Effectiveness of the Thoracic Pedicle Screw Placement Using the Virtual Surgical Training System: A Cadaver Study

2018 ◽  
Vol 15 (6) ◽  
pp. 677-685 ◽  
Author(s):  
Yang Hou ◽  
Yanping Lin ◽  
Jiangang Shi ◽  
Huajiang Chen ◽  
Wen Yuan
Keyword(s):  
Pedicle Screw ◽  
Surgical Training ◽  
Pedicle Screws ◽  
Cadaver Study ◽  
Training System ◽  
Screw Placement ◽  
Control Group ◽  
Pedicle Screw Placement ◽  
Thoracic Pedicle Screw ◽  
Screw Penetration

Abstract BACKGROUND The virtual simulation surgery has initially exhibited its promising potentials in neurosurgery training. OBJECTIVE To evaluate effectiveness of the Virtual Surgical Training System (VSTS) on novice residents placing thoracic pedicle screws in a cadaver study. METHODS A total of 10 inexperienced residents participated in this study and were randomly assigned to 2 groups. The group using VSTS to learn thoracic pedicle screw fixation was the simulation training (ST) group and the group receiving an introductory teaching session was the control group. Ten fresh adult spine specimens including 6 males and 4 females with a mean age of 58.5 yr (range: 33-72) were collected and randomly allocated to the 2 groups. After exposing anatomic structures of thoracic spine, the bilateral pedicle screw placement of T6-T12 was performed on each cadaver specimen. The postoperative computed tomography scan was performed on each spine specimen, and experienced observers independently reviewed the placement of the pedicle screws to assess the incidence of pedicle breach. RESULTS The screw penetration rates of the ST group (7.14%) was significantly lower in comparison to the control group (30%, P < .05). Statistically significant difference in acceptable rates of screws also occurred between the ST (100%) and control (92.86%) group (P < .05). In addition, the average screw penetration distance in control group (2.37 mm ± 0.23 mm) was significantly greater than ST group (1.23 mm ± 0.56 mm, P < .05). CONCLUSION The virtual reality surgical training of thoracic pedicle screw instrumentation effectively improves surgical performance of novice residents compared to those with traditional teaching method, and can help new beginners to master the surgical technique within shortest period of time.

A comparison of two techniques in image-guided thoracic pedicle screw placement: a retrospective study of 37 patients and 277 pedicle screws

2007 ◽  
Vol 7 (4) ◽  
pp. 393-398 ◽  
Author(s):  
Gregory P. Lekovic ◽  
Eric A. Potts ◽  
Dean G. Karahalios ◽  
Graham Hall
Keyword(s):  
Pedicle Screw ◽  
Image Guidance ◽  
Vascular Complications ◽  
Pedicle Screws ◽  
Guidance System ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
3D Navigation ◽  
Thoracic Pedicle Screw ◽  
Computed Tomography Scanning

Object The goal of this study was to compare the accuracy of thoracic pedicle screw placement aided by two different image-guidance modalities. Methods The charts of 40 consecutive patients who had undergone stabilization of the thoracic spine between January 2003 and January 2005 were retrospectively reviewed. Three patients were excluded from the study because, on the basis of preoperative findings, small pedicle diameter precluded the use of pedicle screws. Thus, a total of 37 patients had 277 screws placed with the aid of either virtual fluoroscopy or isocentric C-arm 3D navigation. The indications for surgery included trauma, degenerative disease, and tumor, and were similar in both groups. All 37 patients underwent postoperative computed tomography scanning, and an independent reviewer graded all screws based on axial, sagittal, and coronal projections for a full determination of the placement of the screw in the pedicle. Results The rate of unintended perforations was found to depend on pedicle diameter (p < 0.0001). There were no statistical differences between groups with regard to rate or grade of cortical perforations. Overall, the rate and grade of perforations was low, and there were no neurological or vascular complications. Conclusions The authors have shown that either image-guidance system may be used with a high degree of accuracy and safety. Because both systems were found to be comparably safe and accurate, the choice of image-guidance modality may be determined by the level of surgeon comfort and/or availability of the system.

Is in vivo manual palpation for thoracic pedicle screw instrumentation reliable?

2014 ◽  
Vol 20 (5) ◽  
pp. 492-496 ◽  
Author(s):  
Miriam L. Donohue ◽  
Ross R. Moquin ◽  
Amit Singla ◽  
Blair Calancie
Keyword(s):  
Pedicle Screw ◽  
Pedicle Screws ◽  
Alternative Methods ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
Thoracic Pedicle Screw ◽  
Thoracic Pedicle Screws ◽  
Screw Position ◽  
Manual Palpation

Object Previous reports on the accuracy of manual palpation for thoracic pedicle screw placement have been restricted to cadaveric studies. Authors of the present novel study assessed the accuracy of manual palpation for the detection of medial and lateral pedicle breaches during thoracic spine surgery in living adult humans. Methods Pedicle tracks were created freehand and manually palpated using a ball-tipped probe. Postoperative CT scans of all implanted thoracic and L-1 screws were evaluated with respect to screw position and the pedicle wall. Results Five hundred twenty-five pedicle track/screw placements were compared. There were 21 pedicles with medial breaches measuring ≥ 2 mm. The surgeon correctly identified only 4 of these pedicle tracks as having a medial breach. The surgeon correctly identified 17 of 128 pedicles with a significant (≥ 2 mm) lateral breach. One hundred two screw placements had no measurable breach in any direction (medial, lateral, or foraminal). The surgeon correctly identified 98% of these ideally placed screws. Conclusions In this real-time study of thoracic pedicle screw placement, the accuracy of manual palpation for detecting medial or lateral breaches that were ≥ 2 mm was disturbingly low. These findings are consistent with those in recent cadaveric evaluations of palpation accuracy and point to the critical need for more reliable alternative methods to assess pedicle integrity during the placement of thoracic pedicle screws for spine instrumentation surgery.

scholarly journals Freehand thoracic pedicle screw technique using a uniform entry point and sagittal trajectory for all levels: preliminary clinical experience

2014 ◽  
Vol 21 (5) ◽  
pp. 778-784 ◽  
Author(s):  
Vernard S. Fennell ◽  
Sheri Palejwala ◽  
Jesse Skoch ◽  
David A. Stidd ◽  
Ali A. Baaj
Keyword(s):  
Pedicle Screw ◽  
Pedicle Screws ◽  
Transverse Process ◽  
Pedicle Screw Fixation ◽  
Entry Point ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
Thoracic Pedicle Screw ◽  
Thoracic Pedicle Screws ◽  
Screw Diameter

Object Experience with freehand thoracic pedicle screw placement is well described in the literature. Published techniques rely on various starting points and trajectories for each level or segment of the thoracic spine. Furthermore, few studies provide specific guidance on sagittal and axial trajectories. The goal of this study was to propose a uniform entry point and sagittal trajectory for all thoracic levels during freehand pedicle screw placement and determine the accuracy of this technique. Methods The authors retrospectively reviewed postoperative CT scans of 33 consecutive patients who underwent open, freehand thoracic pedicle-screw fixation using a uniform entry point and sagittal trajectory for all levels. The same entry point for each level was defined as a point 3 mm caudal to the junction of the transverse process and the lateral margin of the superior articulating process, and the sagittal trajectory was always orthogonal to the dorsal curvature of the spine at that level. The medial angulation (axial trajectory) was approximately 30° at T-1 and T-2, and 20° from T-3 to T-12. Breach was defined as greater than 25% of the screw diameter residing outside of the pedicle or vertebral body. Results A total of 219 thoracic pedicle screws were placed with a 96% accuracy rate. There were no medial breaches and 9 minor lateral breaches (4.1%). None of the screws had to be repositioned postoperatively, and there were no neurovascular complications associated with the breaches. Conclusions It is feasible to place freehand thoracic pedicle screws using a uniform entry point and sagittal trajectory for all levels. The entry point does not have to be adjusted for each level as reported in existing studies, although this technique was not tested in severe scoliotic spines. While other techniques are effective and widely used, this particular method provides more specific parameters and may be easier to learn, teach, and adopt.

Stereotactic Navigation for Placement of Pedicle Screws in the Thoracic Spine

Neurosurgery ◽  
2001 ◽  
Vol 48 (4) ◽  
pp. 771-779 ◽  
Author(s):  
Andrew S. Youkilis ◽  
Douglas J. Quint ◽  
John E. McGillicuddy ◽  
Stephen M. Papadopoulos
Keyword(s):  
Pedicle Screw ◽  
Thoracic Spine ◽  
Medical Center ◽  
Pedicle Screws ◽  
Screw Placement ◽  
Spinal Instability ◽  
Pedicle Screw Placement ◽  
Image Guided ◽  
Thoracic Pedicle Screw ◽  
Thoracic Pedicle Screws

Abstract OBJECTIVE Pedicle screw fixation in the lumbar spine has become the standard of care for various causes of spinal instability. However, because of the smaller size and more complex morphology of the thoracic pedicle, screw placement in the thoracic spine can be extremely challenging. In several published series, cortical violations have been reported in up to 50% of screws placed with standard fluoroscopic techniques. The goal of this study is to evaluate the accuracy of thoracic pedicle screw placement by use of image-guided techniques. METHODS During the past 4 years, 266 image-guided thoracic pedicle screws were placed in 65 patients at the University of Michigan Medical Center. Postoperative thin-cut computed tomographic scans were obtained in 52 of these patients who were available to enroll in the study. An impartial neuroradiologist evaluated 224 screws by use of a standardized grading scheme. All levels of the thoracic spine were included in the study. RESULTS Chart review revealed no incidence of neurological, cardiovascular, or pulmonary injury. Of the 224 screws reviewed, there were 19 cortical violations (8.5%). Eleven (4.9%) were Grade II (≤2 mm), and eight (3.6%) were Grade III (&gt;2 mm) violations. Only five screws (2.2%), however, were thought to exhibit unintentional, structurally significant violations. Statistical analysis revealed a significantly higher rate of cortical perforation in the midthoracic spine (T4–T8, 16.7%; T1–T4, 8.8%; and T9–T12, 5.6%). CONCLUSION The low rate of cortical perforations (8.5%) and structurally significant violations (2.2%) in this retrospective series compares favorably with previously published results that used anatomic landmarks and intraoperative fluoroscopy. This study provides further evidence that stereotactic placement of pedicle screws can be performed safely and effectively at all levels of the thoracic spine.

scholarly journals Image-guid ed thoracic pedicle screw placement: a technical study in cadavers and preliminary clinical experience

2001 ◽  
Vol 10 (2) ◽  
pp. 1-5 ◽  
Author(s):  
Kee D. Kim ◽  
J. Patrick Johnson ◽  
Jesse D. Babbitz
Keyword(s):  
Pedicle Screw ◽  
Image Guidance ◽  
Pedicle Screws ◽  
Guidance System ◽  
Basic Knowledge ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
Image Guided ◽  
Thoracic Pedicle Screw ◽  
Thoracic Pedicle Screws

Object Thoracic pedicle screw fixation is effective and reliable in providing short-segment stabilization. Although the procedure is becoming more widely used, accurate insertion of the screws is difficult due to the small dimensions of thoracic pedicles, and the associated risk is high due to the proximity of the spinal cord. In previous studies authors have shown the accuracy of image-guided lumbar pedicle screw placement, but there have been no reported investigations into the accuracy of image-guided thoracic pedicle screw placement. The authors report their experience with such an investigation. Methods To evaluate the accuracy of image-guided thoracic pedicle screw placement in vitro and in vivo, thoracic pedicle screws were placed with an image-guidance system in five human cadavers and 10 patients. In cadavers, the accuracy of screw placement was assessed by postoperative computerized tomography and visual inspection and in patients by postoperative imaging studies. Of the 120 pedicle screws placed in five cadavers pedicle violation occurred in 23 cases (19.2%); there was one pedicle violation (4.2%) in each of the last two cadavers. Of the 45 pedicle screws placed in 10 patients, pedicle violations occurred in three (6.7%). Conclusions In comparison with historical controls, the accuracy of thoracic pedicle screw placement is improved with the use of an image-guidance system. It allows the surgeon to visualize the thoracic pedicle and the surrounding structures that are normally out of the surgical field of view. The surgeon, however, must be aware of the limitations of an image-guidance system and have a sound basic knowledge of spinal anatomy to avoid causing serious complications.

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 accuracy of pedicle screw placement using intraoperative image guidance systems

2014 ◽  
Vol 20 (2) ◽  
pp. 196-203 ◽  
Author(s):  
Alexander Mason ◽  
Renee Paulsen ◽  
Jason M. Babuska ◽  
Sharad Rajpal ◽  
Sigita Burneikiene ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Image Guidance ◽  
Pedicle Screws ◽  
Screw Placement ◽  
Data Sets ◽  
Pedicle Screw Placement ◽  
Fluoroscopic Image ◽  
Fluoroscopic Navigation ◽  
Guidance Systems ◽  
Accuracy Rates

Object Several retrospective studies have demonstrated higher accuracy rates and increased safety for navigated pedicle screw placement than for free-hand techniques; however, the accuracy differences between navigation systems has not been extensively studied. In some instances, 3D fluoroscopic navigation methods have been reported to not be more accurate than 2D navigation methods for pedicle screw placement. The authors of this study endeavored to identify if 3D fluoroscopic navigation methods resulted in a higher placement accuracy of pedicle screws. Methods A systematic analysis was conducted to examine pedicle screw insertion accuracy based on the use of 2D, 3D, and conventional fluoroscopic image guidance systems. A PubMed and MEDLINE database search was conducted to review the published literature that focused on the accuracy of pedicle screw placement using intraoperative, real-time fluoroscopic image guidance in spine fusion surgeries. The pedicle screw accuracy rates were segregated according to spinal level because each spinal region has individual anatomical and morphological variations. Descriptive statistics were used to compare the pedicle screw insertion accuracy rate differences among the navigation methods. Results A total of 30 studies were included in the analysis. The data were abstracted and analyzed for the following groups: 12 data sets that used conventional fluoroscopy, 8 data sets that used 2D fluoroscopic navigation, and 20 data sets that used 3D fluoroscopic navigation. These studies included 1973 patients in whom 9310 pedicle screws were inserted. With conventional fluoroscopy, 2532 of 3719 screws were inserted accurately (68.1% accuracy); with 2D fluoroscopic navigation, 1031 of 1223 screws were inserted accurately (84.3% accuracy); and with 3D fluoroscopic navigation, 4170 of 4368 screws were inserted accurately (95.5% accuracy). The accuracy rates when 3D was compared with 2D fluoroscopic navigation were also consistently higher throughout all individual spinal levels. Conclusions Three-dimensional fluoroscopic image guidance systems demonstrated a significantly higher pedicle screw placement accuracy than conventional fluoroscopy or 2D fluoroscopic image guidance methods.

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.

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