Accuracy and technical limits of percutaneous pedicle screw placement in the thoracolumbar spine

Author(s):  
Yann Philippe Charles ◽  
Yves Ntilikina ◽  
Arnaud Collinet ◽  
Sébastien Schuller ◽  
Julien Garnon ◽  
...  
Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Guang-Ting Cong ◽  
Avani Vaishnav ◽  
Joseph Barbera ◽  
Hiroshi Kumagai ◽  
James Dowdell ◽  
...  

Abstract INTRODUCTION Posterior spinal instrumentation for fusion using intraoperative computed tomography (CT) navigation is gaining traction as an alternative to the conventional two-dimensional fluoroscopic-guided approach to percutaneous pedicle screw placement. However, few studies to date have directly compared outcomes of these 2 minimally invasive instrumentation methods. METHODS A consecutive cohort of patients undergoing primary percutaneous posterior lumbar spine instrumentation for spine fusion was retrospectively reviewed. Revision surgeries or cases converted to open were excluded. Accuracy of screw placement was assessed using a postoperative CT scan with blinding to the surgical methods used. The Gertzbein-Robbins classification was used to grade cortical breach: Grade 0 (<0 mm cortical breach), Grade I (<2 mm), Grade II (2-4 mm), Grade III (4-6 mm), and Grade IV (>6 mm). RESULTS CT navigation was found to significantly improve accuracy of screw placement (P < .022). There was significantly more facet violation of the unfused level in the fluoroscopy group vs the CT group (9% vs 0.5%; P < .0001). There was also a higher proportion of poor screw placement in the fluoroscopy group (10.1% vs 3.6%). No statistical difference was found in the rate of tip breach, inferomedial breach, or lateral breach. Regression analysis showed that fluoroscopy had twice the odds of incurring poor screw placement as compared to CT navigation. CONCLUSION This radiographic study comparing screw placement in minimally invasive fluoroscopy- vs CT navigation-guided lumbar spine instrumentation provides evidence that CT navigation significantly improves accuracy of screw placement, especially in optimizing the screw trajectory so as to avoid facet violation. Long-term follow-up studies should be performed to ascertain whether this difference can contribute to an improvement in clinical outcomes.


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 5 (1) ◽  
pp. 14
Author(s):  
John B. Pracyk ◽  
Nicole Ferko ◽  
Adrian P. Turner ◽  
Sara N. Root ◽  
Heather Cannon ◽  
...  

Guidewires (Kirschner or “K” wires) are often required during minimally invasive spine surgery to facilitate percutaneous pedicle screw placement. The use of guidewires involves a multi-step process that carries the risk of complications and their associated consequences. To date, the reporting of such information has been limited, and the literature has not been thoroughly evaluated. The objective of this study was to conduct a narrative review and assess the burden associated with guidewire use in spine surgeries. Databases searched included PubMed and Embase between the years of 1988 and 2017. In addition to databases, recent data from relevant trade journals were hand-searched. Inclusion criteria were broad to avoid potential exclusion of relevant publications. In total, 31 articles were included. This review found that the risk of complications associated with guidewire use in spine procedures ranged from 0.4% to 14.8%. Complication types included guidewire fracture, cerebrospinal fluid leakage, post-operative ileus, infection, and other spinal hardware failure (e.g., pedicle screw pull-out). Causes of complications typically included breakage and migration of the guidewire (metal fatigue), inexperience with guidewire use, or lack of tactile or visual feedback. Specific surgery types or patient populations may be more susceptible to guidewire-related complications (e.g., L5-S1 level operations). Complications associated with guidewire use may also lead to healthcare resource utilization, including additional operating time, radiation exposure, and re-operations. Solutions to help minimize the risk of such complications and associated consequences are required.


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.


2011 ◽  
Vol 24 (4) ◽  
pp. 264-267 ◽  
Author(s):  
Thomas E. Mroz ◽  
Kalil G. Abdullah ◽  
Michael P. Steinmetz ◽  
Eric O. Klineberg ◽  
Isador H. Lieberman

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