scholarly journals Computed tomographic analysis of cervical spine pedicles in the adult Indian population

2021 ◽  
Vol 12 ◽  
pp. 68
Author(s):  
Sanjeev Kumar ◽  
Naresh Kumar Saini ◽  
Devender Singh ◽  
Manish Chadha ◽  
Gopesh Mehrotra
Keyword(s):  
Cervical Spine ◽  
Indian Population ◽  
Three Dimensional ◽  
Pedicle Screws ◽  
Anatomical Variations ◽  
Ct Scans ◽  
Screw Insertion ◽  
Spine Pathology ◽  
Cervical Pedicle ◽  
The Mean

Background: Cervical pedicle screw insertion is a technically demanding procedure that carries the risk of catastrophic damage to surrounding neurovascular structures. Here, we analyzed computed tomography (CT)-based three-dimensional cervical spine pedicle geometry to determine the level and sex-specific morphologic differences in the adult Indian population. Methods: The CT scans of 200 patients (2400 pedicles) without significant cervical spine pathology were collected. The mean pedicle width (PW), pedicle height (PH), pedicle axial length (PAL), and pedicle transverse angle (PTA) from C2 to C7 were measured. Results: The smallest mean PW was at C3 in both males (4.85 ± 0.73 mm) and females (4.31 ± 0.43 mm); 7.08% of all pedicles were found to have mean PW of <4 mm. The smallest mean PH was at C5 in both males (6.25 ± 0.67mm) and females (5.54 ± 0.52 mm). The smallest mean PAL was at C2 in both males (27.46 ± 1.69mm) and females (25.90 ± 1.88 mm). The mean PW, PH, and PAL were significantly greater in males than females at all levels (P < 0.05). The smallest mean PTA was at C3 in males (41.79 ± 2.53°) and at C7 in females (42.40 ± 2.27°). Conclusion: In the adult Indian population, the PW, PH and PAL were smaller than in the typical western population. Females had even smaller PW, PH and PAL as compared to males. We recommend that a small inventory of 3.5mm screws between 20mm to 30mm length be used in most cases where cervical pedicle screws are being used in the Indian population. However, individual vertebrae should be screened preoperatively with CT scans to exclude gross anatomical variations, especially in females and at the C3 and C4 levels.

scholarly journals Patient-Matched 3-D-Printed Guides for the Insertion of Cervical Pedicle Screws in Tumor Surgery

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
C.-E. Heyde ◽  
G. Osterhoff ◽  
Spiegl UJA ◽  
A. Völker ◽  
N. H. von der Höh ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Ct Scan ◽  
Pedicle Screw ◽  
Pedicle Screws ◽  
Patient Specific ◽  
Screw Insertion ◽  
Pedicle Screw Insertion ◽  
Intraoperative Fluoroscopy ◽  
Cervical Pedicle ◽  
Cervical Pedicle Screws

Background. Pedicle screw fixation in the cervical spine provides biomechanical advantages compared to other stabilization techniques. However, pedicle screw insertion in this area is challenging due to the anatomical conditions with a high risk of breaching the small pedicles and violating the vertebral artery or neural structures. Today, several techniques to facilitate screw insertion and to make the procedure safer are used. 3-D-printed patient-matched guides based on a CT reconstruction are a helpful technique which allows to reduce operation time and to improve the safety of pedicle screw insertion at the cervical spine. Cases. 3-D-printed patient-matched drill guides based on a CT scan with a 3-D reconstruction of the spine were used in two challenging cervical spine surgical tumor cases to facilitate the implantation of the pedicle screws. The screw position was controlled postoperatively by means of the routinely performed CT scan. Results. Postoperative imaging (conventional radiographs and CT scan) revealed the correct position of the pedicle screws. The time needed for screw insertion was short, and the need for intraoperative fluoroscopy could be reduced. There was no intra- or postoperative complication related to the pedicle screw implantation. Both tumors could be removed completely. Conclusion. These preliminary results show that 3-D-printed patient-specific guides are a promising tool to support and facilitate the implantation of cervical pedicle screws. The time needed for insertion is short, and intraoperative fluoroscopy time can be reduced. This technique allows for both a meticulous preoperative planning and a correct and therefore safe intraoperative positioning of cervical spine pedicle screws.

scholarly journals Novel Landmark for Cervical Pedicle Screw Insertion Point from Computed Tomography-Based Study

2017 ◽  
Vol 11 (1) ◽  
pp. 82-87 ◽  
Author(s):  
Kazuya Nishizawa ◽  
Kanji Mori ◽  
Akira Nakamura ◽  
Shinji Imai
Keyword(s):  
Cervical Spine ◽  
Pedicle Screw ◽  
Sagittal Plane ◽  
Pedicle Screws ◽  
Degenerative Changes ◽  
Insertion Point ◽  
Cervical Pedicle Screw ◽  
Screw Insertion ◽  
Pedicle Screw Insertion ◽  
Cervical Pedicle

<sec><title>Study Design</title><p>Cross-sectional study.</p></sec><sec><title>Purpose</title><p>The purpose of this study was to evaluate a novel landmark for the cervical pedicle screw insertion point.</p></sec><sec><title>Overview of Literature</title><p>To improve the accuracy of pedicle screw placement, several studies have employed the lateral mass, lateral vertical notch, and/or inferior articular process as landmarks; however, we often encounter patients in whom we cannot identify accurate insertion points for pedicle screws using these landmarks because of degenerative changes in the facet joints. The superomedial edge of the lamina is less affected by degenerative changes, and we hypothesized that it could be a new landmark for identifying an accurate cervical pedicle screw insertion point.</p></sec><sec><title>Methods</title><p>A total of 327 consecutive patients, who had undergone neck computed tomographic scanning for determination of neck disease in our institute, were included in the study. At first, the line was drawn parallel to the superior border of the pedicle in the sagittal plane and parallel to the vertical body in the coronal plane. The line was moved downward in 1-mm increments to the inferior border of the pedicle. We determined whether the line passing through the superomedial edge of the lamina (termed the “N-line”) was located between the superior and inferior borders of the pedicle in the sagittal plane.</p></sec><sec><title>Results</title><p>The percentages of N-lines located between the superior and inferior borders of the pedicle were 100% at C3, 100% at C4, 99% at C5, 96% at C6, and 97% at C7. The lower cervical spine has the higher N-line location.</p></sec><sec><title>Conclusions</title><p>The N-line was frequently located at the level of the pedicle of each cervical spine in the sagittal plane. The superomedial edge of the lamina could be a new landmark for the insertion point of the cervical pedicle screw.</p></sec>

The vertebral artery and the cervical pedicle: morphometric analysis of a critical neighborhood

2010 ◽  
Vol 13 (1) ◽  
pp. 52-60 ◽  
Author(s):  
Andre Tomasino ◽  
Karishma Parikh ◽  
Heiko Koller ◽  
Walter Zink ◽  
A. John Tsiouris ◽  
...  
Keyword(s):  
Vertebral Artery ◽  
Ct Angiography ◽  
Posterior Instrumentation ◽  
Pedicle Screws ◽  
Safe Zone ◽  
Transverse Foramen ◽  
Sagittal Diameter ◽  
Entry Points ◽  
Cervical Pedicle ◽  
The Mean

Object The purpose of this retrospective study was to quantify the anatomical relationship between the vertebral artery (VA), the cervical pedicle, and its surrounding structures, including the incidence of irregularities. Additionally, data delineating a “safe zone,” and these data's application during instrumentation with transpedicular cervical screw fixation were considered. The anatomical proximity of the VA to the cervical pedicle prevents spine surgeons from preferring cervical pedicle screws (CPSs) over lateral mass screws at levels C3–6. Accurate placement of CPSs is often difficult to determine, because this definition can vary between 1 and 4 mm of lateral “noncritical” and “critical” pedicle breaches. No previous study in a western population has investigated the VA's proximity to the cervical pedicle, its percentage of occupancy in the transverse foramen (TF), and the incidence of irregular VA pathways. Methods One hundred twenty-seven consecutive patients who underwent CT angiography of the neck were enrolled in this study. The measurements included the following: medial pedicle border to VA; lateral pedicle border to VA; pedicle diameter (PD); sagittal diameter of the VA; coronal diameter of the VA; sagittal diameter of the TF; and coronal diameter of the TF. The cross-sections of the VA and the TF were measured to determine the occupation ratio of the VA. In addition, a safe zone was defined based on all lateral pedicle border to VA measurements in which the VA was within the TF. The level of entry of the VA into the TF as well as irregularities of the VA and the cervical pedicles were recorded. Results Vertebral artery dominance on the left side was seen in 69.3% of cases. The mean PD increased from 4.9 to 6.5 mm (from C-3 to C-7, respectively). Statistically significantly bigger PDs were seen in males. The mean PD at C-2 was 5.6 mm. Entry of the VA at C-6 was seen in approximately 80% of cases. The TF occupation ratio of the VA was found to be the greatest in C-4 and C-7 (37.1 and 74.2%, respectively). The safe zone increased from C-2 to C-6 (1.1 to 1.7 mm, respectively), but was only 0.65 mm at C-7. In 23.6% of cases, an irregular pathway of the VA or irregular anatomy of a cervical pedicle was seen, with the highest incidence of irregularities found at C-2. Conclusions Computed tomography angiography is a valuable tool that can help determine the relationships between cervical pedicles and the VA as well as irregular VA pathways. Pedicle diameter, safe zone, and occupational ratio of the VA in the foramen determine the risk associated with instrumentation and should be assessed individually. Based on the authors' measurements, C-4 and C-7 can be considered critical levels for CPS placement. Because of this and the high incidence of irregular VA pathways and different entry points, it may be helpful to review neck CT angiography studies before considering posterior instrumentation procedures in the cervical spine.

Three-dimensional fluoroscopy-guided percutaneous thoracolumbar pedicle screw placement

2003 ◽  
Vol 99 (3) ◽  
pp. 324-329 ◽  
Author(s):  
Langston T. Holly ◽  
Kevin T. Foley
Keyword(s):  
Pedicle Screw ◽  
Three Dimensional ◽  
Pedicle Screws ◽  
Screw Placement ◽  
Content Type ◽  
Image Guided ◽  
Spinal Navigation ◽  
Mean Diameter ◽  
The Mean ◽  
Fine Print

✓ The authors sought to evaluate the feasibility and accuracy of three-dimensional (3D) fluoroscopic guidance for percutaneous placement of thoracic and lumbar pedicle screws in three cadaveric specimens. After attaching a percutaneous dynamic reference array to the surgical anatomy, an isocentric C-arm fluoroscope was used to obtain images of the region of interest. Light-emitting diodes attached to the C-arm unit were tracked using an electrooptical camera. The image data set was transferred to the image-guided workstation, which performed an automated registration. Using the workstation display, pedicle screw trajectories were planned. An image-guided drill guide was passed through a stab incision, and this was followed by sequential image-guided pedicle drilling, tapping, and screw placement. Pedicle screws of various diameters (range 4–6.5 mm) were placed in all pedicles greater than 4 mm in diameter. Postoperatively, thin-cut computerized tomography scans were obtained to determine the accuracy of screw placement. Eighty-nine (94.7%) of 94 percutaneous screws were placed completely within the cortical pedicle margins, including all 30 lumbar screws (100%) and 59 (92%) of 64 thoracic screws. The mean diameter of all thoracic pedicles was 6 mm (range 2.9–11 mm); the mean diameter of the five pedicles in which wall violations occurred was 4.6 mm (range 4.1–6.3 mm). Two of the violations were less than 2 mm beyond the cortex; the others were between 2 and 3 mm. Coupled with an image guidance system, 3D fluoroscopy allows highly accurate spinal navigation. Results of this study suggest that this technology will facilitate the application of minimally invasive techniques to the field of spine surgery.

Use of Cervicothoracic Junction Pedicle Screws for Reconstruction of Complex Cervical Spine Pathology

Spine ◽  
1998 ◽  
Vol 23 (14) ◽  
pp. 1596-1599 ◽  
Author(s):  
Todd J. Albert ◽  
Gregg R. Klein ◽  
Denise Joffe ◽  
Alexander R. Vaccaro
Keyword(s):  
Cervical Spine ◽  
Pedicle Screws ◽  
Cervicothoracic Junction ◽  
Spine Pathology

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 Coccygeal Morphology on Multislice Computed Tomography in a Tertiary Hospital in India

2017 ◽  
Vol 11 (5) ◽  
pp. 694-699 ◽  
Author(s):  
Venkatraman Indiran ◽  
Vadivalagianambi Sivakumar ◽  
Prabakaran Maduraimuthu
Keyword(s):  
Computed Tomography ◽  
Indian Population ◽  
Normal Population ◽  
Tertiary Hospital ◽  
Cross Sectional Study ◽  
Ct Scans ◽  
Type I ◽  
Cross Sectional ◽  
Ethnic Populations ◽  
The Mean

<sec><title>Study Design</title><p>A retrospective, cross-sectional study of 213 patients who presented for abdominal computed tomography (CT) scans to assess coccygeal morphology in the Indian population.</p></sec><sec><title>Purpose</title><p>There have been relatively few studies of coccygeal morphology in the normal population and none in the Indian population. We aimed to estimate coccygeal morphometric parameters in the Indian population.</p></sec><sec><title>Overview of Literature</title><p>Coccygeal morphology has been studied in European, American, Korean, and Egyptian populations, with few differences in morphology among populations.</p></sec><sec><title>Methods</title><p>A retrospective analysis of 213 abdominal CT scans (114 males and 99 females; age, 7–88 years; mean age, 47.3 years) was performed to evaluate the number of coccygeal segments, coccyx type, sacrococcygeal and intercoccygeal fusion and subluxation, coccygeal spicules, sacrococcygeal straight length, and sacrococcygeal and intercoccygeal curvature angles. Results were analyzed for differences in morphology with respect to sex and coccyx type.</p></sec><sec><title>Results</title><p>Types I and II coccyx were the most common. Most subjects had four coccygeal vertebrae; 93 subjects (43.66%) had partial or complete sacrococcygeal fusion. Intercoccygeal fusion was common, occurring in 193 subjects. Eighteen subjects had coccygeal spicules. The mean coccygeal straight length was 33.8 mm in males and 31.5 mm in females; the mean sacrococcygeal curvature angle was 116.6° in males and 111.6° in females; the mean intercoccygeal curvature angle was 140.94° in males and 145.10° in females.</p></sec><sec><title>Conclusions</title><p>Type I was the most common coccyx type in our study, as in Egyptian and Western populations. The number of coccygeal vertebrae and prevalence of sacrococcygeal and intercoccygeal fusion in the Indian population were similar to those in the Western population. The mean coccygeal straight length and mean sacrococcygeal curvature angle were higher in males, whereas the intercoccygeal curvature angle was higher in females. Information on similarities and differences in coccygeal morphology between different ethnic populations could be useful in imaging and treating patients presenting with coccydynia.</p></sec>

scholarly journals Application of a three-dimensional virtual model to study the effect of fluoroscopic angle on infra-acetabular corridor parameters and screw insertion rates

2021 ◽  
Author(s):  
Nengfeng Ma ◽  
Xufeng Hu ◽  
Zhoushan Tao ◽  
Min Yang
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
Reference Plane ◽  
Virtual Model ◽  
Screw Insertion ◽  
Pelvic Inlet ◽  
Line Angle ◽  
The Mean ◽  
Type Of Fracture ◽  
Tomography Data

Abstract Purpose To use three-dimensional (3D) virtual models to study how the parameters and insertion rates of the infra-acetabular corridor (IAC) change under different fluoroscopic angles. Methods The pelvis computed tomography data of 187 patients are imported into Mimics software in DICOM format to generate a 3D model. The anterior pelvis plane is used as the reference plane to measure the diameter of the optimum IAC when the pelvis model is tilted forward by 5°, 15°, 25°, 35° and 45°. The diameter of at least 3.5 mm is defined as the cutoff for placing a 3.5 mm screw, the rate of infra-acetabular screw (IAS) insertion is calculated, and the mean length of the IAC and the mean tilt of the corridor axis in relation to the sagittal midline plane (SMP) are measured. Results The similar diameters of the IAC can be found under fluoroscopy at 5°–35°, with the largest diameter of 4.08 ± 1.84 mm and the highest screw insertion rate of 60.42% at 15° and 25°, whereas the diameter and insertion rate are lowest at 45°. The corridor length increases with increasing fluoroscopic angle, and the angle of the corridor axis to the SMP decreases gradually. Conclusions The traditional 45° pelvic inlet radiograph is not suitable as the fluoroscopic angle for IAS insertion. The parameters of the IAC vary according to a certain rule under different fluoroscopic angles, so a surgeon can select the appropriate fluoroscopic angle in accordance with the type of fracture and the fracture line angle.

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