Notice bibliographique
Résumé
Wrist fractures can be difficult to treat due to advanced age of the patient, medical co-morbidities, and comminution of bone. In addition, cerclage wires remain the current standard of care following median sternotomy, despite significant complications including dehiscence and infection. Glass polyalkenoate cements (GPCs) have been widely used in dentistry and ear, nose, and throat (ENT) applications but have yet to be indicated for orthopaedic applications. This dissertation focuses on the development of novel GPCs to improve on current treatments for distal radial fixation and sternal fixation. Two injectable GPCs, derived from either glass A (mole fraction: SiO2:0.48, ZnO:0.36, CaO0.12, SrO: 0.04), Glass B (mole fraction: SiO2:0.48, ZnO:0.355, CaO:0.06, SrO:0.08, P2O5:0.02, Ta2O5:0.005), or Glass C (mole fraction: SiO2:0.48, ZnO:0.351, CaO:0.073, SrO:0.143, P2O5:0.027) were investigated using both sternal and radial cadaveric models. Radii fixated with a GPC were ~60% as strong as their intact biological pair when tested to failure. Radii fixated with a GPC were found to be significantly stiffer than their biological pairs fixated with a volar locking plate when tested under fatigue. Further, midline sternal displacement for adhesive-enhanced sternal closures were significantly less than standard wire cerclage. Novel GPCs were investigated in a sheep model by filling a non-critical defect. The GPCs were derived from either Glass A or Glass B at a particle size of <45 m, with a cement formulation consisting of [10g glass : 4g (poly)acrylic acid : 6ml water : 0.75g Trisodium Citrate]. The GPCs demonstrated significant bone resorption surrounding the material and were deemed non-viable in-vivo formulations. The cause of the resorption was believed to be the persistent inflammatory reaction surrounding numerous degraded GPC fragments given that debris release has been observed to cause bone resorption in studies related to polyethylene biomaterials. As a result, the GPC formulation derived from Glass A was improved by increasing the PAA molecular weight from 50k to 210k Mw, increasing the glass particle size from 20-45 m to 45-63 m and reducing the P:L ratio from 1:1 to 1:0.6. The improved GPC (GPC+) was investigated in a rabbit model, followed by a sheep model, by filling a non-critical defect. MicroCT images from all three GPC+ samples in the rabbit model did not show any bone resorption, while histology slides showed normal bone turnover. In the sheep model, five of seven GPC+ samples were associated with mild bone resorption, occurring because of increased osteoclast activity. However, two samples in sheep exhibited no resorption and appeared to stimulate increased bone density at the implant site. The in-vivo response with regards to GPC+ was more favorable than in the previous in-vivo trial. To the best knowledge of the candidate, this dissertation is the first to report a GPC formulated using a glass particle size of 45–63 m, a GPC investigated for sternal and distal radial fixation using a cadaveric model, as well as the biocompatibility of a GPC using a sheep model.
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 | 0,000 |
| 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) | 0,001 | 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 ».