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

2007 ◽  
Vol 6 (5) ◽  
pp. 479-484 ◽  
Author(s):  
Takashi Yamazaki ◽  
Ko Matsudaira

✓ 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.

2021 ◽  
Vol 12 ◽  
pp. 518
Author(s):  
Mohamed M. Arnaout ◽  
Magdy O. ElSheikh ◽  
Mansour A. Makia

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.


2010 ◽  
Vol 13 (4) ◽  
pp. 509-515 ◽  
Author(s):  
Cary Idler ◽  
Kevin W. Rolfe ◽  
Josef E. Gorek

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.


2021 ◽  
Vol 11 (17) ◽  
pp. 7801
Author(s):  
Tae Sik Goh ◽  
Sung-Chan Shin ◽  
Hyun-Keun Kwon ◽  
Eui-Suk Sung ◽  
Se Bin Jun ◽  
...  

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.


2019 ◽  
Vol 80 (04) ◽  
pp. 269-276
Author(s):  
Eleftherios Archavlis ◽  
Florian Ringel ◽  
Sven Kantelhardt

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.


2014 ◽  
Vol 20 (2) ◽  
pp. 196-203 ◽  
Author(s):  
Alexander Mason ◽  
Renee Paulsen ◽  
Jason M. Babuska ◽  
Sharad Rajpal ◽  
Sigita Burneikiene ◽  
...  

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.


2020 ◽  
Vol 32 (6) ◽  
pp. 891-899 ◽  
Author(s):  
Jonathan J. Rasouli ◽  
Brooke T. Kennamer ◽  
Frank M. Moore ◽  
Alfred Steinberger ◽  
Kevin C. Yao ◽  
...  

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.


2018 ◽  
Vol 46 (6) ◽  
pp. 2386-2397 ◽  
Author(s):  
Paerhati Rexiti ◽  
Yakufu Abulizi ◽  
Aikeremujiang Muheremu ◽  
Shuiquan Wang ◽  
Maierdan Maimaiti ◽  
...  

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.


Neurosurgery ◽  
2000 ◽  
Vol 47 (2) ◽  
pp. 530-530 ◽  
Author(s):  
Kevin T. Foley ◽  
Ramesh L. Sahjpaul ◽  
Gerald R. Rodts

2019 ◽  
Vol 18 (5) ◽  
pp. 496-502 ◽  
Author(s):  
Erik Edström ◽  
Gustav Burström ◽  
Rami Nachabe ◽  
Paul Gerdhem ◽  
Adrian Elmi Terander

Abstract BACKGROUND Treatment of several spine disorders requires placement of pedicle screws. Detailed 3-dimensional (3D) anatomic information facilitates this process and improves accuracy. OBJECTIVE To present a workflow for a novel augmented-reality-based surgical navigation (ARSN) system installed in a hybrid operating room for anatomy visualization and instrument guidance during pedicle screw placement. METHODS The workflow includes surgical exposure, imaging, automatic creation of a 3D model, and pedicle screw path planning for instrument guidance during surgery as well as the actual screw placement, spinal fixation, and wound closure and intraoperative verification of the treatment results. Special focus was given to process integration and minimization of overhead time. Efforts were made to manage staff radiation exposure avoiding the need for lead aprons. Time was kept throughout the procedure and subdivided to reflect key steps. The navigation workflow was validated in a trial with 20 cases requiring pedicle screw placement (13/20 scoliosis). RESULTS Navigated interventions were performed with a median total time of 379 min per procedure (range 232-548 min for 4-24 implanted pedicle screws). The total procedure time was subdivided into surgical exposure (28%), cone beam computed tomography imaging and 3D segmentation (2%), software planning (6%), navigated surgery for screw placement (17%) and non-navigated instrumentation, wound closure, etc (47%). CONCLUSION Intraoperative imaging and preparation for surgical navigation totaled 8% of the surgical time. Consequently, ARSN can routinely be used to perform highly accurate surgery potentially decreasing the risk for complications and revision surgery while minimizing radiation exposure to the staff.


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