Reconstruction of the Subaxial Cervical Spine Using Lateral Mass and Facet Screw Instrumentation

<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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Use of 3D Navigation in Subaxial Cervical Spine Lateral Mass Screw Insertion

Journal of Neurological Surgery Reports ◽

10.1055/s-0038-1624574 ◽

2018 ◽

Vol 79 (01) ◽

pp. e1-e8 ◽

Cited By ~ 5

Author(s):

Abdullah Arab ◽

Fahad Alkherayf ◽

Adam Sachs ◽

Eugene Wai

Keyword(s):

Cervical Spine ◽

Navigation System ◽

Lateral Mass ◽

3D Navigation ◽

Subaxial Cervical Spine ◽

Navigation Group ◽

Freehand Technique ◽

Significant Difference ◽

Cord Injury ◽

Screw Malposition

Objective Cervical spine can be stabilized by different techniques. One of the common techniques used is the lateral mass screws (LMSs), which can be inserted either by freehand techniques or three-dimensional (3D) navigation system. The purpose of this study is to evaluate the difference between the 3D navigation system and the freehand technique for cervical spine LMS placement in terms of complications. Including intraoperative complications (vertebral artery injury [VAI], nerve root injury [NRI], spinal cord injury [SCI], lateral mass fracture [LMF]) and postoperative complications (screw malposition, screw complications). Methods Patients who had LMS fixation for their subaxial cervical spine from January 2014 to April 2015 at the Ottawa Hospital were included. A total of 284 subaxial cervical LMS were inserted in 40 consecutive patients. Surgical indications were cervical myelopathy and fractures. The screws' size was 3.5 mm in diameter and 8 to 16 mm in length. During the insertion of the subaxial cervical LMS, the 3D navigation system was used for 20 patients, and the freehand technique was used for the remaining 20 patients. We reviewed the charts, X-rays, computed tomography (CT) scans, and follow-up notes for all the patients pre- and postoperatively. Results Postoperative assessment showed that the incidence of VAI, SCI, and NRI were the same between the two groups. The CT scan analysis showed that the screw breakage, screw pull-outs, and screw loosening were the same between the two groups. LMF was less in the 3D navigation group but statistically insignificant. Screw malposition was less in the 3D navigation group compared with the freehand group and was statistically significant. The hospital stay, operative time, and blood loss were statistically insignificant between the two groups. Conclusions The use of CT-based navigation in LMS insertion decreased the rate of screw malpositions as compared with the freehand technique. Further investigations and trials will determine the effect of malpositions on the c-spine biomechanics. The use of navigation in LMS insertion did not show a significant difference in VAI, LMF, SCI, or NRI as compared with the freehand technique.

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Lateral Mass Fixation in the Subaxial Cervical Spine

Journal of Spinal Disorders & Techniques ◽

10.1097/bsd.0000000000000302 ◽

2015 ◽

Vol 28 (7) ◽

pp. 259-263 ◽

Cited By ~ 7

Author(s):

Mark F. Kurd ◽

Paul W. Millhouse ◽

Gregory D. Schroeder ◽

Christopher K. Kepler ◽

Alexander R. Vaccaro

Keyword(s):

Cervical Spine ◽

Lateral Mass ◽

Subaxial Cervical Spine

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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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Lateral Mass Fixation in Subaxial Cervical Spine: Anatomic Review

Global Spine Journal ◽

10.1055/s-0032-1307261 ◽

2012 ◽

Vol 2 (1) ◽

pp. 039-045 ◽

Cited By ~ 11

Author(s):

Elrahmany Mohamed ◽

Zidan Ihab ◽

Anwar Moaz ◽

Nabawi Ayman ◽

Abo-elw Haitham

Keyword(s):

Cervical Spine ◽

Lateral Mass ◽

Subaxial Cervical Spine

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Radiographic and clinical assessment of a freehand lateral mass screw fixation technique: is it always safe in subaxial cervical spine?

The Spine Journal ◽

10.1016/j.spinee.2014.03.046 ◽

2014 ◽

Vol 14 (9) ◽

pp. 2224-2230 ◽

Cited By ~ 3

Author(s):

In-Hoo Ra ◽

Woo-Kie Min

Keyword(s):

Cervical Spine ◽

Clinical Assessment ◽

Screw Fixation ◽

Lateral Mass ◽

Lateral Mass Screw ◽

Fixation Technique ◽

Subaxial Cervical Spine

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Screw-related complications in the subaxial cervical spine with the use of lateral mass versus cervical pedicle screws

Journal of Neurosurgery Spine ◽

10.3171/2013.8.spine13136 ◽

2013 ◽

Vol 19 (5) ◽

pp. 614-623 ◽

Cited By ~ 47

Author(s):

Hiroyuki Yoshihara ◽

Peter G. Passias ◽

Thomas J. Errico

Keyword(s):

Cervical Spine ◽

Vertebral Artery ◽

Preoperative Evaluation ◽

Pedicle Screws ◽

Complication Rates ◽

Lateral Mass ◽

Subaxial Cervical Spine ◽

Number Of Patients ◽

Cervical Pedicle ◽

Cervical Pedicle Screws

Object Lateral mass screws (LMS) have been used extensively with a low complication rate in the subaxial spine. Recently, cervical pedicle screws (CPS) have been introduced, and are thought to provide more optimal stabilization of the subaxial spine in certain circumstances. However, because of the concern for neurovascular injury, the routine use of CPS in this location remains controversial. Despite this controversy, however, there are no articles directly comparing screw-related complications of each procedure in the subaxial cervical spine. The purpose of this study was to evaluate screw-related complications of LMS and CPS in the subaxial cervical spine. Methods A PubMed/MEDLINE and Cochrane Collaboration Library search was executed, using the key words “lateral mass screw” and “cervical pedicle screw.” Clinical studies evaluating surgical procedures of the subaxial cervical spine in which either LMS or CPS were used and complications were reported were included. Studies in which the number of patients who had subaxial cervical spine surgery and the number of screws placed from C-3 to C-7 could not be specified were excluded. Data on screw-related complications of each study were recorded and compared. Results Ten studies of LMS and 12 studies of CPS were included in the analysis. Vertebral artery injuries were slightly but statistically significantly higher with the use of CPS relative to LMS in the subaxial cervical spine. Although the use of LMS was associated with a higher rate of screw loosening, screw pullout, loss of reduction, pseudarthrosis, and revision surgery, this finding was not statistically significant. Conclusions Based on the available literature, it appears that perioperative neurological and late biomechanical complication rates, including pseudarthrosis, are similarly low for both LMS and CPS techniques. In contrast, vertebral artery injuries, although statistically significantly more common when using CPS, are extremely rare with both techniques, which may justify their nonroutine use in select cases. Given the paucity of well-designed studies available, this recommendation may be a reflection of deficiencies in the available studies. Surgeons using either technique should have intimate knowledge of cervical anatomy and an adequate preoperative evaluation for each patient, with the final selection based on individual case requirements and anatomical limitations.

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Analysis of adjacent-segment cervical kinematics: the role of construct length and the dorsal ligamentous complex

Journal of Neurosurgery Spine ◽

10.3171/2019.7.spine19279 ◽

2020 ◽

Vol 32 (1) ◽

pp. 15-22

Author(s):

Daniel Lubelski ◽

Andrew T. Healy ◽

Prasath Mageswaran ◽

Robb Colbrunn ◽

Richard P. Schlenk

Keyword(s):

Cervical Spine ◽

Industrial Robot ◽

Adjacent Segment ◽

Segmental Motion ◽

Lateral Mass ◽

Subaxial Cervical Spine ◽

Flexion Extension ◽

Cervical Kinematics

OBJECTIVELateral mass fixation stabilizes the cervical spine while causing minimal morbidity and resulting in high fusion rates. Still, with 2 years of follow-up, approximately 6% of patients who have undergone posterior cervical fusion have worsening kyphosis or symptomatic adjacent-segment disease. Based on the length of the construct, the question of whether to extend the fixation system to undisrupted levels has not been answered for the cervical spine. The authors conducted a study to quantify the role of construct length and the terminal dorsal ligamentous complex in the adjacent-segment kinematics of the subaxial cervical spine.METHODSIn vitro flexibility testing was performed using 6 human cadaveric specimens (C2–T8), with the upper thoracic rib cage and osseous and ligamentous integrity intact. An industrial robot was used to apply pure moments and to measure segmental motion at each level. The authors tested the intact state, followed by 9 postsurgical permutations of laminectomy and lateral mass fixation spanning C2 to C7.RESULTSConstructs spanning a single level exerted no significant effects on immediate adjacent-segment motion. The addition of a second immobilized segment, however, created significant changes in flexion-extension range of motion at the supradjacent level (+164%). Regardless of construct length, resection of the terminal dorsal ligaments did not greatly affect adjacent-level motion except at C2–3 and C7–T1 (increasing by +794% and +607%, respectively).CONCLUSIONSDorsal ligamentous support was found to contribute significant stability to the C2–3 and C7–T1 segments only. Construct length was found to play a significant role when fixating two or more segments. The addition of a fused segment to support an undisrupted cervical level is not suggested by the present data, except potentially at C2–3 and C7–T1. The study findings emphasize the importance of the C2–3 segment and its dorsal support.

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