scholarly journals P.174 Accuracy of pedicle screw placement with X-ray versus O-arm image-guided navigation

Author(s):  
L Neuburger ◽  
Y Cheng ◽  
DR Fourney

Background: Image-guided navigation is routinely used in spine surgery to improve placement of pedicle screws. However, most reports have relied on two-dimensional X-ray evaluation to determine accuracy of screw positioning. In this study, computed tomography (CT) and O-arm imaging enabled a detailed three-dimensional comparison of screw placement. The objective was to compare the accuracy of pedicle screw placement with intraoperative X-ray versus O-arm image-guided navigation. Methods: This was a retrospective analysis of image-guided pedicle screw placement in patients who underwent spinal instrumentation. Post-operative CT and O-arm imaging allowed grading of screw accuracy based on pedicle breaches. Clinical outcomes included patient and operative factors. Results: Pedicle screws were placed in 208 patients (1116 screws). Three-dimensional O-arm guidance was utilized for 126 patients, while the remainder underwent two-dimensional X-ray imaging and post-operative CT assessment. O-arm navigation was associated with improved pedicle screw accuracy: pedicle breaches were more likely to be low grade (odds ratio 2.84, p=0.001) and less likely to be medium grade (odds ratio 0.35, p=0.007) or high grade (odds ratio 0.31, p=0.025). Conclusions: This study provided a detailed comparison of surgical accuracy with X-ray versus O-arm guidance. Navigation with O-arm imaging is associated with benefits in spinal instrumentation, without impacting operative risks for patients.

Author(s):  
Xinghuo Wu ◽  
Rong Liu ◽  
Song Xu ◽  
Cao Yang ◽  
Shuhua Yang ◽  
...  

This study aimed to evaluate the safety and accuracy of mixed reality–based intraoperative three-dimensional navigated pedicle screws in three-dimensional printed model of fractured upper cervical spine. A total of 27 cervical model from patients of upper cervical spine fractures formed the study group. All the C1 and C2 pedicle screws were inserted under mixed reality–based intraoperative three-dimensional image-guided navigation system. The accuracy and safety of the pedicle screw placement were evaluated on the basis of postoperative computerized tomography scans. A total of 108 pedicle screws were properly inserted into the cervical three-dimensional models under mixed reality–based navigation, including 54 C1 pedicle screws and 54 C2 pedicle screws. Analysis of the dimensional parameters of each pedicle at C1/C2 level showed no statistically significant differences in the ideal and the actual entry points, inclined angles, and tailed angles. No screw was misplaced outside the pedicle of the three-dimensional printed model, and no ionizing X-ray radiation was used during screw placement under navigation. It is easy and safe to place C1/C2 pedicle screws under MR surgical navigation. Mixed reality–based navigation is feasible within upper cervical spinal fractures with improved safety and accuracy of C1/C2 pedicle screw insertion.


2003 ◽  
Vol 99 (3) ◽  
pp. 324-329 ◽  
Author(s):  
Langston T. Holly ◽  
Kevin T. Foley

✓ 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.


2017 ◽  
Vol 42 (5) ◽  
pp. E14 ◽  
Author(s):  
Granit Molliqaj ◽  
Bawarjan Schatlo ◽  
Awad Alaid ◽  
Volodymyr Solomiichuk ◽  
Veit Rohde ◽  
...  

OBJECTIVEThe quest to improve the safety and accuracy and decrease the invasiveness of pedicle screw placement in spine surgery has led to a markedly increased interest in robotic technology. The SpineAssist from Mazor is one of the most widely distributed robotic systems. The aim of this study was to compare the accuracy of robot-guided and conventional freehand fluoroscopy-guided pedicle screw placement in thoracolumbar surgery.METHODSThis study is a retrospective series of 169 patients (83 women [49%]) who underwent placement of pedicle screw instrumentation from 2007 to 2015 in 2 reference centers. Pathological entities included degenerative disorders, tumors, and traumatic cases. In the robot-assisted cohort (98 patients, 439 screws), pedicle screws were inserted with robotic assistance. In the freehand fluoroscopy-guided cohort (71 patients, 441 screws), screws were inserted using anatomical landmarks and lateral fluoroscopic guidance. Patients treated before 2009 were included in the fluoroscopy cohort, whereas those treated since mid-2009 (when the robot was acquired) were included in the robot cohort. Since then, the decision to operate using robotic assistance or conventional freehand technique has been based on surgeon preference and logistics. The accuracy of screw placement was assessed based on the Gertzbein-Robbins scale by a neuroradiologist blinded to treatment group. The radiological slice with the largest visible deviation from the pedicle was chosen for grading. A pedicle breach of 2 mm or less was deemed acceptable (Grades A and B) while deviations greater than 2 mm (Grades C, D, and E) were classified as misplacements.RESULTSIn the robot-assisted cohort, a perfect trajectory (Grade A) was observed for 366 screws (83.4%). The remaining screws were Grades B (n = 44 [10%]), C (n = 15 [3.4%]), D (n = 8 [1.8%]), and E (n = 6 [1.4%]). In the fluoroscopy-guided group, a completely intrapedicular course graded as A was found in 76% (n = 335). The remaining screws were Grades B (n = 57 [12.9%]), C (n = 29 [6.6%]), D (n = 12 [2.7%]), and E (n = 8 [1.8%]). The proportion of non-misplaced screws (corresponding to Gertzbein-Robbins Grades A and B) was higher in the robot-assisted group (93.4%) than the freehand fluoroscopy group (88.9%) (p = 0.005).CONCLUSIONSThe authors’ retrospective case review found that robot-guided pedicle screw placement is a safe, useful, and potentially more accurate alternative to the conventional freehand technique for the placement of thoracolumbar spinal instrumentation.


2018 ◽  
Vol 28 (4) ◽  
pp. 357-363 ◽  
Author(s):  
Gregory M. Malham ◽  
Rhiannon M. Parker

OBJECTIVEImage guidance for spine surgery has been reported to improve the accuracy of pedicle screw placement and reduce revision rates and radiation exposure. Current navigation and robot-assisted techniques for percutaneous screws rely on bone-anchored trackers and Kirchner wires (K-wires). There is a paucity of published data regarding the placement of image-guided percutaneous screws without K-wires. A new skin-adhesive stereotactic patient tracker (SpineMask) eliminates both an invasive bone-anchored tracker and K-wires for pedicle screw placement. This study reports the authors’ early experience with the use of SpineMask for “K-wireless” placement of minimally invasive pedicle screws and makes recommendations for its potential applications in lumbar fusion.METHODSForty-five consecutive patients (involving 204 screws inserted) underwent K-wireless lumbar pedicle screw fixation with SpineMask and intraoperative neuromonitoring. Screws were inserted by percutaneous stab or Wiltse incisions. If required, decompression with or without interbody fusion was performed using mini-open midline incisions. Multimodality intraoperative neuromonitoring assessing motor and sensory responses with triggered electromyography (tEMG) was performed. Computed tomography scans were obtained 2 days postoperatively to assess screw placement and any cortical breaches. A breach was defined as any violation of a pedicle screw involving the cortical bone of the pedicle.RESULTSFourteen screws (7%) required intraoperative revision. Screws were removed and repositioned due to a tEMG response < 13 mA, tactile feedback, and 3D fluoroscopic assessment. All screws were revised using the SpineMask with the same screw placement technique. The highest proportion of revisions occurred with Wiltse incisions (4/12, 33%) as this caused the greatest degree of SpineMask deformation, followed by a mini midline incision (3/26, 12%). Percutaneous screws via a single stab incision resulted in the fewest revisions (7/166, 4%). Postoperative CT demonstrated 7 pedicle screw breaches (3%; 5 lateral, 1 medial, 1 superior), all with percutaneous stab incisions (7/166, 4%). The radiological accuracy of the SpineMask tracker was 97% (197/204 screws). No patients suffered neural injury or required postoperative screw revision.CONCLUSIONSThe noninvasive cutaneous SpineMask tracker with 3D image guidance and tEMG monitoring provided high accuracy (97%) for percutaneous pedicle screw placement via stab incisions without K-wires.


2021 ◽  
pp. 1-7
Author(s):  
Ann Liu ◽  
Yike Jin ◽  
Ethan Cottrill ◽  
Majid Khan ◽  
Erick Westbroek ◽  
...  

OBJECTIVE Augmented reality (AR) is a novel technology which, when applied to spine surgery, offers the potential for efficient, safe, and accurate placement of spinal instrumentation. The authors report the accuracy of the first 205 pedicle screws consecutively placed at their institution by using AR assistance with a unique head-mounted display (HMD) navigation system. METHODS A retrospective review was performed of the first 28 consecutive patients who underwent AR-assisted pedicle screw placement in the thoracic, lumbar, and/or sacral spine at the authors’ institution. Clinical accuracy for each pedicle screw was graded using the Gertzbein-Robbins scale by an independent neuroradiologist working in a blinded fashion. RESULTS Twenty-eight consecutive patients underwent thoracic, lumbar, or sacral pedicle screw placement with AR assistance. The median age at the time of surgery was 62.5 (IQR 13.8) years and the median body mass index was 31 (IQR 8.6) kg/m2. Indications for surgery included degenerative disease (n = 12, 43%); deformity correction (n = 12, 43%); tumor (n = 3, 11%); and trauma (n = 1, 4%). The majority of patients (n = 26, 93%) presented with low-back pain, 19 (68%) patients presented with radicular leg pain, and 10 (36%) patients had documented lower extremity weakness. A total of 205 screws were consecutively placed, with 112 (55%) placed in the lumbar spine, 67 (33%) in the thoracic spine, and 26 (13%) at S1. Screw placement accuracy was 98.5% for thoracic screws, 97.8% for lumbar/S1 screws, and 98.0% overall. CONCLUSIONS AR depicted through a unique HMD is a novel and clinically accurate technology for the navigated insertion of pedicle screws. The authors describe the first 205 AR-assisted thoracic, lumbar, and sacral pedicle screws consecutively placed at their institution with an accuracy of 98.0% as determined by a Gertzbein-Robbins grade of A or B.


Author(s):  
Praveen Satarasinghe ◽  
D. Kojo Hamilton ◽  
Michael Jace Tarver ◽  
Robert J. Buchanan ◽  
Michael T. Koltz

Object. Utilization of pedicle screws (PS) for spine stabilization is common in spinal surgery. With reliance on visual inspection of anatomical landmarks prior to screw placement, the free-hand technique requires a high level of surgeon skill and precision. Three-dimensional (3D) computer-assisted virtual neuronavigation improves the precision of PS placement and minimize steps. Methods. Twenty-three patients with degenerative, traumatic, or neoplastic pathologies received treatment via a novel three-step PS technique that utilizes a navigated power driver in combination with virtual screw technology. 1) Following visualization of neuroanatomy using intraoperative CT, a navigated 3-mm match stick drill bit was inserted at anatomical entry point with screen projection showing virtual screw. 2) Navigated Stryker Cordless Driver with appropriate tap was used to access vertebral body through pedicle with screen projection again showing virtual screw. 3) Navigated Stryker Cordless Driver with actual screw was used with screen projection showing the same virtual screw. One hundred and forty-four consecutive screws were inserted using this three-step, navigated driver, virtual screw technique. Results. Only 1 screw needed intraoperative revision after insertion using the three-step, navigated driver, virtual PS technique. This amounts to a 0.69% revision rate. One hundred percent of patients had intraoperative CT reconstructed images to confirm hardware placement. Conclusions. Pedicle screw placement utilizing the Stryker-Ziehm neuronavigation virtual screw technology with a three step, navigated power drill technique is safe and effective.


Author(s):  
Xinghuo Wu ◽  
Rong Liu ◽  
Jie Yu ◽  
Lin Lu ◽  
Cao Yang ◽  
...  

Cervical transarticular fixation is a technically demanding procedure. This study aimed to develop a safer and more accurate method for C1/2 pedicle screw placement using a three-dimensional printed drilling guide. A total of 20 patients with C1/2 fractures and dislocations were recruited, and their computed tomography scans were evaluated. Under the assistance of the three-dimensional printed drilling guide, bilateral C1/2 pedicle screws were successfully placed in the three-dimensional C1/2 models. Then, sagittal and axial computed tomography scans were obtained, and the accuracy and safety of screw placement were evaluated based on X-Y-Z axis setup. The average depths for C1 and C2 pedicle screws were 30.1 ± 1.12 and 31.81 ± 0.85 mm on the left side and 29.54 ± 1.01 and 31.35 ± 0.27 mm on the right side, respectively. The average dimensional parameters for C1/C2 pedicle screw of both sides were measured and analyzed, which showed no statistically significant differences in the ideal and the actual entry points, inclined angles, and tailed angles. The method of developing a three-dimensional printed drilling guide is an easy and safe technique. This novel technique is applicable for C1/2 pedicle screw fixation; the potential use of the three-dimensional printed guide to place C1/2 pedicle screw is promising.


Neurosurgery ◽  
2001 ◽  
Vol 48 (4) ◽  
pp. 771-779 ◽  
Author(s):  
Andrew S. Youkilis ◽  
Douglas J. Quint ◽  
John E. McGillicuddy ◽  
Stephen M. Papadopoulos

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.


2014 ◽  
Vol 21 (3) ◽  
pp. 320-328 ◽  
Author(s):  
Mohamad Bydon ◽  
Risheng Xu ◽  
Anubhav G. Amin ◽  
Mohamed Macki ◽  
Paul Kaloostian ◽  
...  

Object A number of imaging techniques have been introduced to minimize the risk of pedicle screw placement. Intraoperative CT has been recently introduced to assist in spinal instrumentation. The aim of this study was to study the effectiveness of intraoperative CT in enhancing the safety and accuracy of pedicle screw placement. Methods The authors included all cases from December 2009 through July 2012 in which intraoperative CT scanning was used to confirm pedicle screw placement. Results A total of 203 patients met the inclusion criteria. Of 1148 screws, 103 screws (8.97%) were revised intraoperatively in 72 patients (35.5%): 14 (18.42%) were revised in the cervical spine (C-2 or C-7), 25 (7.25%) in the thoracic spine, and 64 (8.80%) in the lumbar spine. Compared with screws in the thoracic and lumbar regions, pedicle screws placed in the cervical region were statistically more likely to be revised (p = 0.0061). Two patients (0.99%) required reoperations due to undetected misplacement of pedicle screws. Conclusions The authors describe one of the first North American experiences using intraoperative CT scanning to confirm the placement of pedicle screws. Compared with a similar cohort of patients from their institution who had pedicle screws inserted via the free-hand technique with postoperative CT, the authors found that the intraoperative CT lowers the threshold for pedicle screw revision, resulting in a statistically higher rate of screw revision in the thoracic and lumbar spine (p < 0.0001). During their 2.5-year experience with the intraoperative CT, the authors did not find a reduction in rates of reoperation for misplaced pedicle screws.


2001 ◽  
Vol 10 (2) ◽  
pp. 1-5 ◽  
Author(s):  
Kee D. Kim ◽  
J. Patrick Johnson ◽  
Jesse D. Babbitz

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.


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