024). Postoperative LCEA, AWI, PWI, of the posterior-wall-deficient-group were 35.1±4.92°(p<0.001), 0.55±0.16(p=0.013) and 0.93±0.1(p<0.001). Postoperative LCEA, AWI, PWI, of the both-walls-deficient-group were 32.1±5.67°(p=0.001), 0.54±0.28(p=0.025) and 1.03±0.13(p=0.184). Statistically significant differences were found between preoperative-postoperative UCLA values (7.00[6.00;7.00] vs 9.00 [9.00;9.00];p<0.001). Seven complications were recorded (all grades 1-2), one of which required additional surgical intervention. Conclusion: PAO showed excellent early clinical-radiological outcomes in mild-dysplasia cases, independently of the dysplasia subtype.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".