The Borderline Dysplastic Hip: Arthroscopy or PAO?
Bibliographic record
Abstract
Objectives: The borderline dysplastic hip (characterized by a lateral centre-edge angle (LCEA): 20 - 25° and an acetabular index (AI): 10 - 15°) can pose a significant challenge as symptoms may be due to insufficient acetabular coverage, the presence of femoro-acetabular impingement (FAI) or both. Accordingly, different treatment options have been described, including peri-acetabular osteotomy (PAO), hip arthroscopy, open arthrotomy or a combination of procedures. This study aims to determine patient and deformity-specific characteristics that direct treatment decision-making in the borderline dysplastic hip. Furthermore, we describe the early-term results of both the PAO and hip arthroscopy in treating this challenging patient population. Methods: A prospective, multicenter, longitudinal surgical cohort of young adult hips was searched. From 2060 hips, 291 hips satisfied the inclusion criteria of idiopathic borderline dysplasia, adequate follow-up (> 1-year) and functional outcome. Demographic and radiographic features are included in Table 1. Fifty-five hips (19%) had a previous hip operation (most commonly a hip arthroscopy). A number of different procedure types were performed which were broadly divided into 3 groups; PAO-only (n=42), hip arthroscopy-only (n=127) or PAO and intra-articular treatment (either arthroscopically or open, addressing the cam morphology and/or labral pathology) (n=122). Outcome measures included complications-, re-operations- rates and clinical outcomes using the Harris Hip (HHS) and HOOS scores; pre-operatively and at follow-up; the difference was defined as Δ. Patient characteristics, radiographic morphology and clinical outcome measures were compared between the 3 groups. Results: Patients that underwent a PAO were younger and more likely to be female. The PAO groups had a greater number of previous hip procedures (26%, 24%), most of which were hip arthroscopies. The patients that underwent hip arthroscopy had greater incidence of high alpha angles (66%) compared to the PAO groups (35%, 38%) (p<0.001). The PAO groups having slightly more dysplastic features (LCEA, AI, ACEA) (Table 1). At a mean follow-up of 2.5 years, there were no differences in the complication (7-10%, p=0.8) or re-operation rates (13%). Pre-operatively, the PAO groups had inferior HOOS and WOMAC scores compared to the arthroscopy group (p=0.02-7). No differences in the post-op scores were seen (Table 1). The groups that addressed the intra-articular pathology (arthroscopy and PAO-articular treatment) had significantly greater ΔHHS (23) compared to PAO-only (13) (p=0.02). Conclusion: Younger patients, those with a failed previous arthroscopy, without evidence of intra-articular wear and with worse pre-operative function were more likely to receive a PAO (with or without articular adjunct treatment). Addressing the intra-articular and impingement-related pathology (in addition to a when a PAO is considered necessary) was associated with better improvement in PROMs and should be strongly considered in the borderline hip. [Table: see text]
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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 source (direct Gemma or distilled Codex), 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".