INVESTIGATING SITE-SPECIFIC CHANGES IN THE MECHANICAL PROPERTIES OF THE ANNULUS FIBROSUS FOLLOWING DISC HERNIATION
Notice bibliographique
Résumé
Introduction: Disc herniations transpire when the nucleus pulposus (NP) within the intervertebral\ndisc (IVD) breaks through the surrounding annulus fibrosus (AF) (Gooyers et al., 2015). Disc\nherniations have been demonstrated to be a result of cumulative damage brought on by repeated\nflexion under compressive stresses (Aultman et al., 2005). Limited research has investigated the\nchanges in mechanical properties that occur as a consequence of disc herniation to the AF. Further,\nit is not known if these changes are isolated to only the region of the herniation or the entire AF.\nAims: The purpose of the current work is to investigate if site specific changes to the mechanical\nproperties of the AF fibrosus post disc herniation.\nMethods: A total of 30 porcine cervical spines were used (10 control, 10 static, 10 experimental).\nThe C3/4 and C5/6 functional spine units (FSUs) were excised from these spines and randomized\ninto groups via block randomization for each condition. The experimental porcine FSUs were\nloaded into a uniaxial material testing system (MTS Systems Corporation, Eden Prairie, MN,\nUSA) under a compressive load of 1200 N, with repetitive cycles of off-axis bending at 30°, at 0.5\nHz to create herniation in the 10 experimental spines. The static FSUs were also loaded at 1200 N\ncompression but did not undergo repetitive flexion-extension. The control FSUs only underwent\npreloading. The reasoning for the off-axis herniation protocol was to force the migration of the\nnucleus (i.e., prolapse) to one side of the posterolateral region of the AF (Aultman et al, 2005).\nThis yielded a herniated region, and an internal control region of the posterolateral AF. Following\nloading, two AF samples were excised from each of the herniated and the intact regions. Similarly,\nfrom the control FSUs, two AF samples were excised from the left and right posterolateral region\nof the disc. A lamellar adhesion peel test was conducted on one AF sample and a single lamellae\nlayer test was conducted on the other sample using the UStretch (Cellscale, Waterloo, Ontario)4\nand Biotester (Cellscale, Waterloo, Ontario), respectively. Mechanical properties were quantified\nfrom both tests. A two-way repeated measures ANOVA was conducted to examine the main effect\nof condition (experimental, control, and static) and posterolateral side (ipsilateral and contralateral\nsides), and the interaction between these two variables.\nResults: 3/10 of the experimental IVDs showed evidence of nucleus tracking and thus herniation\nin the posterior, and contralateral region to the bending axis. There was a statistically significant\n(p= 0.03) difference in stress at toe region (mPa) when comparing the experimental group to the\ncontrol group. The control group had greater stress (M=0.29 MPa) at toe region than the\nexperimental group (M=0.068 MPa). There was also a statistically significant (p= 0.02) difference\nin strain at toe region (mPa) when comparing the experimental group to the control group. The\ncontrol group had greater strain (M=0.19%) at toe region when compared to the experimental\ngroup (M=0.13%). There was found to be a statistically significant difference between the\ncontralateral and ipsilateral sides of the IVD for peel stiffness regardless of loading condition\n(p=0.01).\nDiscussion/Conclusion: The toe region of the stress-strain curve is where elastin largely\nfunctions. From the current study, it is possible that fatigue-related degradation to the elastin\nfibres occurred, which could have contributed to the separation of lamellae, eventually leading to\nNP prolapse. The shorter toe region in the current study could be explained by damage to the\nelastin fibres in the experimental group, which resulted in a disruption to elastin.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
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 | 0,000 |
| 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 | 0,001 |
| 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) | 0,002 | 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 ».