Subaxial Cervical Pedicle Screw Placement With Direct Visualization of Pedicle Borders: 2-Dimensional Operative Video

2021 ◽  
Author(s):  
S Harrison Farber ◽  
Michael A Bohl ◽  
David S Xu ◽  
Juan S Uribe ◽  
U Kumar Kakarla ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Pedicle Screws ◽  
Tactile Feedback ◽  
Screw Placement ◽  
Direct Visualization ◽  
Fusion Construct ◽  
Subaxial Cervical Spine ◽  
Loss Of Resistance ◽  
Cervical Pedicle ◽  
High Degree

Abstract Pedicle screws provide superior fixation of the subaxial cervical spine to other techniques. However, a high degree of accuracy is required for safe placement given the proximity of pedicles to critical neurovascular structures. A variety of techniques are described to maximize accuracy, including freehand, fluoroscopy-guided, and neuronavigation-based methods.  We present a technique for the placement of pedicle screws in the subaxial cervical spine using direct visualization of the pedicle in a patient who required an occipito-cervical fusion construct in the setting of a C2 chordoma. A laminotomy or laminectomy is performed laterally to allow for visualization of the medial, superior, and inferior walls of the pedicle. The entry point for screw placement is determined based on pedicle anatomy and is typically 1 to 2 mm lateral to the midpoint of the lateral mass, just below the base of the superior articulating process. Screw trajectory is determined by visualizing the pedicle borders and is aimed at the junction of the medial pedicle wall, with the posterior vertebral body down the pedicle axis. Tactile feedback (loss of resistance) is used to assess for a breach while drilling. The cannulation is then tapped, and the screw is placed in a standard fashion.  Direct visualization of pedicle anatomy can be a useful adjunct to guide the safe placement of subaxial pedicle screws when superior fixation is required or when normal anatomy is distorted. The technique may be combined with fluoroscopic or navigation-based techniques to provide real-time anatomic guidance during screw placement. The patient provided informed, written consent for this procedure before surgery. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

scholarly journals Utility of intraoperative electromyography in placing C7 pedicle screws

2020 ◽  
Vol 32 (6) ◽  
pp. 891-899 ◽  
Author(s):  
Jonathan J. Rasouli ◽  
Brooke T. Kennamer ◽  
Frank M. Moore ◽  
Alfred Steinberger ◽  
Kevin C. Yao ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Pedicle Screw ◽  
Thoracolumbar Spine ◽  
Pedicle Screws ◽  
Neurological Injury ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
Data Set ◽  
Subaxial Cervical Spine ◽  
Increased Risk

OBJECTIVEThe C7 vertebral body is morphometrically unique; it represents the transition from the subaxial cervical spine to the upper thoracic spine. It has larger pedicles but relatively small lateral masses compared to other levels of the subaxial cervical spine. Although the biomechanical properties of C7 pedicle screws are superior to those of lateral mass screws, they are rarely placed due to increased risk of neurological injury. Although pedicle screw stimulation has been shown to be safe and effective in determining satisfactory screw placement in the thoracolumbar spine, there are few studies determining its utility in the cervical spine. Thus, the purpose of this study was to determine the feasibility, clinical reliability, and threshold characteristics of intraoperative evoked electromyographic (EMG) stimulation in determining satisfactory pedicle screw placement at C7.METHODSThe authors retrospectively reviewed a prospectively collected data set. All adult patients who underwent posterior cervical decompression and fusion with placement of C7 pedicle screws at the authors’ institution between January 2015 and March 2019 were identified. Demographic, clinical, neurophysiological, operative, and radiographic data were gathered. All patients underwent postoperative CT scanning, and the position of C7 pedicle screws was compared to intraoperative neurophysiological data.RESULTSFifty-one consecutive C7 pedicle screws were stimulated and recorded intraoperatively in 25 consecutive patients. Based on EMG findings, 1 patient underwent intraoperative repositioning of a C7 pedicle screw, and 1 underwent removal of a C7 pedicle screw. CT scans demonstrated ideal placement of the C7 pedicle screw in 40 of 43 instances in which EMG stimulation thresholds were > 15 mA. In the remaining 3 cases the trajectories were suboptimal but safe. When the screw stimulation thresholds were between 11 and 15 mA, 5 of 6 screws were suboptimal but safe, and in 1 instance was potentially dangerous. In instances in which the screw stimulated at thresholds ≤ 10 mA, all trajectories were potentially dangerous with neural compression.CONCLUSIONSIdeal C7 pedicle screw position strongly correlated with EMG stimulation thresholds > 15 mA. In instances, in which the screw stimulates at values between 11 and 15 mA, screw trajectory exploration is recommended. Screws with thresholds ≤ 10 mA should always be explored, and possibly repositioned or removed. In conjunction with other techniques, EMG threshold testing is a useful and safe modality in determining appropriate C7 pedicle screw placement.

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

2013 ◽  
Vol 19 (5) ◽  
pp. 614-623 ◽  
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.

scholarly journals The accuracy of a novel pedicle screw insertion technique assisted by a special angular scale in the subaxial cervical spine using lateral mass as a reference marker

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Hang Shi ◽  
Lei Zhu ◽  
Jun Ma ◽  
Yu-Cheng Zhu ◽  
Xiao-Tao Wu
Keyword(s):  
Cervical Spine ◽  
Pedicle Screws ◽  
Ct Images ◽  
Entry Point ◽  
Lateral Mass ◽  
Insertion Technique ◽  
Reference Marker ◽  
Subaxial Cervical Spine ◽  
Angular Scale ◽  
Cervical Pedicle

Abstract Background Posterior cervical pedicle screw (CPS) internal fixation has better biomechanical stability than other posterior cervical fixation methods. However, this technique is limited in clinical practice due to the complex anatomical structure and the adjacent relationship of the cervical pedicle, and the high risk of neurovascular injury. The purpose of this study was to describe a novel subaxial CPS insertion technique assisted by a special angular scale using lateral mass as a reference marker and to evaluate the accuracy of CPS placement and the distribution characteristics of CPS misplacement. Methods A total of 36 patients with subaxial cervical spine diseases who underwent posterior CPS fixation were consecutively selected. The optimal entry point on the posterior surface of the lateral mass was identified on the three-dimensional cervical model reconstructed from preoperative computed tomography (CT) images. The pedicle transverse angle (PTA) and pedicle-lateral mass angle (PLMA) were measured on the transverse and sagittal CT images respectively. The pedicle screws were inserted according to the preoperatively planned entry point and angles. We analysed the postoperative CT images for CPS misplacement rates and perforation directions following the Lee classification. Results Overall, 177 pedicle screws were inserted, of which 119 (67.2%) were classified as grade 0, 43 (24.3%) as grade 1, 12 (6.8%) as grade 2 and 3 (1.7%) as grade 3 by the postoperative CT images. The accuracy rate of CPS placement was 91.5%. Of the 15 misplaced pedicle screws (grades 2 and 3), 11 were lateral pedicle perforations, 3 were superior perforations and 1 was an inferior perforation. There were no neurovascular injuries related to CPS misplacement. Conclusions With our technique, the optimal entry point and two angles (PTA and PLMA) were identified for CPS insertion. The novel CPS insertion technique assisted by a special angular scale provides high accuracy and few complications.

Accuracy of Subaxial Cervical Pedicle Screw Placement Using Direct Visualization Versus Computed Tomography–Based Navigation

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
S. Harrison Farber ◽  
Jakub Godzik ◽  
Randall J. Hlubek ◽  
James J. Zhou ◽  
Corey T. Walker ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Pedicle Screw ◽  
Screw Placement ◽  
Direct Visualization ◽  
Pedicle Screw Placement ◽  
Cervical Pedicle Screw ◽  
Cervical Pedicle

The Safety and Accuracy of Freehand Pedicle Screw Placement in the Subaxial Cervical Spine

Spine ◽  
2014 ◽  
Vol 39 (4) ◽  
pp. 280-285 ◽  
Author(s):  
Jin Hoon Park ◽  
Sang Ryong Jeon ◽  
Sung Woo Roh ◽  
Jeoung Hee Kim ◽  
Seung Chul Rhim
Keyword(s):  
Cervical Spine ◽  
Pedicle Screw ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
Subaxial Cervical Spine

Surgical anatomy of the C-2 pedicle

2001 ◽  
Vol 95 (1) ◽  
pp. 88-92 ◽  
Author(s):  
Jay U. Howington ◽  
John J. Kruse ◽  
Deepak Awasthi
Keyword(s):  
Sagittal Plane ◽  
Pedicle Screws ◽  
Anatomical Study ◽  
Ct Scanning ◽  
Surgical Anatomy ◽  
Screw Placement ◽  
Preoperative Imaging ◽  
Direct Visualization ◽  
Content Type ◽  
Fine Print

Object. The goal of this anatomical study was to investigate the surgical and radiographic anatomy of the C-2 pedicle in relation to transpedicular screw placement in occipitocervical stabilization and to establish anatomical guidelines for the placement of C-2 pedicle screws. Methods. The C-2 pedicles in 10 cadaveric spines were evaluated using both computerized tomography (CT) scanning and manual measurements. The specimens were scanned; the mediolateral and rostrocaudal angulations of each pedicle were measured, with the midline sagittal plane and the inferior endplate of the C-2 facet, respectively, as references, and values were recorded in 1° increments by using a digital goniometer. The height, width, and length of the pedicles were also measured on the CT scans. Based on these measurements in conjunction with direct visualization of the C-2 pedicle through the C1–2 interlaminar space pedicle screws were then placed. The distances from the screw entry point to the midline, C2–3 joint line, and the medial aspect of the vertebral artery were also measured. Repeated CT scanning was then performed to assess screw placement. The average pedicle height, width, and length measured 9.1 mm, 7.9 mm, and 16.6 mm, respectively, and the medial inclination and rostrocaudal angulation averaged 35.2° and 38.8°, respectively. The cortex of the pedicle was not violated in any of the 20 cadaveric specimens. Conclusions. Adequate preoperative imaging studies in conjunction with direct visualization of the C-2 pedicle make transpedicular fixation safe and effective.

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

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

scholarly journals LEVEL OF EVIDENCE IN THE PLACEMENT OF TRANSPEDICULAR SCREWS IN SUBAXIAL CERVICAL SPINE

2016 ◽  
Vol 15 (2) ◽  
pp. 145-150 ◽  
Author(s):  
Cristóbal Herrera Palacios ◽  
Armando Fabio Ramos Guerrero ◽  
Gustavo Casas Martínez ◽  
Alfredo Javier Moheno Gallardo ◽  
Silvestre Fuentes Figueroa
Keyword(s):  
Cervical Spine ◽  
Health Care Professionals ◽  
Pedicle Screws ◽  
High Energy ◽  
Cervical Region ◽  
Level Of Evidence ◽  
Safety And Efficacy ◽  
Subaxial Cervical Spine ◽  
Freehand Technique ◽  
Grade Of Recommendation

ABSTRACT The high-energy trauma mainly involves vertebral lesions and 6% occur in the cervical region. This poses a challenge to spine surgeons in surgical decision-making, both in terms of approach as the instrumentation. International recommendations establish that the procedures performed are reproducible, safe, and effective. The techniques for placement of pedicle screws are complicated and have been based on intraoperative navigation (limited by cost) and fluoroscopy (greater exposure of health care professionals and patients to radiation). Therefore, the freehand technique is an option. The goal was to identify the level of evidence and grade of recommendation in the medical literature regarding the safety and efficacy of pedicle screw instrumentation with freehand technique in subaxial cervical spine. To this end, we carried out a systematic review with the following MeSH terms: safety, efficacy, vertebral artery. Articles were evaluated twice in a standardized and blind way by two observers skilled in systematic analysis, after CLEIS 3401 authorization in November 2014. Due to the nature of the study and the variables, articles with a high level of evidence and grade of recommendation were not found. Level of Evidence obtained on safety and efficacy in the placement of pedicle screws in subaxial column with freehand technique: 2b. Degree of Recommendation obtained on safety and efficacy in the placement of pedicle screws in subaxial column with freehand technique: B, favorable recommendation.

Sign in / Sign up

Export Citation Format

Share Document