Validation of a freehand technique for cortical bone trajectory screws in the lumbar spine
Notice bibliographique
Résumé
OBJECTIVE: The cortical bone trajectory (CBT) technique for pedicle screw placement has gained popularity among spinal surgeons. It has been shown biomechanically to provide better fixation and improved pullout strength compared to a traditional pedicle screw trajectory. The CBT technique also allows for a less invasive approach for fusion and may have lower incidence of adjacent-level disease. A limitation of the current CBT technique is a lack of readily identifiable and reproducible visual landmarks to guide freehand CBT screw placement in comparison to the well-defined identifiable landmarks for traditional pedicle screw insertion. The goal of this study was to validate a safe and intuitive freehand technique for placement of CBT screws based on optimization of virtual CBT screw placement using anatomical landmarks in the lumbar spine. The authors hypothesized that virtual identification of anatomical landmarks on 3D models of the lumbar spine generated from CT scans would translate to a safe intraoperative freehand technique. METHODS: Customized, open-source medical imaging and visualization software (3D Slicer) was used in this study to develop a workflow for virtual simulation of lumbar CBT screw insertion. First, in an ex vivo study, 20 anonymous CT image series of normal and degenerative lumbar spines and virtual screw insertion were conducted to place CBT screws bilaterally in the L1-5 vertebrae for each image volume. The optimal safe CBT trajectory was created by maximizing both the screw length and the cortical bone contact with the screw. Easily identifiable anatomical surface landmarks for the start point and trajectory that best allowed the reproducible idealized screw position were determined. An in vivo validation of the determined landmarks from the ex vivo study was then performed in 10 patients. Placement of virtual "test" cortical bone trajectory screws was simulated with the surgeon blinded to the real-time image-guided navigation, and the placement was evaluated. The surgeon then placed the definitive screw using image guidance. RESULTS: From the ex vivo study, the optimized technique and landmarks were similar in the L1-4 vertebrae, whereas the L5 optimized technique was distinct. The in vivo validation yielded ideal, safe, and unsafe screws in 62%, 16%, and 22% of cases, respectively. A common reason for the nonidealized trajectories was the obscuration of patient anatomy secondary to severe degenerative changes. CONCLUSIONS: CBT screws were placed ideally or safely 78% of the time in a virtual simulation model. A 22% rate of unsafe freehand trajectories suggests that the CBT technique requires use of image-guided navigation or x-ray guidance and that reliable freehand CBT screw insertion based on anatomical landmarks is not reliably feasible in the lumbar spine.
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 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) | 0,000 | 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 tête enseignante, 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 ».