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

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.

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.


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.


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.


Spine ◽  
1997 ◽  
Vol 22 (22) ◽  
pp. 2668-2671 ◽  
Author(s):  
Jung U. Yoo ◽  
Alexander Ghanayem ◽  
Cheryl Petersilge ◽  
Jonathan Lewin

Neurosurgery ◽  
2011 ◽  
Vol 68 (1) ◽  
pp. 170-178 ◽  
Author(s):  
Scott L. Parker ◽  
Matthew J. McGirt ◽  
S Harrison. Farber ◽  
Anubhav G. Amin ◽  
Anne-Marie. Rick ◽  
...  

Abstract BACKGROUND: Pedicle screws are used to stabilize all 3 columns of the spine, but can be technically demanding to place. Although intraoperative fluoroscopy and stereotactic-guided techniques slightly increase placement accuracy, they are also associated with increased radiation exposure to patient and surgeon as well as increased operative time. OBJECTIVE: To describe and critically evaluate our 7-year institutional experience with placement of pedicle screws in the thoracic and lumbar spine using a free-hand technique. METHODS: We retrospectively reviewed records of all patients undergoing free-hand pedicle screw placement without fluoroscopy in the thoracic or lumbar spine between June 2002 and June 2009. Incidence and extent of cortical breach by misplaced pedicle screw was determined by review of postoperative computed tomography scans. We defined breach as more than 25% of the screw diameter residing outside of the pedicle or vertebral body cortex. RESULTS: A total of 964 patients received 6816 free-hand placed pedicle screws in the thoracic or lumbar spine. Indications for hardware placement were degenerative/deformity disease (51.2%), spondylolisthesis (23.7%), tumor (22.7%), trauma (11.3%), infection (7.6%), and congenital (0.9%). A total of 115 screws (1.7%) were identified as breaching the pedicle in 87 patients (9.0%). Breach occurred more frequently in the thoracic than the lumbar spine (2.5% and 0.9%, respectively; P < .0001) and was more often lateral (61.3%) than medial (32.8%) or superior (2.5%). T4 (4.1%) and T6 (4.0%) experienced the highest breach rate, whereas L5 and S1 had the lowest breach rate. Eight patients (0.8%) underwent revision surgery to correct malpositioned screws. CONCLUSION: Free-hand pedicle screw placement based on external anatomy alone can be performed with acceptable safety and accuracy and allows avoidance of radiation exposure encountered in fluoroscopic techniques. Image-guided assistance may be most valuable when placing screws between T4 and T6, where breach rates are highest.


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.


2015 ◽  
Vol 11 (4) ◽  
pp. 530-536 ◽  
Author(s):  
Joshua M Beckman ◽  
Gisela Murray ◽  
Konrad Bach ◽  
Armen Deukmedjian ◽  
Juan S Uribe

Abstract BACKGROUND Multiple methods for minimally invasive (MIS) thoracic and lumbar pedicle screw placement exist. The guide wire is almost universally used for most insertion techniques; however, its use is not without complication and potentially prolongs surgical procedures. OBJECTIVE To evaluate the safety of percutaneous MIS guide wire-less pedicle screw placement in the thoracic and lumbar spine at a single institution over a 3-year experience. METHODS Forty-one patients who underwent posterior instrumentation with 110 transpedicular MIS thoracic and lumbar screws by a single surgeon from 2011 to 2014 were analyzed. The mean age was 63 years at the time of surgery. Etiological diagnoses were adult spinal deformity, trauma, spondylosis/spondylolisthesis, and other spinal diseases. Pedicle screws were inserted with the use of a guide wire-free technique in which anatomy-specific entry sites and fluoroscopic landmarks were used to guide the surgeon. A square, sharp-tipped pedicle screw was carefully advanced under biplanar fluoroscopic image (anteroposterior and lateral) down the pedicle into the body. No tapping or any type of electromonitoring was performed. An independent spine surgeon using medical records and thoracic/lumbar computed tomography taken during the postoperative period reviewed all patients. RESULTS The number of the screws inserted at each level was as follows: total, 110; thoracic, 30; and lumbar, 80. All screws were evaluated by computed tomography to assess screw position. Seven screws (6.3%) were inserted with moderate cortical perforation, including 3 screws (2.7%) that violated the medial wall. There were no neurological, vascular, or visceral complications with up to 3 years of follow-up. CONCLUSION The percutaneous MIS guide wire-less technique of lumbar and thoracic pedicle screw placement performed using a biplanar fluoroscopic guidance in a stepwise, consistent manner is an accurate, safe, and reproducible method of insertion to treat a variety of spinal disorders.


2021 ◽  
pp. 219256822110184
Author(s):  
Rajiv P. Reddy ◽  
Robert Chang ◽  
Dominic V. Coutinho ◽  
Justin W. Meinert ◽  
Katherine M. Anetakis ◽  
...  

Study Design: Systematic review and meta-analysis. Objectives: Malposition of pedicle screws during instrumentation in the lumbar spine is associated with complications secondary to spinal cord or nerve root injury. Intraoperative triggered electromyographic monitoring (t-EMG) may be used during instrumentation for early detection of malposition. The association between lumbar pedicle screws stimulated at low EMG thresholds and postoperative neurological deficits, however, remains unknown. The purpose of this study is to assess whether a low threshold t-EMG response to lumbar pedicle screw stimulation can serve as a predictive tool for postoperative neurological deficit. Methods: The present study is a meta-analysis of the literature from PubMed, Web of Science, and Embase identifying prospective/retrospective studies with outcomes of patients who underwent lumbar spinal fusion with t-EMG testing. Results: The total study cohort consisted of 2,236 patients and the total postoperative neurological deficit rate was 3.04%. 10.78% of the patients incurred at least 1 pedicle screw that was stimulated below the respective EMG alarm threshold intraoperatively. The incidence of postoperative neurological deficits in patients with a lumbar pedicle screw stimulated below EMG alarm threshold during placement was 13.28%, while only 1.80% in the patients without. The pooled DOR was 10.14. Sensitivity was 49% while specificity was 88%. Conclusions: Electrically activated lumbar pedicle screws resulting in low t-EMG alarm thresholds are highly specific but weakly sensitive for new postoperative neurological deficits. Patients with new postoperative neurological deficits after lumbar spine surgery were 10 times more likely to have had a lumbar pedicle screw stimulated at a low EMG threshold.


2018 ◽  
Vol 24 (4) ◽  
pp. 53-63 ◽  
Author(s):  
D. N. Kokushin ◽  
S. V. Vissarionov ◽  
A. G. Baindurashvili ◽  
A. V. Ovechkina ◽  
M. S. Poznovich

Objective.To evaluate accuracy between pedicle screw placement in vertebral bodies achieved in vivo with freehand techniques versus their placement in vertebrae plastic models achieved in vitro with the use of guide templates, in toddlers and preschool children with congenital kyphoscoliosis of the thoracolumbar transition and lumbar spine amid the vertebral malformation.Material and Methods. The research is based on a retrospective analysis of the results of treatment of 10 patients with congenital kyphoscoliosis of the thoracolumbar transition and lumbar spine amid the vertebral malformation. Age – from 2 years 2 months to 6 years 8 months old (mean 3 years 8 months old), gender – 6 boys, 4 girls. Based on the postoperative multi-slice spiral computed tomography (MSCT) of the spine, the pedicle screws placement accuracy of the correcting multi-support metalwork was evaluated. These patients constituted the 1st research group (in vivo group). The 2nd research group (in vitro group) was formed from 27 vertebrae plastic models with pedicle screws inserted in them with the use of guide templates. The placement accuracy of the installed pedicle support elements was assessed based on the S.D. Gertzbein et al. scale (1990).Results. In the 1st group, there were 52 pedicle screws placed. The screw placement accuracy according to the rate of misplacement, as follows: 53.8% in Grade 0, 25% in Grade I, 11.6% in Grade II, 9.6% in Grade III. The number of screws with the rate of misplacement in Grade 0 + Grade I was 41 (78.8%). In the 2nd group, there were 54 screws placed and slightly larger than the 1st group. The screw placement accuracy according to the rate of misplacement was 94.4% in Grade 0, 1.9% in Grade I, 3.7% in Grade II, respectively. The number of screws with the rate of misplacement in Grade 0 + Grade I was 52 (96.3%).Conclusions.Comparative analysis showed that the number of pedicle screws successfully placed in vertebrae plastic models in children with congenital deformities of the thoracolumbar transition and lumbar spine achieved with the use of guide templates was significantly higher than the number of screws successfully placed with freehand techniques (96.3% versus 80.8%, p = 0.011). The results obtained with method of navigation templates in vitro showed high precision and accuracy of pedicle screw placement which gives the prospect for using this type of navigation in clinical practice in toddlers with congenital scoliosis. 


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.


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