Comparison of computerized tomography and direct visualization in thoracic pedicle screw placement

2002 ◽  
Vol 97 (2) ◽  
pp. 223-226 ◽  
Author(s):  
Ganesh Rao ◽  
Darrel S. Brodke ◽  
Matthew Rondina ◽  
Andrew T. Dailey
Keyword(s):  
Pedicle Screw ◽  
Computerized Tomography ◽  
Predictive Value ◽  
Ct Scanning ◽  
Screw Placement ◽  
Direct Visualization ◽  
Pedicle Screw Placement ◽  
Content Type ◽  
Thoracic Pedicle Screw ◽  
Fine Print

Object. To validate computerized tomography (CT) scanning as a tool to assess the accuracy of thoracic pedicle screw placement, the authors compared its accuracy with that of direct visualization in instrumented cadaveric spine specimens. Methods. A grading scale was devised to score the placement of the pedicle screw. The grades ranged from 0 to 3 depending on the extent to which the pedicle had been violated. One hundred fifty-five pedicles were fitted with instrumentation in eight cadaveric spines. A single observer graded the appearance of the screw based on CT scans (3-mm axial sections with 1-mm overlap) and direct visualization of the specimen. The authors arrived at a Kappa value of 0.51, which suggested only moderate agreement between the two measurement techniques. Whereas CT had a positive predictive value of 95%, it had a negative predictive value of 62%. Conclusions. The authors thus conclude that although CT scanning is the most valid tool to assess the accuracy of thoracic pedicle screw placement, it tends to overestimate the number of misplaced screws.

Thoracic pedicle screws: postoperative computerized tomography scanning assessment

2004 ◽  
Vol 100 (4) ◽  
pp. 325-331 ◽  
Author(s):  
Robert F. Heary ◽  
Christopher M. Bono ◽  
Margaret Black
Keyword(s):  
Computerized Tomography ◽  
Pedicle Screws ◽  
Ct Scanning ◽  
Screw Placement ◽  
Grading System ◽  
Content Type ◽  
Thoracic Pedicle Screws ◽  
Grade Ii ◽  
Grade Iii ◽  
Fine Print

Object. The authors evaluated the accuracy of placement of thoracic pedicle screws by performing postoperative computerized tomography (CT) scanning. A grading system is presented by which screw placement is classified in relation to neurological, bone, and intrathoracic landmarks. Methods. One hundred eighty-five thoracic pedicle screws were implanted in 27 patients with the assistance of computer image guidance or fluoroscopy. Postoperative CT scanning was conducted to determine a grade for each screw: Grade I, entirely contained within pedicle; Grade II, violates lateral pedicle but screw tip entirely contained within the vertebral body (VB); Grade III, tip penetrates anterior or lateral VB; Grade IV, breaches medial or inferior pedicle; and Grade V, violates pedicle or VB and endangers spinal cord, nerve root, or great vessels and requires immediate revision. Based on anatomical morphometry, the spine was subdivided into upper (T1–2), middle (T3–6), and lower (T7–12) regions. Statistical analyses were performed to compare regions. The mean follow-up period was 37.6 months. The following postoperative CT scanning—documented grades were determined: Grade I, 160 screws (86.5%); Grade II, 15 (8.1%); Grade III, six (3.2%); Grade IV, three (1.6%); and Grade V, one (0.5%). Among cases involving screw misplacements, Grade II placement was most common, and this occurred most frequently in the middle thoracic region. Conclusions. The authors' grading system has advantages over those previously described; however, further study to determine its reliability, reproducibility, and predictive value of clinical sequelae is warranted. Postoperative CT scanning should be considered the gold standard for evaluating thoracic pedicle screw placement.

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.

Progressive neurological deficits with benign intracerebral cysts

1986 ◽  
Vol 65 (5) ◽  
pp. 706-709 ◽  
Author(s):  
Yoko Nakasu ◽  
Jyoji Handa ◽  
Kazuyoshi Watanabe
Keyword(s):  
Histological Examination ◽  
Computerized Tomography ◽  
Cyst Wall ◽  
Benign Lesion ◽  
Ct Scanning ◽  
Neurological Deficits ◽  
Review Of The Literature ◽  
Content Type ◽  
Ct Findings ◽  
Fine Print

✓ Two patients with benign intracerebral cysts are reported and a brief review of the literature is given. Although computerized tomography (CT) scanning is useful in detecting a variety of intracerebral cysts, the CT findings are not specific for any lesion. An exploratory operation with establishment of an adequate route of drainage and a histological examination of the cyst wall are mandatory in the management of patients with a progressive but benign lesion.

Variability Analysis of Manual and Computer-Assisted Preoperative Thoracic Pedicle Screw Placement Planning

Spine ◽  
2018 ◽  
Vol 43 (21) ◽  
pp. 1487-1495 ◽  
Author(s):  
Dejan Knez ◽  
Janez Mohar ◽  
Robert J. Cirman ◽  
Boštjan Likar ◽  
Franjo Pernuš ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Screw Placement ◽  
Computer Assisted ◽  
Pedicle Screw Placement ◽  
Variability Analysis ◽  
Thoracic Pedicle Screw

scholarly journals Learning Retention of Thoracic Pedicle Screw Placement Using a High-Resolution Augmented Reality Simulator With Haptic Feedback

2011 ◽  
Vol 69 (suppl_1) ◽  
pp. ons14-ons19 ◽  
Author(s):  
Cristian J Luciano ◽  
P Pat Banerjee ◽  
Brad Bellotte ◽  
G Michael Oh ◽  
Michael Lemole ◽  
...  
Keyword(s):  
Augmented Reality ◽  
Pedicle Screw ◽  
Haptic Feedback ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
Data Set ◽  
Learning Retention ◽  
Performance Accuracy ◽  
Thoracic Pedicle Screw ◽  
Thoracic Pedicle Screws

Abstract BACKGROUND: We evaluated the use of a part-task simulator with 3D and haptic feedback as a training tool for a common neurosurgical procedure - placement of thoracic pedicle screws. OBJECTIVE: To evaluate the learning retention of thoracic pedicle screw placement on a high-performance augmented reality and haptic technology workstation. METHODS: Fifty-one fellows and residents performed thoracic pedicle screw placement on the simulator. The virtual screws were drilled into a virtual patient's thoracic spine derived from a computed tomography data set of a real patient. RESULTS: With a 12.5% failure rate, a 2-proportion z test yielded P = .08. For performance accuracy, an aggregate Euclidean distance deviation from entry landmark on the pedicle and a similar deviation from the target landmark in the vertebral body yielded P = .04 from a 2-sample t test in which the rejected null hypothesis assumes no improvement in performance accuracy from the practice to the test sessions, and the alternative hypothesis assumes an improvement. CONCLUSION: The performance accuracy on the simulator was comparable to the accuracy reported in literature on recent retrospective evaluation of such placements. The failure rates indicated a minor drop from practice to test sessions, and also indicated a trend (P = .08) toward learning retention resulting in improvement from practice to test sessions. The performance accuracy showed a 15% mean score improvement and more than a 50% reduction in standard deviation from practice to test. It showed evidence (P = .04) of performance accuracy improvement from practice to test session.

The use of computerized tomography in the diagnosis of cerebral hydatid cysts

1979 ◽  
Vol 50 (3) ◽  
pp. 339-342 ◽  
Author(s):  
Tuncalp Özgen ◽  
Aykut Erbengi ◽  
Vural Bertan ◽  
Süleyman Saǧlam ◽  
Özdemir Gürçay ◽  
...  
Keyword(s):  
Hydatid Cyst ◽  
Computerized Tomography ◽  
Ct Scanning ◽  
Hydatid Cysts ◽  
Content Type ◽  
Cerebral Hydatid Cyst ◽  
Cyst Membrane ◽  
Fine Print

✓ Eleven cases of cerebral hydatid cyst, diagnosed by computerized tomography (CT), are presented. The importance of CT in minimizing the possibility of accidentally tapping or tearing the cyst membrane is stressed. Repeat CT scanning after removal of the cyst revealed atrophy in the affected hemisphere.

Age-related changes in the proportion of intracranial cerebrospinal fluid space measured using volumetric computerized tomography scanning

2002 ◽  
Vol 97 (3) ◽  
pp. 607-610 ◽  
Author(s):  
Hiroshi Wanifuchi ◽  
Takashi Shimizu ◽  
Takashi Maruyama
Keyword(s):  
Cerebrospinal Fluid ◽  
Computerized Tomography ◽  
Ct Scanning ◽  
Volume Measurement ◽  
Intracranial Volume ◽  
Content Type ◽  
Standard Curve ◽  
Age Related ◽  
Fine Print ◽  
Age Related Changes

Object. The purpose of this study was to establish a standard curve to demonstrate normal age-related changes in the proportion of intracranial cerebrospinal fluid (CSF) space in intracranial volume (ICV) during each decade of life. Methods. Using volumetric computerized tomography (CT) scanning and computer-guided volume measurement software, ICV and cerebral parenchymal volume (CPV) for each decade of life were measured and the intracranial CSF ratio was calculated by the following formula: percentage of CSF = (ICV − CPV)/ICV × 100%. The standard curve for age-related changes in normal percentages of intracranial CSF was obtained. Conclusions. Based on this standard curve, the percentage of intracranial CSF rapidly increased after the sixth decade, seeming to reflect the brain atrophy that accompanies increased age.

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

scholarly journals Anatomic considerations for C2 pedicle screw placement: the use of computerized tomography measurements

2009 ◽  
Vol 8 (1) ◽  
pp. 80-83
Author(s):  
Adebukoa Onibokun ◽  
Simona Bistazzoni ◽  
Marco Sassi ◽  
Larry T. Khoo
Keyword(s):  
Pedicle Screw ◽  
Computerized Tomography ◽  
Preoperative Planning ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
C2 Pedicle Screw ◽  
Anatomical Knowledge ◽  
Axial Ct ◽  
The Mean ◽  
Pedicle Width

OBJECTIVE: more detailed anatomical knowledge of the C2 pedicle is required to optimize and minimize the risk of screw placement. The aim of this study was to evaluate the linear and angular dimensions of the true C2 pedicle using axial CT. METHODS: ninety three patients (47 males, 46 females mean age 48 years) who had cervical spinal CT imaging performed were evaluated for this study. Axial images of the C2 pedicle were selected and the following pedicle parameters were determined: pedicle width (PW, the mediolateral diameter of the pedicle isthmus, perpendicular to the pedicle axis) and pedicle transverse angle (PTA, that is, the angle between the pedicle axis and the midline of the vertebral body). RESULTS: the overall mean pedicle width was 5.8 1.2mm. The mean pedicle width in males (6.01.3mm) was greater than that in the female subjects (5.6 1.1mm). This difference was not found to be statistically significant (p=.6790). The overall mean pedicle transverse angle was 43.93.9 degrees. The mean PTA in males was 43.23.8 degrees, while that in females was 44.73.7 degrees. CONCLUSION: preoperative planning is absolutely mandatory, particularly in determining not only screw trajectory, but in analyzing individual patient anatomy and reception to a C2 pedicle screw.

Successful stereotaxic evacuation of an acute pontomedullary hematoma

1985 ◽  
Vol 62 (1) ◽  
pp. 153-156 ◽  
Author(s):  
D. Andries Bosch ◽  
Gustaaf N. Beute
Keyword(s):  
Arteriovenous Malformation ◽  
Young Woman ◽  
Computerized Tomography ◽  
Ct Scanning ◽  
Vascular Lesion ◽  
Content Type ◽  
Healthy Young Woman ◽  
First Child ◽  
Fine Print

✓ A healthy young woman developed a rapidly progressive pontomedullary lesion 24 hours after delivery of her first child. The lesion was shown on computerized tomography (CT) to be a primary hematoma. Stereotaxic aspiration was carried out, and the patient recovered. Angiography and CT scanning demonstrated a vascular lesion compatible with an arteriovenous malformation.

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