THE CAM DEFORMITY IN PATIENTS WITH FEMOROACETABULAR IMPINGEMENT DEMONSTRATES LOSS OF PROTEOGLYCAN CONTENT
Notice bibliographique
Résumé
Summary Statement This study quantifies compositional differences in cartilage between CAM deformities of symptomatic FAI patients and normal cadaver controls. It shows a resemblance of CAM-FAI cartilage with those of osteoarthritic hips, objectively supporting previous hypothesis of abnormal contact stresses in CAM-FAI. Introduction Degeneration of cartilage within articular joints is a pathological feature of osteoarthritis (OA). Femoroacetabular impingement (FAI), a condition of abnormal contact between the articular surfaces of the femur and acetabulum, has been widely associated with early onset OA of the hip. The purpose of this study was to quantitatively compare the proteoglycan (PG) content of the weight-bearing cartilage in surgical FAI patients versus those of cadavers without FAI. Patients and Methods Osteochondral bone plugs were taken from the antero-superior weight-bearing surface of cam-deformities on the femoral heads of 11 surgical cam-FAI patients. These were compared to control specimens taken from 11 cadaveric hips (7 donors) at approximately the same location. The PG content of the specimens were then histologically compared using the model presented by Martin et al. In this method, Safranin-O binds to chondroitin sulfate, a PG abundant in cartilage, allowing it to be visualised and quantitatively compared. Specifically, the specimens were fixed in formalin, decalcified in EDTA and then sectioned to 7um thick. They were then stained with Safranin-O, which binds specifically and stoichiometrically with proteoglycan. This model allows for quantitative comparison of PG content whereby the red content (R c ) of the sample is linearly correlated with the amount of PG present in the sample when viewed under 4x microscopic magnification. Here, the red content was sampled by depth coordinate with superficial and deep zones analyzed. Results In general, the R C in the cartilage of surgical patients was lower than that of the cadaveric controls in both the superficial and deep layers tested. This correlates to a decrease in the PG of the test subjects. In the surgical specimens, R C ranged from 0 – 31.9 in the superficial layer and 0 – 139.6 in the deep. When compared by layers, the R C of the superficial 30% specimens averaged an R C of 17.5 compared to 88.6 in the cadaveric controls. This represents an 80.2% depletion in the PG content. In the deep 70% layer, the average R C of the test subjects was 52.4, compared with 129.2 in the cadaveric controls. This represents a 59% depletion in the PG content of the deep layer. These results show large compositional change in the cartilage of surgical FAI versus control specimens that were statistically significant in all levels (superficial, deep, total yielding p Discussion The idea of abnormal cartilage at the cam deformity has been previously demonstrated through similar resection and staining techniques. Wagner et al showed cellular activity and qualitatively noted PG depletion in the cartilage on the Cam deformity, consistent with OA. However a quantitative assessment of PG content provides a better estimate of impingement severity and disease state. Results from this current study objectively corroborate previously obtained qualitative data, supporting existing hypothesis of abnormal contact stresses in cam-FAI while giving a more robust, objective quantification of cartilage breakdown at CAM sites.
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Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,003 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».