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Background Context: Cervical pedicle screw (CPS) insertion is technically demanding and carries a risk of serious neurovascular complications when screws perforate. To avoid such serious risks, we currently perform CPS insertion using a computed tomography (CT)-guided navigation system. However, there remains a low probability of screw perforation during CPS insertion that is affected by factors such as CPS insertion angle and anatomical pedicle transverse angle (PTA).
Purpose: This study aimed to understand the perforation tendencies of CPS insertion angles in relation to anatomical PTA.
Study Design: This is a retrospective chart review.
Patient Sample: The study enrolled 151 consecutive patients (95 men and 56 women, with a mean age of 64.6 years).
Outcome Measures: Anatomical PTA and CPS insertion angles were evaluated by axial CT images.
Methods: The medical records of 151 consecutive patients who underwent CPS insertion using a CT-based navigation system were reviewed. We examined the relationships between PTA and CPS insertion angle on axial CT images according to vertebral level.
Results: The average preoperative PTA at each vertebral level was 32.1° for C2, 41.5° for C3, 41.0° for C4, 39.4° for C5, 34.4° for C6, and 27.3° for C7. Corresponding CT-determined pedicle screw insertion angles were 24.9°, 31.3°, 28.7°, 27.8°, 28.0°, and 26.0°, respectively. The CPS insertion angles at C2-C6 were significantly smaller than those for PTA (p<.01). In evaluations of angle thresholds from C3 to C5 that predicted a higher risk of perforation, the receiver operating characteristic curve analysis determined CPS insertion angles of <24.5° and >36.5° for the identification of lateral and medial perforations, respectively.
Conclusion: For CPS insertion into the C3-C5 pedicles using CT, there is an increased likelihood of lateral or medial perforation for insertion angles of <24.5° or >36.5°, respectively.
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http://dx.doi.org/10.1016/j.spinee.2016.08.025 | DOI Listing |
PLoS One
August 2025
Department of Orthopaedics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
Background: Lateral mass screw (LMS) is a more widely adopted method for posterior cervical spine fixation than the cervical pedicle screw (CPS). Despite its lower pullout strength, the insertions of LMS are more reproducible and have a lower risk. CPS insertion is a technically demanding procedure due to the small pedicle channel.
View Article and Find Full Text PDFGlobal Spine J
August 2025
Neurosurgery Unit, Department of Neuroscience "Rita Levi Montalcini", "Città Della Salute e Della Scienza" University Hospital, University of Turin, Italy.
Study DesignRetrospective comparative study.ObjectiveThis multicenter European study aimed to compare the accuracy, complication rates, and incidence of revision surgery associated with three distinct cervical pedicle screw (CPS) insertion techniques: freehand, navigation-assisted (Loop-X/O-arm), and patient-specific 3D-template guided approaches. The primary endpoint was to provide evidence to support decision-making in cervical spine instrumentation.
View Article and Find Full Text PDFIntroduction Cervical pedicle screw (CPS) fixation offers superior biomechanical stability in the management of cervical spine pathologies. However, the technique is associated with a significant risk of screw malposition due to the small pedicle dimensions and the lateralized trajectory of conventional entry points, often complicated by medial paraspinal muscular force. This study aimed to evaluate the safety and accuracy of a novel, medially-shifted cervical pedicle entry point (CPEP) for sub-axial CPS placement utilizing intraoperative O-arm™-based navigation (Medtronic, Minneapolis, USA).
View Article and Find Full Text PDFSpine Surg Relat Res
May 2025
Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Introduction: Cervical pedicle screw (CPS) placement is crucial for posterior cervical fusion surgery due to its strong fixation ability. However, CPS insertion is associated with risks, including screw perforation, which can lead to complications such as vertebral artery injury and neurological deficits. Although previous studies have explored some morphological factors affecting CPS placement, comprehensive data on specific parameters contributing to perforation remains limited.
View Article and Find Full Text PDFPurpose: Cervical pedicle screws (CPS) inserted with template-guided systems (TGS) have a low perforation rate. However, only a few case studies have been reported, and the risk factors for perforation remain unknown. This study aimed to evaluate the accuracy of CPS placement using TGS in a large case series and analyze the risk factors for CPS perforation.
View Article and Find Full Text PDF