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Feasibility and accuracy of new insertion technique of S1 transpedicular screw. Computed tomography-based morphometric analysis
Affiliations- Department of Orthopedic and Traumatology, W. Dega University Hospital, Poznań, Poland
- Department of Neurosurgery, Specialist Medical Center, Polanica-Zdroj, Poland
- Department of Spine Surgery, Oncology, Orthopedics and Traumatology, W. Dega University Hospital, Poznań, Poland
- Faculty of Mechanical Engineering, Wroclaw University of Technology, Wrocław, Poland
- Department of Human Anatomy, Medical University of Silesia, Katowice, Poland
- Wrocław University of Environmental and Life Sciences, The Faculty of Veterinary Medicine, Wroclaw, Poland
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Abstract
To assess feasibility and accuracy of a new insertion technique of S1 transpedicular screw.
Summary of background dataTranspedicular stabilization in the first sacral vertebra (S1) is a technically demanding surgical procedure with inherent risk of loosening of the implant. A modification of the technique was recently proposed, along with the analytical verification which was performed based on the available literature. In the study, we performed radiological assessment of screws inserted into the S1 using the classical and modified techniques.
MethodsThe analysis was performed in two parts. The first part was performed on eight cadaver specimens after implantation of the screws. In the second part, we used computed tomography images of patients with degenerative disk disease with a superimposed representation of screws. The thickness of the posterior cortex adherent to the screws, screw trajectory and their position with regard to the spinal canal was measured. The area of posterior cortex in contact with the screws was also calculated.
ResultsThe contact length and area was found to be two times greater for screws introduced with the modified technique. The convergence angle was comparable between the techniques, despite the shift of entry point. There was no canal breach, although with the modified technique the screws passed closer to the spinal canal.
ConclusionsThe modified technique is considered safe. In this technique, the screws pass through a thicker portion of the posterior cortex compared to the classical technique that aims at improving the stability of the fixation.
Abstract
To assess feasibility and accuracy of a new insertion technique of S1 transpedicular screw.
Summary of background dataTranspedicular stabilization in the first sacral vertebra (S1) is a technically demanding surgical procedure with inherent risk of loosening of the implant. A modification of the technique was recently proposed, along with the analytical verification which was performed based on the available literature. In the study, we performed radiological assessment of screws inserted into the S1 using the classical and modified techniques.
MethodsThe analysis was performed in two parts. The first part was performed on eight cadaver specimens after implantation of the screws. In the second part, we used computed tomography images of patients with degenerative disk disease with a superimposed representation of screws. The thickness of the posterior cortex adherent to the screws, screw trajectory and their position with regard to the spinal canal was measured. The area of posterior cortex in contact with the screws was also calculated.
ResultsThe contact length and area was found to be two times greater for screws introduced with the modified technique. The convergence angle was comparable between the techniques, despite the shift of entry point. There was no canal breach, although with the modified technique the screws passed closer to the spinal canal.
ConclusionsThe modified technique is considered safe. In this technique, the screws pass through a thicker portion of the posterior cortex compared to the classical technique that aims at improving the stability of the fixation.
Keywords
Anatomy, Pedicle screw, Sacrum, Entry point
About this articleTitle
Feasibility and accuracy of new insertion technique of S1 transpedicular screw. Computed tomography-based morphometric analysis
Journal
Neurologia i Neurochirurgia Polska
Issue
Pages
363-369
Page views
323
Article views/downloads
595
DOI
10.1016/j.pjnns.2016.06.005
Bibliographic record
Neurol Neurochir Pol 2016;50(5):363-369.
Keywords
Anatomy
Pedicle screw
Sacrum
Entry point
Authors
Łukasz Kubaszewski
Grzegorz Miękisiak
Andrzej Nowakowski
Celina Pezowicz
Grzegorz Bajor
Zdzisław Kiełbowicz
Wojciech Kinda
Magdalena Wojtków
Jacek Kaczmarczyk
