Application of a Novel Attachable Magnetic Nerve Stimulating Probe in Intraoperative Lumbar Pedicle Screw Placement: A Porcine Model Study

Pedicle screw instrumentation is a fundamental technique in lumbar spine surgery. However, several complications could occur when placing a pedicle screw, the most serious being damage to the neural structures. We developed an attachable magnetic nerve stimulating probe used for triggered electromyography (t-EMG) to avoid these. This study aimed to investigate the efficacy of this probe for intraoperative neuromonitoring (ION) during lumbar pedicle screw placement in a porcine model. Forty pedicle screws were inserted bilaterally into the pedicles of the fourth and fifth lumbar vertebrae of five pigs; 20 were inserted typically into the pedicle without nerve damage (Group A), and the other 20 were inserted through the broken medial wall of the pedicle to permit contact with the neural structures (Group B). We measured the triggered threshold for pedicle screw placement through the conventional nerve probe and our newly developed magnetic probe. There was no significant difference in the triggered threshold between the two instruments (p = 0.828). Our newly developed magnetic stimulating probe can be attached to a screwdriver, thus preventing real-time screw malpositioning and making it practical and equally safe. This probe could become indispensable in revision spine surgeries with severe adhesions or endoscopic spine surgeries.

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Confirmation of accuracy/inaccuracy of lumbar pedicle screw placement using postoperative computed tomography

Surgical Neurology International ◽

10.25259/sni_290_2021 ◽

2021 ◽

Vol 12 ◽

pp. 518

Author(s):

Mohamed M. Arnaout ◽

Magdy O. ElSheikh ◽

Mansour A. Makia

Keyword(s):

Computed Tomography ◽

Lumbar Spine ◽

Pedicle Screw ◽

Pedicle Screws ◽

Operative Intervention ◽

Screw Placement ◽

Lumbar Spine Surgery ◽

Pedicle Screw Placement ◽

Lumbar Pedicle ◽

Ct Studies

Background: Transpedicular screws are extensively utilized in lumbar spine surgery. The placement of these screws is typically guided by anatomical landmarks and intraoperative fluoroscopy. Here, we utilized 2-week postoperative computed tomography (CT) studies to confirm the accuracy/inaccuracy of lumbar pedicle screw placement in 145 patients and correlated these findings with clinical outcomes. Methods: Over 6 months, we prospectively evaluated the location of 612 pedicle screws placed in 145 patients undergoing instrumented lumbar fusions addressing diverse pathology with instability. Routine anteroposterior and lateral plain radiographs were obtained 48 h after the surgery, while CT scans were obtained at 2 postoperative weeks (i.e., ideally these should have been performed intraoperatively or within 24–48 h of surgery). Results: Of the 612 screws, minor misplacement of screws (≤2 mm) was seen in 104 patients, moderate misplacement in 34 patients (2–4 mm), and severe misplacement in 7 patients (>4 mm). Notably, all the latter 7 (4.8% of the 145) patients required repeated operative intervention. Conclusion: Transpedicular screw insertion in the lumbar spine carries the risks of pedicle medial/lateral violation that is best confirmed on CT rather than X-rays/fluoroscopy alone. Here, we additional found 7 patients (4.8%) who with severe medial/lateral pedicle breach who warranting repeated operative intervention. In the future, CT studies should be performed intraoperatively or within 24–48 h of surgery to confirm the location of pedicle screws and rule in our out medial or lateral pedicle breaches.

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Anatomical and radiologic characteristics of isthmus parameters in guiding pedicle screw placement

Journal of International Medical Research ◽

10.1177/0300060518762986 ◽

2018 ◽

Vol 46 (6) ◽

pp. 2386-2397 ◽

Cited By ~ 1

Author(s):

Paerhati Rexiti ◽

Yakufu Abulizi ◽

Aikeremujiang Muheremu ◽

Shuiquan Wang ◽

Maierdan Maimaiti ◽

...

Keyword(s):

Pedicle Screw ◽

Pedicle Screws ◽

Screw Placement ◽

Lumbar Spine Surgery ◽

X Rays ◽

Pedicle Screw Placement ◽

Chinese Han ◽

Before And After ◽

Placement Accuracy ◽

D Value

Objective To study the clinical application of lumbar isthmus parameters in guiding pedicle screw placement. Methods Lumbar isthmus parameters were measured in normal lumbar x-rays and cadaveric specimens from a Chinese Han population. Distance between the medial pedicle border and lateral isthmus border was recorded as a ‘D’ value and was compared between X-rays and cadavers. Orthopaedic surgeons estimated different distances (2–6 mm) and angles (5–20°), and bias ratios between estimated and real values were compared. Orthopaedic residents placed pedicle screws on cadaveric specimens before and after application of the ‘D’ value, and screw placement accuracy was compared. Results Except for L4 vertebrae, significant differences in the ‘D’ value were found between 25 cadaveric specimens and x-ray films from 120 patients. Distances and angles estimated by 40 surgeons were significantly different from all real values, except 2 mm distance. Accuracy of pedicle screw placement by six orthopaedic residents was significantly improved by applying the ‘D’ value. Conclusions Surgeon estimates of distance were more accurate than angle estimates. Addition of a ‘D’ value to conventional parameters may significantly improve pedicle screw placement accuracy in lumbar spine surgery.

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Accuracy of percutaneous lumbar pedicle screw placement using the oblique or “owl's-eye” view and novel guidance technology

Journal of Neurosurgery Spine ◽

10.3171/2010.4.spine09580 ◽

2010 ◽

Vol 13 (4) ◽

pp. 509-515 ◽

Cited By ~ 35

Author(s):

Cary Idler ◽

Kevin W. Rolfe ◽

Josef E. Gorek

Keyword(s):

Pedicle Screw ◽

Facet Joint ◽

Pedicle Screws ◽

Guidance System ◽

Screw Placement ◽

Pedicle Screw Placement ◽

Screw Insertion ◽

Percutaneous Pedicle Screw ◽

Clinical Series ◽

Lumbar Pedicle

Object This study was conducted to assess the in vivo safety and accuracy of percutaneous lumbar pedicle screw placement using the owl's-eye view of the pedicle axis and a new guidance technology system that facilitates orientation of the C-arm into the appropriate fluoroscopic view and the pedicle cannulation tool in the corresponding trajectory. Methods A total of 326 percutaneous pedicle screws were placed from L-3 to S-1 in 85 consecutive adult patients. Placement was performed using simple coaxial imaging of the pedicle with the owl's-eye fluoroscopic view. NeuroVision, a new guidance system using accelerometer technology, helped align the C-arm trajectory into the owl's-eye view and the cannulation tool in the same trajectory. Postoperative fine-cut CT scans were acquired to assess screw position. Medical records were reviewed for complications. Results Five of 326 screws breached a pedicle cortex—all breaches were less than 2 mm—for an accuracy rate of 98.47%. Five screws violated an adjacent facet joint. All were at the S-1 superior facet and included in a fusion. No screw violated an adjacent mobile facet or disc space. There were no cases of new or worsening neurological symptoms or deficits for an overall clinical accuracy of 100%. Conclusions The owl's-eye technique of coaxial pedicle imaging with the C-arm fluoroscopy, facilitated by NeuroVision, is a safe and accurate means by which to place percutaneous pedicle screws for degenerative conditions of the lumbar spine. This is the largest series reported to use the oblique or owl's-eye projection for percutaneous pedicle screw insertion. The accuracy of percutaneous screw insertion with this technique meets or exceeds that of other reported clinical series or techniques.

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Which of MIS-TLIF and TLIF Can Leads to Better Pedicle Screws Placement Accuracy and Clinical Outcomes with Navigation Guidance?

10.21203/rs.3.rs-558088/v1 ◽

2021 ◽

Author(s):

JiaBin Liu ◽

JunLong Wu ◽

Rui Zuo ◽

ChangQing Li ◽

Chao Zhang ◽

...

Keyword(s):

Minimally Invasive ◽

Pedicle Screw ◽

Pedicle Screws ◽

Entry Point ◽

Screw Placement ◽

Transfusion Rate ◽

Pedicle Screw Placement ◽

Multifidus Muscle ◽

Lower Accuracy ◽

Significant Difference

Abstract Background Although previous studies have suggested that navigation can improve the accuracy of pedicle screw placement, there are still few studies comparing navigation-assisted transforaminal lumbar interbody fusion (TLIF) and navigation-assisted minimally-invasive TLIF (MIS-TLIF). The pedicle screw insertion entry point of navigation-assisted MIS-TLIF may be deflected from the planned entry point due to uneven bone-surface, which may result in misplacement. The purpose of this study was to explore the pedicle screws accuracy and clinical consequences of MIS-TLIF and TLIF both under O-arm navigation to determine which surgical method is better.MethodsA retrospective study of 54 patients who underwent single-segment navigation-assisted MIS-TLIF (NM-TLIF) or navigation-assisted TLIF (N-TLIF) was conducted. In addition to the patient's demographic characteristics, intraoperative indicators and complications, the ODI and VAS scores were recorded and analyzed preoperatively, at 1, 6, 12 months and at the final follow-up postoperatively. The clinical accuracy and absolute accuracy of pedicle screw placement was assessed by postoperative CT. Multifidus muscle injury were evaluated by T2-weighted MRI.ResultsCompared with N-TLIF, NM-TLIF was more advantageous in the incision length, intraoperative blood loss, drainage volume, time before ambulation, length of hospital stays, blood transfusion rate and analgesia rate (p<0.05). The ODI and VAS for low back pain scores were better than those of N-TLIF at 1 month and 6 months after surgery (p<0.05). There was no significant difference in the screw clinical qualitative accuracy (97.3% vs. 96.2%, p>0.05). The absolute quantitative accuracy results show that the axial translational error, sagittal translational error and sagittal angle error of NM-TLIF group are significantly greater than that in N-TLIF group (P<0.05). The mean T2-weighted signal intensity of multifidus muscle in the NM-TLIF group was significantly lower than that in the N-TLIF group (P<0.05)ConclusionsCompared with N-TLIF, NM-TLIF has more minimally invasive advantages, it does not yield a lower accuracy of screw placement and can achieve better symptom relief in the middle stage of postoperative recovery. However，more attention on real-time adjustment should be paid to pedicle insertion in NM-TLIF, rather than just following the entry point and trajectory of the intraoperative plan.

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Diathermy testing: a novel method with electric knife stimulation to avoid nerve injuries during lumbar pedicle screw placement

Journal of Neurosurgery Spine ◽

10.3171/spi.2007.6.5.479 ◽

2007 ◽

Vol 6 (5) ◽

pp. 479-484 ◽

Cited By ~ 2

Author(s):

Takashi Yamazaki ◽

Ko Matsudaira

Keyword(s):

Retrospective Study ◽

Pedicle Screw ◽

Pedicle Screws ◽

Neurological Complications ◽

Screw Placement ◽

Nerve Injuries ◽

Pedicle Screw Placement ◽

Novel Method ◽

Leg Movements ◽

Lumbar Pedicle

✓ The purpose of this retrospective study was to demonstrate the utility of diathermy in avoiding nerve injuries due to misplacement of lumbar pedicle screws (PSs). The authors used diathermy to assess whether a screw deviated from the pedicle by observing synchronous leg movements caused by intermittently touching an electric knife to the pedicular instrument. Diathermy was performed in 259 cases in which 1301 PSs had been placed. Leg movements were observed in 36 cases, and the sensitivity of diathermy was 85.7%, with a specificity of 99.5%. No neurological complications associated with the placement of PSs were observed after adding diathermy testing to conventional methods. Diathermy testing may be a way to avoid nerve injuries during lumbar PS placement.

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Določanje velikosti in vstavitvene trajektorije pedikularnih vijakov v računalniškotomografskih (CT) slikah deformacij prsne hrbtenice: primerjava ročnega in računalniško podprtega predoperacijskega načrtovanja

Slovenian Medical Journal ◽

10.6016/zdravvestn.1747 ◽

2017 ◽

Vol 85 (11-12) ◽

Author(s):

Dejan Knez ◽

Janez Mohar ◽

Robert Janez Cirman ◽

Boštjan Likar ◽

Franjo Pernuš ◽

...

Keyword(s):

Pedicle Screw ◽

Preoperative Planning ◽

Sagittal Plane ◽

Pedicle Screws ◽

Ct Images ◽

Screw Placement ◽

Computer Assisted ◽

Pedicle Screw Placement ◽

Pull Out ◽

Significant Difference

Background: Vertebral fixation by pedicle screw placement is the most frequently applied fixation technique in spinal surgery. In this retrospective study we present a comparison of manual and computer-assisted preoperative planning of pedicle screw placement in three-dimensional (3D) computed tomography (CT) images of deformities in the thoracic spine.Methods: Manual planning of the pedicle screw size and trajectory was performed by two orthopedic surgeons using a dedicated software for preoperative planning of surgical procedures, while computer-assisted planning was performed by automated image processing and analysis techniques through the optimization of screw fastening strength. The size (diameter and length) and trajectory (pedicle crossing point, inclination in the sagittal plane, inclination in the axial plane) were obtained for 316 pedicle screws from 3D CT images of 17 patients with thoracic spinal deformities.Results: the analysis of pedicle screw parameters, obtained by two manual and one computer-assisted planning, indicated a statistically significant diﬀerence in the screw size (p < 0.05) and trajectory (p < 0.001). Computer-assisted planning proposed wider (p < 0.05) and longer (p < 0.001) screws with a higher (p < 0.001) normalized fastening strength.Conclusions: The comparison revealed consistency between manual and computer-assisted planning of the pedicle screw size and trajectory, except for the screw inclination in the sagittal plane, as manual planning followed more the straight-forward while computer-assisted planning followed more the anatomical insertion technique. While being faster, more repeatable and more reliable than manual planning, computer-assisted planning was also linked with a higher screw fastening strength and consequently a higher screw pull-out strength.

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Maintenance of Integrity of Upper Facet Joints during Simulated Percutaneous Pedicle Screw Insertion Using 2D versus 3D Planning

Journal of Neurological Surgery Part A Central European Neurosurgery ◽

10.1055/s-0039-1681042 ◽

2019 ◽

Vol 80 (04) ◽

pp. 269-276

Author(s):

Eleftherios Archavlis ◽

Florian Ringel ◽

Sven Kantelhardt

Keyword(s):

Pedicle Screw ◽

Facet Joint ◽

Pedicle Screws ◽

Entry Point ◽

Screw Placement ◽

Pedicle Screw Placement ◽

Data Set ◽

Screw Insertion ◽

Percutaneous Pedicle Screw ◽

Lumbar Pedicle

Background No studies have directly and quantitatively compared two-dimensional (2D) and three-dimensional (3D) planning as applied during conventional percutaneous or navigated percutaneous pedicle screw placement. Study Aims This lumbar pedicle-based stabilization simulation study aimed to investigate the risk of upper facet joint violation (FJV) during posterior percutaneous pedicle screw placement with conventional 2D planning of screw implantation (as a model for fluoroscopically guided screws) compared with 3D planning (as used with navigation techniques). Methods The placement of monosegmental lumbar pedicle screws using the data sets of 250 consecutive patients was simulated. Conventional surgery (using 2D fluoroscopic images anteroposterior and lateral view) was compared with screw placement using the 3D reconstruction of the planning mode of the same software. Results The 2D planning resulted in 140 upper FJVs (28% of cases), whereas 3D planning resulted in only 24 upper FJVs (4.8% of cases) (p < 0.05). Among those spinal segments with severe facet joint arthropathy, Pathria grades 3 and 4, FJV was significantly higher (p < 0.05) in the 2D-planned screws (64.7%) than in the 3D-planned screws (11.2%). A more lateral (mean distance: 3.5 mm) and inferior (mean distance: 2.5 mm) offset of the pedicle entry point and a larger medial angulation of the trajectory (mean angle: 9 degrees) were observed for the 3D-planned screws at all levels. Conclusion This study demonstrates that the use of 2D planning is associated with a higher risk of upper FJV than when a 3D imaging data set is used. Using a more lateral and inferior entry point for fluoroscopically guided pedicle screws could reduce the rate of FJV in percutaneous pedicle screw placement.

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The accuracy of pedicle screw placement using intraoperative image guidance systems

Journal of Neurosurgery Spine ◽

10.3171/2013.11.spine13413 ◽

2014 ◽

Vol 20 (2) ◽

pp. 196-203 ◽

Cited By ~ 155

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.

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Utility of intraoperative electromyography in placing C7 pedicle screws

Journal of Neurosurgery Spine ◽

10.3171/2019.11.spine191120 ◽

2020 ◽

Vol 32 (6) ◽

pp. 891-899 ◽

Cited By ~ 1

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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