Accuracy of Free-Hand Pedicle Screws in the Thoracic and Lumbar Spine: Analysis of 6816 Consecutive Screws

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 ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Radiation Exposure ◽  
Pedicle Screw ◽  
Pedicle Screws ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
Intraoperative Fluoroscopy ◽  
Thoracic And Lumbar Spine ◽  
Institutional Experience ◽  
Screw Diameter

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.

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
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.

scholarly journals A Novel Augmented-Reality-Based Surgical Navigation System for Spine Surgery in a Hybrid Operating Room: Design, Workflow, and Clinical Applications

2019 ◽  
Vol 18 (5) ◽  
pp. 496-502 ◽  
Author(s):  
Erik Edström ◽  
Gustav Burström ◽  
Rami Nachabe ◽  
Paul Gerdhem ◽  
Adrian Elmi Terander
Keyword(s):  
Augmented Reality ◽  
Radiation Exposure ◽  
Pedicle Screw ◽  
Operating Room ◽  
Wound Closure ◽  
Surgical Navigation ◽  
Pedicle Screws ◽  
Screw Placement ◽  
Hybrid Operating Room ◽  
Pedicle Screw Placement

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.

scholarly journals Evaluation of C2 pedicle screw placement via the freehand technique by neurosurgical trainees

2018 ◽  
Vol 29 (3) ◽  
pp. 235-240 ◽  
Author(s):  
Martin H. Pham ◽  
Joshua Bakhsheshian ◽  
Patrick C. Reid ◽  
Ian A. Buchanan ◽  
Vance L. Fredrickson ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Medical Center ◽  
Pedicle Screws ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
C2 Pedicle Screw ◽  
Canal Diameter ◽  
Screw Length ◽  
Freehand Technique ◽  
Screw Diameter

OBJECTIVEFreehand placement of C2 instrumentation is technically challenging and has a learning curve due the unique anatomy of the region. This study evaluated the accuracy of C2 pedicle screws placed via the freehand technique by neurosurgical resident trainees.METHODSThe authors retrospectively reviewed all patients treated at the LAC+USC Medical Center undergoing C2 pedicle screw placement in which the freehand technique was used over a 1-year period, from June 2016 to June 2017; all procedures were performed by neurosurgical residents. Measurements of C2 were obtained from preoperative CT scans, and breach rates were determined from coronal reconstructions on postoperative scans. Severity of breaches reflected the percentage of screw diameter beyond the cortical edge (I = < 25%; II = 26%–50%; III = 51%–75%; IV = 76%–100%).RESULTSNeurosurgical residents placed 40 C2 pedicle screws in 24 consecutively treated patients. All screws were placed by or under the guidance of Pham, who is a postgraduate year 7 (PGY-7) neurosurgical resident with attending staff privileges, with a PGY-2 to PGY-4 resident assistant. The authors found an average axial pedicle diameter of 5.8 mm, axial angle of 43.1°, sagittal angle of 23.0°, spinal canal diameter of 25.1 mm, and axial transverse foramen diameter of 5.9 mm. There were 17 screws placed by PGY-2 residents, 7 screws placed by PGY-4 residents, and 16 screws placed by the PGY-7 resident. The average screw length was 26.0 mm, with a screw diameter of 3.5 mm or 4.0 mm. There were 7 total breaches (17.5%), of which 4 were superior (10.0%) and 3 were lateral (7.5%). There were no medial breaches. The breaches were classified as grade I in 3 cases (42.9%), II in 3 cases (42.9%), III in 1 case (14.3%), and IV in no cases. There were 3 breaches that occurred via placement by a PGY-2 resident, 3 breaches by a PGY-4 resident, and 1 breach by the PGY-7 resident. There were no clinical sequelae due to these breaches.CONCLUSIONSFreehand placement of C2 pedicle screws can be done safely by neurosurgical residents in early training. When breaches occurred, they tended to be superior in location and related to screw length choice, and no breaches were found to be clinically significant. Controlled exposure to this unique anatomy is especially pertinent in the era of work-hour restrictions.

Pedicle Screw Placement in the Thoracic and Lumbar Spine by the C-arm Guided Navigation and the Free Hand Method: A Technical and Outcome Analysis

2016 ◽  
Vol 3 (3) ◽  
pp. 90-95 ◽  
Author(s):  
Anantha Kishan ◽  
Anantha Gabbita ◽  
DN Varadaraju ◽  
Mohamed M Usman ◽  
Shivalinge G Patil ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Screw Placement ◽  
Outcome Analysis ◽  
Pedicle Screw Placement ◽  
Thoracic And Lumbar Spine

Percutaneous Minimally Invasive (MIS) Guide Wire-less Self-Tapping Pedicle Screw Placement in the Thoracic and Lumbar Spine: Safety and Initial Clinical Experience: Technical Note

2015 ◽  
Vol 11 (4) ◽  
pp. 530-536 ◽  
Author(s):  
Joshua M Beckman ◽  
Gisela Murray ◽  
Konrad Bach ◽  
Armen Deukmedjian ◽  
Juan S Uribe
Keyword(s):  
Computed Tomography ◽  
Lumbar Spine ◽  
Minimally Invasive ◽  
Pedicle Screw ◽  
Guide Wire ◽  
The Body ◽  
Screw Placement ◽  
Spinal Diseases ◽  
Pedicle Screw Placement ◽  
Thoracic And Lumbar Spine

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.

scholarly journals Comparative Analysis of Pedicle Screw Placement in Children with Congenital Scoliosis: Freehand Technique (in vivo) and Guide Templates (in vitro)

2018 ◽  
Vol 24 (4) ◽  
pp. 53-63 ◽  
Author(s):  
D. N. Kokushin ◽  
S. V. Vissarionov ◽  
A. G. Baindurashvili ◽  
A. V. Ovechkina ◽  
M. S. Poznovich
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Pedicle Screws ◽  
Congenital Scoliosis ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
Placement Accuracy ◽  
Thoracolumbar Transition

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. 

scholarly journals Freehand thoracic pedicle screw technique using a uniform entry point and sagittal trajectory for all levels: preliminary clinical experience

2014 ◽  
Vol 21 (5) ◽  
pp. 778-784 ◽  
Author(s):  
Vernard S. Fennell ◽  
Sheri Palejwala ◽  
Jesse Skoch ◽  
David A. Stidd ◽  
Ali A. Baaj
Keyword(s):  
Pedicle Screw ◽  
Pedicle Screws ◽  
Transverse Process ◽  
Pedicle Screw Fixation ◽  
Entry Point ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
Thoracic Pedicle Screw ◽  
Thoracic Pedicle Screws ◽  
Screw Diameter

Object Experience with freehand thoracic pedicle screw placement is well described in the literature. Published techniques rely on various starting points and trajectories for each level or segment of the thoracic spine. Furthermore, few studies provide specific guidance on sagittal and axial trajectories. The goal of this study was to propose a uniform entry point and sagittal trajectory for all thoracic levels during freehand pedicle screw placement and determine the accuracy of this technique. Methods The authors retrospectively reviewed postoperative CT scans of 33 consecutive patients who underwent open, freehand thoracic pedicle-screw fixation using a uniform entry point and sagittal trajectory for all levels. The same entry point for each level was defined as a point 3 mm caudal to the junction of the transverse process and the lateral margin of the superior articulating process, and the sagittal trajectory was always orthogonal to the dorsal curvature of the spine at that level. The medial angulation (axial trajectory) was approximately 30° at T-1 and T-2, and 20° from T-3 to T-12. Breach was defined as greater than 25% of the screw diameter residing outside of the pedicle or vertebral body. Results A total of 219 thoracic pedicle screws were placed with a 96% accuracy rate. There were no medial breaches and 9 minor lateral breaches (4.1%). None of the screws had to be repositioned postoperatively, and there were no neurovascular complications associated with the breaches. Conclusions It is feasible to place freehand thoracic pedicle screws using a uniform entry point and sagittal trajectory for all levels. The entry point does not have to be adjusted for each level as reported in existing studies, although this technique was not tested in severe scoliotic spines. While other techniques are effective and widely used, this particular method provides more specific parameters and may be easier to learn, teach, and adopt.

Safety and efficacy of pedicle screw placement using intraoperative computed tomography: consecutive series of 1148 pedicle screws

2014 ◽  
Vol 21 (3) ◽  
pp. 320-328 ◽  
Author(s):  
Mohamad Bydon ◽  
Risheng Xu ◽  
Anubhav G. Amin ◽  
Mohamed Macki ◽  
Paul Kaloostian ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Spinal Instrumentation ◽  
Pedicle Screws ◽  
Ct Scanning ◽  
Screw Placement ◽  
Cervical Region ◽  
Consecutive Series ◽  
Pedicle Screw Placement ◽  
Intraoperative Ct

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.

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