Computer-aided analysis for optimal screw insertion in lateral mass of C1: An anatomical study
Autor: | Paul Puchwein, Renate Krassnig, Jakob Andrea Orlandi, Ellen Tackner, Gloria Hohenberger |
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Rok vydání: | 2017 |
Předmět: |
Adult
Male Jefferson fracture medicine.medical_treatment Vertebral artery Trauma Surgery Bone Screws Fracture Fixation Internal 03 medical and health sciences C1 0302 clinical medicine Cervical spine medicine.artery Multidetector Computed Tomography medicine Humans Orthopedics and Sports Medicine Spinal canal 030222 orthopedics business.industry General Medicine Anatomy Middle Aged medicine.disease Sagittal plane Vertebra Transverse plane Spinal Fusion medicine.anatomical_structure Surgery Computer-Assisted Spinal fusion Cervical Vertebrae Spinal Fractures Female Surgery business Lateral mass screw 030217 neurology & neurosurgery Cervical vertebrae |
Zdroj: | Archives of Orthopaedic and Trauma Surgery |
ISSN: | 1434-3916 0936-8051 |
Popis: | Introduction Motion preserving techniques in C1 ring fractures are increasingly used especially in young patients. Therefore, lateral mass screws are inserted in the first vertebra and connected by a rod. The purpose of this study was to determine safe zones regarding the vertebral arteries and the medulla oblongata for optimal lateral mass screw positioning when fusing the C1-ring. Materials and methods Images of the cervical spine of 50 patients (64-line CT scanner) were evaluated and virtual screws were positioned in both lateral masses of the first vertebra using 3D-reconstructions of CT scans. The length of the screws, the insertion angles in two planes, the distance to the vertebral artery, and the spinal canal was investigated. Descriptive statistics was used and gender-dependent differences were calculated using student t-test. A diameter of 4 mm was chosen for the screws. Results The mean screw length was 30.0 ± 2.3 mm on the right and 30.1 ± 2.1 mm on the left side. The arithmetic mean for the transverse angle was 16.4 ± 5.6° on the right and 15.6 ± 6.3° on the left, the sagittal angle averaged 8.3 ± 3.8° on the right, and 11.0 ± 4.9° on the left side. The mean distance between screw and spinal canal has been determined on the right with 2.4 ± 0.7 mm and 2.2 ± 0.6 mm on the left side. The distance from the C1 lateral mass screw to the vertebral artery was on average 7.1 ± 1.5 mm on the right side (significant correlation with gender, p value: 0.03) and 7.4 ± 1.4 mm on the left side. Conclusions Screws should be positioned with a slightly converging angle of 16° and a slightly ascending angle of 10°. Due to the required high precision technique intraoperatively multiplanar 2 D or 3 D imaging is recommended to avoid harm to the vertebral artery or the spinal canal. |
Databáze: | OpenAIRE |
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