Bicortical Laminar Screws for Posterior Fixation of Subaxial Cervical Spine: A Radiologic Analysis With Computed Tomography Images

Study Design: Retrospective radiological analysis. Objectives: Translaminar screw (TLS) placement is one of the fixation techniques in the subaxial cervical spine. However, it can be difficult to use in small diameter of the lamina. This study proposed a novel bicortical laminar screw (BLS) and analyzed the related parameters using computed tomography (CT). Methods: Cervical CT images taken at our institution from January 2013 to March 2017 were used for measurement. On the axial images, the maximum screw length (MSL) and trajectory angle (TA) of BLS and TLS were measured, together with the distance from the midline (DM) to the BLS entry point and the lamina width (LW). On the parasagittal images, the height of the lamina (LH) was measured. Results: MSL of BLS and TLS were 21.00 and 20.97 mm, 19.02 and 20.91 mm, 18.45 and 21.01 mm, and 20.00 and 21.01 mm in C3, C4, C5, and C6, respectively. TA of the BLS and TLS were 21.24° and 34.90°, 19.05° and 34.22°, 18.65° and 33.61°, and 18.30° and 34.51° at C3, C4, C5, and C6, respectively. DM were 6.44, 5.77, 5.68, and 6.03 at C3, C4, C5, and C6, respectively. LW and LH were 3.52 and 12.44 mm, 2.87 and 12.49 mm, 2.76 and 12.42 mm, and 3.18 and 13.30 mm at C3, C4, C5, and C6, respectively. Conclusion: We suggest that BLS fixation is a feasible alternative option for posterior fixation to the lamina of the subaxial cervical spine. It may be especially useful when pedicle screw, lateral mass screw, and TLS are not appropriate.

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Computed Tomography- and Radiography-Based Morphometric Analysis of the Lateral Mass of the Subaxial Cervical Spine in the Indian Population

Asian Spine Journal ◽

10.4184/asj.2018.12.1.18 ◽

2018 ◽

Vol 12 (1) ◽

pp. 18-28

Author(s):

Nirmal D Patil ◽

Sudhir K Srivastava ◽

Sunil Bhosale ◽

Shaligram Purohit

Keyword(s):

Computed Tomography ◽

Cervical Spine ◽

Indian Population ◽

Tertiary Care ◽

X Rays ◽

Lateral Mass ◽

Cross Sectional ◽

X Ray ◽

Subaxial Cervical Spine ◽

Screw Length

<sec><title>Study Design</title>This was a double-blinded cross-sectional study, which obtained no financial support for the research.</sec><sec><title>Purpose</title>To obtain a detailed morphometry of the lateral mass of the subaxial cervical spine.</sec><sec><title>Overview of Literature</title>The literature offers little data on the dimensions of the lateral mass of the subaxial cervical spine.</sec><sec><title>Methods</title>We assessed axial, sagittal, and coronal computed tomography (CT) cuts and anteroposterior and lateral X-rays of the lateral mass of the subaxial cervical spine of 104 patients (2,080 lateral masses) who presented to a tertiary care public hospital (King Edward Memorial Hospital, Mumbai) in a metropolitan city in India.</sec><sec><title>Results</title>For a majority of the parameters, males and females significantly differed at all levels (<italic>p</italic><0.05). Females consistently required higher (<italic>p</italic><0.05) minimum lateral angulation and lateral angulation. While the minimum lateral angulation followed the order of C5<C4<C6<C3, the lateral angulation followed the order of C3<C5<C4<C6. The lateral mass becomes longer and narrower from C3 to C7. In axial cuts, the dimensions increased from C3 to C6. The sagittal cut thickness and diagonal length increased and the sagittal cut height decreased from C3 to C7. The sagittal cut height was consistently lower in the Indian population at all levels, especially at the C7 level, as compared with the Western population, thereby questioning the acceptance of a 3.5-mm lateral mass screw. A good correlation exists between X-ray- and CT-based assessments of the lateral mass.</sec><sec><title>Conclusions</title>Larger lateral angulation is required for Indian patients, especially females. The screw length can be effectively calculated by analyzing the lateral X-ray. A CT scan should be reserved for specific indications, and a caution must be exercised while inserting C7 lateral mass screws.</sec>

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Posterior Fixation Techniques in the Subaxial Cervical Spine

Cureus ◽

10.7759/cureus.338 ◽

2015 ◽

Cited By ~ 4

Author(s):

Ahmer Ghori ◽

Hai V Le ◽

Heeren Makanji ◽

Thomas Cha

Keyword(s):

Cervical Spine ◽

Posterior Fixation ◽

Subaxial Cervical Spine ◽

Fixation Techniques

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Posterior Subaxial Cervical Spine Screw Fixation: A Review of Techniques

Global Spine Journal ◽

10.1177/2192568218759940 ◽

2018 ◽

Vol 8 (7) ◽

pp. 751-760 ◽

Cited By ~ 7

Author(s):

Andrei Fernandes Joaquim ◽

Marcelo Luis Mudo ◽

Lee A. Tan ◽

K. Daniel Riew

Keyword(s):

Cervical Spine ◽

Literature Review ◽

Screw Fixation ◽

Surgical Techniques ◽

Pedicle Screw Fixation ◽

Lateral Mass ◽

Modified Technique ◽

Screw Insertion ◽

Subaxial Cervical Spine ◽

Fixation Techniques

Study Design: A narrative literature review. Objectives: To review the surgical techniques of posterior screw fixation in the subaxial cervical spine. Methods: A broad literature review on the most common screw fixation techniques including lateral mass, pedicle, intralaminar and transfacet screws was performed on PubMed. The techniques and surgical nuances are summarized. Results: The following techniques were described in detail and presented with illustrative figures, including (1) lateral mass screw insertion: by Roy-Camille, Louis, Magerl, Anderson, An, Riew techniques and also a modified technique for C7 lateral mass fixation; (2) pedicle screw fixation technique as described by Abumi and also a freehand technique description; (3) intralaminar screw fixation; and finally, (4) transfacet screw fixation, as described by Takayasu, DalCanto, Klekamp, and Miyanji. Conclusions: Many different techniques of subaxial screw fixation were described and are available. To know the nuances of each one allows surgeons to choose the best option for each patient, improving the success of the fixation and decrease complications.

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Translaminar Screw Fixation in the Subaxial Cervical Spine

Spine ◽

10.1097/brs.0b013e31824c70ef ◽

2012 ◽

Vol 37 (12) ◽

pp. E745-E751 ◽

Cited By ~ 18

Author(s):

Matthew D. Alvin ◽

Kalil G. Abdullah ◽

Michael P. Steinmetz ◽

Daniel Lubelski ◽

Amy S. Nowacki ◽

...

Keyword(s):

Cervical Spine ◽

Screw Fixation ◽

Subaxial Cervical Spine ◽

Translaminar Screw Fixation ◽

Translaminar Screw

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Insertion Angle of Pedicle Screws in the Subaxial Cervical Spine: The Analysis of Computed Tomography-Navigated Insertion of Pedicle Screws

Asian Spine Journal ◽

10.31616/asj.2019.0053 ◽

2020 ◽

Vol 14 (1) ◽

pp. 66-71

Author(s):

Stavros Oikonomidis ◽

Frank Beyer ◽

Carolin Meyer ◽

Christoph Tobias Baltin ◽

Peer Eysel ◽

...

Keyword(s):

Computed Tomography ◽

Cervical Spine ◽

Pedicle Screws ◽

Insertion Angle ◽

Subaxial Cervical Spine

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Anatomy and biomechanics of the craniovertebral junction

Neurosurgical FOCUS ◽

10.3171/2015.1.focus14807 ◽

2015 ◽

Vol 38 (4) ◽

pp. E2 ◽

Cited By ~ 39

Author(s):

Alejandro J. Lopez ◽

Justin K. Scheer ◽

Kayla E. Leibl ◽

Zachary A. Smith ◽

Brian J. Dlouhy ◽

...

Keyword(s):

Cervical Spine ◽

Large Degree ◽

Axial Rotation ◽

Craniovertebral Junction ◽

Anatomical Structures ◽

Complex Combination ◽

Subaxial Cervical Spine ◽

Flexion Extension ◽

Fixation Techniques ◽

Vascular Structures

The craniovertebral junction (CVJ) has unique anatomical structures that separate it from the subaxial cervical spine. In addition to housing vital neural and vascular structures, the majority of cranial flexion, extension, and axial rotation is accomplished at the CVJ. A complex combination of osseous and ligamentous supports allow for stability despite a large degree of motion. An understanding of anatomy and biomechanics is essential to effectively evaluate and address the various pathological processes that may affect this region. Therefore, the authors present an up-to-date narrative review of CVJ anatomy, normal and pathological biomechanics, and fixation techniques.

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Subaxial lateral mass prosthesis for posterior reconstruction of cervical spine

Journal of Neurological Surgery Part A Central European Neurosurgery ◽

10.1055/a-1739-2488 ◽

2022 ◽

Author(s):

Qiang Jian ◽

Zhenlei Liu ◽

Wanru Duan ◽

Fengzeng Jian ◽

Zan Chen

Keyword(s):

Cervical Spine ◽

Joint Angle ◽

Facet Joint ◽

Posterior Fixation ◽

Lateral Mass ◽

Subaxial Cervical Spine ◽

Fixation Plate ◽

The Stability ◽

Posterior Reconstruction ◽

Surface Angle

Purpose: To obtain the relevant morphometry of the lateral mass of the subaxial cervical spine (C3-C7) and to design a series of lateral mass prostheses for the posterior reconstruction of the stability of cervical spine. Methods: The computed tomography (CT) scans of healthy volunteers were obtained. RadiAnt DICOM Viewer software (Version 2020.1, Medixant, Poland) was used to measure the parameters of lateral mass, such as height, anteroposterior dimension (APD), mediolateral dimension (MLD) and facet joint angle. According to the parameters, a series of cervical lateral mass prostheses were designed. Cadaver experiment was conducted to demonstrate its feasibility. Results: 23 volunteers with an average age of 30.1 ± 7.1 years were enrolled in this study. The height of lateral mass is 14.1 mm averagely. Facet joint angle, APD and MLD of lateral mass averaged 40.1 degrees, 11.2 mm and 12.18 mm, respectively. With these key data, a lateral mass prosthesis consists of a bone grafting column and a posterior fixation plate was designed. The column has a 4.0 mm radius, 41 degrees surface angle and adjustable height of 13, 15, or 17 mm. In the cadaver experiment, the grafting column could function as a supporting structure between adjacent facets, and it would not violate exiting nerve root (NR) or vertebral artery (VA). Conclusion: This study provided detailed morphology of the lateral mass of subaxial cervical spine. A series of subaxial cervical lateral mass prostheses were designed awaiting further clinical application.

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Treatment of Injuries to the Subaxial Cervical Spine: Recommendations of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU)

Global Spine Journal ◽

10.1177/2192568217745062 ◽

2018 ◽

Vol 8 (2_suppl) ◽

pp. 25S-33S ◽

Cited By ~ 5

Author(s):

Philipp Schleicher ◽

Philipp Kobbe ◽

Frank Kandziora ◽

Matti Scholz ◽

Andreas Badke ◽

...

Keyword(s):

Computed Tomography ◽

Cervical Spine ◽

Facet Joint ◽

Posterior Instrumentation ◽

Pedicle Screws ◽

German Society ◽

Vertebral Body Replacement ◽

Cervical Spine Injuries ◽

Subaxial Cervical Spine ◽

Spine Injuries

Study Design: Expert consensus. Objectives: To establish treatment recommendations for subaxial cervical spine injuries based on current literature and the knowledge of the Spine Section of the German Society for Orthopaedics and Trauma. Methods: This recommendation summarizes the knowledge of the Spine Section of the German Society for Orthopaedics and Trauma. Results: Therapeutic goals are a stable, painless cervical spine and protection against secondary neurologic damage while retaining maximum possible motion and spinal profile. The AOSpine classification for subaxial cervical injuries is recommended. The Canadian C-Spine Rule is recommended to decide on the need for imaging. Computed tomography is the favoured modality. Conventional x-ray is preserved for cases lacking a “dangerous mechanism of injury.” Magnetic resonance imaging is recommended in case of unexplained neurologic deficit, prior to closed reduction and to exclude disco-ligamentous injuries. Computed tomography angiography is recommended in high-grade facet joint injuries or in the presence of vertebra-basilar symptoms. A0-, A1- and A2-injuries are treated conservatively, but have to be monitored for progressive kyphosis. A3 injuries are operated in the majority of cases. A4- and B- and C-type injuries are treated surgically. Most injuries can be treated with anterior plate stabilization and interbody support; A4 fractures need vertebral body replacement. In certain cases, additive or pure posterior instrumentation is needed. Usually, lateral mass screws suffice. A navigation system is advised for pedicle screws from C3 to C6. Conclusions: These recommendations provide a framework for the treatment of subaxial cervical spine Injuries. They give advice about diagnostic measures and the therapeutic strategy.

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The V2 segment of the vertebral artery: anatomical considerations and surgical implications

Journal of Neurosurgery Spine ◽

10.3171/2011.7.spine1132 ◽

2011 ◽

Vol 15 (6) ◽

pp. 610-619 ◽

Cited By ~ 14

Author(s):

Vittorio M. Russo ◽

Francesca Graziano ◽

Maria Peris-Celda ◽

Antonino Russo ◽

Arthur J. Ulm

Keyword(s):

Cervical Spine ◽

Vertebral Artery ◽

Preoperative Imaging ◽

Neurosurgical Procedures ◽

Lateral Mass ◽

Modified Technique ◽

Intervertebral Disc Space ◽

Disc Space ◽

Subaxial Cervical Spine ◽

Screw Length

Object Iatrogenic injury of the V2 segment of the vertebral artery (VA) is a rare but serious complication and can be catastrophic. The purpose of this study was to characterize the relationship of the V2 segment of the VA to the surrounding anatomical structures and to highlight the potential site and mechanisms of injury that can occur during common neurosurgical procedures involving the subaxial cervical spine. Methods Ten adult cadaveric specimens (20 sides) were included in this study. Quantitative anatomical measurements between selected landmarks and the VA were obtained. In addition, lateral mass screws were placed bilaterally, from C-3 to C-7, reproducing either the Magerl technique or a modified technique. The safety angle, defined as the axial deviation from the screw trajectory needed to injure the VA, and the distance from the entry point to the VA were measured at each level for both techniques. Results The VA coursed closer to the midline at C3–4 and C4–5 (mean distance [SD] 14.9 ± 1.1 mm) than at C2–3 or C5–6. Within the intertransverse space it coursed closer to the uncinate processes of the vertebral bodies (1.8 ± 1.1 mm) than to the anterior tubercle of the transverse processes (3.4 ± 1.6 mm). The distance between the VA and the uncinate process was less at C3–6 (1.3 ± 0.7 mm) than at C2–3 (3.3 ± 0.8 mm). The VA coursed on average at a distance of 11.9 ± 1.7 mm from the anterior and 4.2 ± 2.6 mm from the posterior aspect of the intervertebral disc space. Lateral mass screw angles were 25° lateral and 39.1° cranial for the Magerl technique, and 36.6° lateral and 46.1° cranial for the modified technique. The safety angle was greater and screw length longer when using this modified technique. Conclusions The relation of the V2 segment of the VA to anterior procedures and lateral mass instrumentation at the subaxial cervical spine was reviewed in this study. A detailed anatomical knowledge of the V2 segment of the VA combined with careful preoperative imaging is mandatory for safe cervical spine surgery.

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