The Otto Aufranc Award. On the Etiology of the Cam Deformity: A Cross-sectional Pediatric MRI Study
Bibliographic record
Abstract
BACKGROUND: Femoroacetabular impingement (FAI) has been recognized as a common cause of hip pain as well as a cause of hip arthritis, yet despite this, little is known about the etiology of the cam morphology or possible risk factors associated with its development. QUESTIONS/PURPOSES: The purposes of our study were to determine when the cam morphology associated with FAI developed in a cross-sectional cohort study of pediatric patients pre- and postphyseal closure using MRI and whether increased activity level during the period of physeal closure is associated with an increased likelihood that the cam deformity will develop. METHODS: Alpha angles were measured at the 3 o'clock (anterior head-neck junction) and 1:30 (anterosuperior head-neck junction) positions in both hips with a cam deformity defined as an alpha angle ≥ 50.5° at the 3 o'clock position. Forty-four volunteers (88 hips) were studied: 23 with open physes (12 females, mean age 9.7 years; 11 males, age 11.7 years) and 21 with closed physes (five females, age 15.2 years; 16 males, age 16.2 years). Daily activity level using the validated Habitual Activity Estimation Scale was compared for patients in whom cam morphology did and did not develop. RESULTS: None of the 23 (0%) patients prephyseal closure had cam morphology, whereas three of 21 (14%, p = 0.02; all males) postclosure had at least one hip with cam morphology. Daily activity level was higher (p = 0.02) for patients with the cam morphology (7.1 hours versus 2.9 hours). Mean alpha angles at the 3 o'clock head-neck position were 38° (95% confidence interval [CI], 37.2°-39.1°) in the open physes group and 42° (95% CI, 40.16°-43.90°) in the closed physes group; at the 1:30 head-neck position, they were 45° (95% CI, 44.0°-46.4°) in the open physes group and 50° (47.9°-52.3°) in the closed physes group. CONCLUSIONS: The fact that cam morphology was present exclusively in the closed physeal group strongly supports its development during the period of physeal closure with increased activity level as a possible risk factor.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.133 | 0.026 |
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".