Pedicle screw insertion in the thoracolumbar spine: comparison of 4 guidance techniques in the intact cadaveric spine

2011 ◽  
Vol 14 (5) ◽  
pp. 664-669 ◽  
Author(s):  
Husam Alhabib ◽  
Andrew Nataraj ◽  
Mohammed Khashab ◽  
James Mahood ◽  
Frank Kortbeek ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Thoracolumbar Spine ◽  
Pedicle Screws ◽  
Pedicle Screw Fixation ◽  
Anatomical Landmarks ◽  
Imaging Data ◽  
Anatomical Dissection ◽  
Screw Insertion ◽  
Fluoroscopic Navigation ◽  
Screw Position

Object Pedicle screw fixation is a mainstay of thoracolumbar stabilization. Screw insertion using anatomical landmarks and fluoroscopy is common but can be technically challenging and generally involves substantial exposure to ionizing radiation. Computerized navigation has been reported to improve accuracy but is expensive and complex. The authors undertook this study to evaluate these 3 methods in comparison with a fourth technique using standard cervical distractor screws to mark the entry point and trajectory. Methods Four cadaveric human spines were used for this study. After an initial CT scan, 34 pedicle screws were inserted in each intact spine from T-1 to L-5 using the following 4 screw insertion guidance techniques (1 technique per specimen): use of anatomical landmarks, use of cervical distractor screws and spot fluoroscopy, fluoroscopy-based navigation, and fluoroscopy- and CT-based navigation (using merged imaging data). Postprocedural CT and anatomical dissection were then performed to evaluate screw position for site and degree of breach. Results The cervical distractor screw method had a breach rate of 5.9% versus 29.4%, 32.4%, and 20.6% for use of anatomical landmarks, fluoroscopic navigation, and fluoroscopic-CT navigation, respectively (p < 0.05). There is also a significant association between degree of medial and distal breach and the method of screw insertion (p < 0.05). Conclusions Cervical distractor screws as pedicle markers offer favorable insertion accuracy and reduction of radiation exposure compared with the other 3 methods used in clinical practice.

scholarly journals Is Freehand Technique of Pedicle Screw Insertion in Thoracolumbar Spine Safe and Accurate? Assessment of 250 Screws

2019 ◽  
Vol 10 (02) ◽  
pp. 256-260 ◽  
Author(s):  
N. Vijayeswaran ◽  
Raju Venkatesh ◽  
G. Murugesan ◽  
S. Balamurugan ◽  
K. Indunesh ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Screw Fixation ◽  
Thoracolumbar Spine ◽  
Pedicle Screws ◽  
Pedicle Screw Fixation ◽  
Screw Insertion ◽  
Freehand Technique ◽  
Close Observation ◽  
Screw Penetration ◽  
Surgical Duration

ABSTRACT Background: Pedicle screw fixation is one of the widely used procedures for instrumentation and stabilization of the thoracic and lumbar spine. It has the advantage of stabilizing all the three columns in single approach. Various assistive techniques are available to place the pedicle screws more accurately but at the expense of increased exposure to radiation, prolonged surgical duration, and cost. Objective: The objective of this study is to determine the accuracy and safety of pedicle screw fixation in the thoracolumbar spine using freehand surgical technique. Materials and Methods: We evaluated all patients who underwent pedicle screw fixation of the thoracolumbar spine for various ailments at our institute from January 2016 to December 2017 with postoperative computed tomography scan for placement accuracy. We used Gertzbein classification to grade pedicle breaches. Screw penetration more than 4 mm was taken as critical and those less than that were classified as noncritical. Results: A total of 256 screws inserted in T1–L5 vertebrae were included from 40 consecutive patients. Six screws were excluded according to selection criteria. The mean age was 39 years. Trauma (36 patients) was the common reason for which the pedicle screw fixation was done followed by degenerative disease (2 patients) and tumour (2 patients). A total of ten pedicle screw breaches (4%) were identified in eight patients. Among these, three critical breaches (1.2%) were occurred in two patients which required revision. The remaining seven breaches were noncritical and kept under close observation and follow-up. Conclusion: Pedicle screw had become the workhorse of posterior stabilization of the spine. Based on external anatomy and landmarks alone, freehand technique for pedicle screw fixation can be performed with acceptable safety and accuracy avoiding cumulative radiation exposure and prolonged operative time.

Accuracy and safety of pedicle screw fixation in thoracic spine trauma

2006 ◽  
Vol 5 (6) ◽  
pp. 520-526 ◽  
Author(s):  
Charles G. Fisher ◽  
Vic Sahajpal ◽  
Ory Keynan ◽  
Michael Boyd ◽  
Douglas Graeb ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Thoracic Spine ◽  
Pedicle Screws ◽  
Pedicle Screw Fixation ◽  
Spine Fractures ◽  
Chi Square ◽  
Clinical Safety ◽  
Thoracic Spine Fractures ◽  
Screw Position ◽  
Pedicle Wall

Object The authors evaluated the accuracy of placement and safety of pedicle screws in the treatment of unstable thoracic spine fractures. Methods Patients with unstable fractures between T-1 and T-10, which had been treated with pedicle screw (PS) placement by one of five spine surgeons at a referral center were included in a prospective cohort study. Postoperative computed tomography scans were obtained using 3-mm axial cuts with sagittal reconstructions. Three independent reviewers (C.B., V.S., and D.G.) assessed PS position using a validated grading scale. Comparison of failure rates among cases grouped by selected baseline variables were performed using Pearson chi-square tests. Independent peri- and postoperative surveillance for local and general complications was performed to assess safety. Twenty-three patients with unstable thoracic fractures treated with 201 thoracic PSs were analyzed. Only PSs located between T-1 and T-12 were studied, with the majority of screws placed between T-5 and T-10. Of the 201 thoracic PSs, 133 (66.2%) were fully contained within the pedicle wall. The remaining 68 screws (33.8%) violated the pedicle wall. Of these, 36 (52.9%) were lateral, 27 (39.7%) were medial, and five (7.4%) were anterior perforations. No superior, inferior, anteromedial, or anterolateral perforations were found. When local anatomy and the clinical safety of screws were considered, 98.5% (198 of 201) of the screws were probably in an acceptable position. No baseline variables influenced the incidence of perforations. There were no adverse neurological, vascular, or visceral injuries detected intraoperatively or postoperatively. Conclusions In the vast majority of cases, PSs can be placed in an acceptable and safe position by fellowship-trained spine surgeons when treating unstable thoracic spine fractures. However, an unacceptable screw position can occur.

scholarly journals Accuracy of robot-guided versus freehand fluoroscopy-assisted pedicle screw insertion in thoracolumbar spinal surgery

2017 ◽  
Vol 42 (5) ◽  
pp. E14 ◽  
Author(s):  
Granit Molliqaj ◽  
Bawarjan Schatlo ◽  
Awad Alaid ◽  
Volodymyr Solomiichuk ◽  
Veit Rohde ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Spinal Instrumentation ◽  
Pedicle Screws ◽  
Screw Placement ◽  
Robotic Assistance ◽  
Anatomical Landmarks ◽  
Pedicle Screw Placement ◽  
Robot Assisted ◽  
Screw Insertion ◽  
Freehand Technique

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.

Evaluation of pedicle screw position on computerized tomography scans

2003 ◽  
Vol 98 (1) ◽  
pp. 104-109
Author(s):  
Jin Sup Yeom ◽  
Moon Sang Chung ◽  
Choon-Ki Lee ◽  
Yeongho Kim ◽  
Namkug Kim ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Computerized Tomography ◽  
Pedicle Screws ◽  
Ct Scans ◽  
Metal Artifact ◽  
Content Type ◽  
Screw Insertion ◽  
Bone Window ◽  
Screw Position ◽  
Fine Print

✓ The quality of a computerized tomography (CT) scan is significantly reduced by metal artifact caused by a pedicle screw system. The purpose of this study was to develop a method of facilitating the evaluation of pedicle screw position on CT scans obtained after screw insertion. The authors developed an algorithm to process spiral CT scans in a personal computer. This uses a digital image enhancement technique, the curve change-based intensity transformation algorithm. This method can generate a clear image of the screw outlines while reducing metal artifact. The resulting images are displayed in arbitrary planes as well as in axial, coronal, and sagittal planes, to support better the evaluation of pedicle screw position. The algorithm was tested using CT scans obtained in 37 patients in whom 186 pedicle screws had been placed. There were five types of screw systems, all of which were made of titanium alloys. In all cases algorithm-based determination of screw position became more convenient and more accurate than when using the conventional bone window setting. In addition, it provided better soft-tissue visualization than the bone window. The software, by displaying clear outlines of screws and decreasing metal artifact, as well as by reconstructing the images in arbitrary planes, was more helpful in identifying the position of pedicle screws than the conventional bone window setting.

scholarly journals Anatomic Study of Individualized and Improved Pedicle Screw Implantation in the Lower Cervical Spine

2015 ◽  
Vol 100 (2) ◽  
pp. 328-333 ◽  
Author(s):  
Yuan Liu ◽  
Bin Zhang ◽  
Min Dai ◽  
Han-chu Xiong ◽  
Song Gao ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Pedicle Screw ◽  
Pedicle Screws ◽  
Pedicle Screw Fixation ◽  
Lower Cervical Spine ◽  
Optimal Position ◽  
Screw Position ◽  
Cervical Pedicle ◽  
Picture Archiving And Communication ◽  
Ct Classification

The objective of this study was to explore a safe, reliable, and effective method for pedicle screw implantation in the lower cervical spine. Recently, a number of studies have shown that cervical pedicle screw fixation is better than roadside steel plate after cervical screw internal fixation within the scope of its indications. However, the difficulty of the former surgery technology is relatively higher and it is much easier to cause many complications. Therefore, domestic and foreign scholars have been positively exploring safer, easier operations and cheaper methods of pedicle screw implantation in the lower cervical spine. The lower cervical spine areas (C3–C7) of 7 adult cadavers were carried out with computed tomography (CT) scans of 1-mm slices. The entry point, angle, and length of the screws were determined by the measurement of CT images in a picture archiving and communication system. The pedicle screws were implanted with the technique of improved Abumi pedicle screw placement in the lab. The accuracy of the screws was evaluated by the Andrew CT classification criteria of pedicle screw position and gross observation after the experiment. A total of 66 screws were implanted in the lower cervical spine, and 90.9% of the screws inserted were found to be in an optimal position. The method of individualized and improved pedicle screw implantation in the lower cervical spine is relatively safe and reliable, which can be considered to be used in the clinic.

scholarly journals Percutaneous “K-wireless” pedicle screw fixation technique: an evaluation of the initial experience of 100 screws with assessment of accuracy, radiation exposure, and procedure time

2015 ◽  
Vol 22 (4) ◽  
pp. 422-431 ◽  
Author(s):  
Steven M. Spitz ◽  
Faheem A. Sandhu ◽  
Jean-Marc Voyadzis
Keyword(s):  
Pedicle Screw ◽  
Pedicle Screws ◽  
Pedicle Screw Fixation ◽  
Screw Placement ◽  
Lumbosacral Spine ◽  
Visceral Injury ◽  
Screw Insertion ◽  
Pull Out ◽  
Percutaneous Pedicle Screw ◽  
K Wires

OBJECT Percutaneous pedicle screws are used to provide rigid internal fixation in minimally invasive spinal procedures and generally require the use of Kirchner wires (or K-wires) as a guide for screw insertion. K-wires can bend, break, advance, or pull out during the steps of pedicle preparation and screw insertion. This can lead to increased fluoroscopic and surgical times and potentially cause neurological, vascular, or visceral injury. The authors present their experience with a novel “K-wireless” percutaneous pedicle screw system that eliminates the inherent risks of K-wire use. METHODS A total of 100 screws were placed in 28 patients using the K-wireless percutaneous screw system. Postoperative dedicated spinal CT scans were performed in 25 patients to assess the accuracy of screw placement. Screw placement was graded A through D by 2 independent radiologists: A = within pedicle, B = breach < 2 mm, C = breach of 2–4 mm, and D = breach > 4 mm. Screw insertion and fluoroscopy times were also recorded in each case. Clinical complications associated with screw insertion were documented. RESULTS A total of 100 K-wireless percutaneous pedicle screws were placed into the lumbosacral spine in 28 patients. Postoperative CT was performed in 25 patients, thus the placement of only 90 screws was assessed. Eighty-seven screws were placed within the pedicle confines (Grade A), and 3 violated the pedicle (2 Grade B [1 lateral, 1 medial] and 1 Grade D [medial]) for an overall accuracy rate of 96.7%. One patient required reoperation for screw repositioning due to a postoperative L-5 radiculopathy secondary to a Grade D medial breach at L-5. This patient experienced improvement of the radiculopathy after reoperation. Average screw insertion and fluoroscopy times were 6.92 minutes and 22.7 seconds per screw, respectively. CONCLUSIONS The results of this study demonstrate that the placement of K-wireless percutaneous pedicle screws is technically feasible and can be performed accurately and safely with short procedure and fluoroscopy times.

scholarly journals A cadaveric precision and accuracy analysis of augmented reality–mediated percutaneous pedicle implant insertion

2020 ◽  
pp. 1-9 ◽  
Author(s):  
Camilo A. Molina ◽  
Frank M. Phillips ◽  
Matthew W. Colman ◽  
Wilson Z. Ray ◽  
Majid Khan ◽  
...  
Keyword(s):  
Augmented Reality ◽  
Pedicle Screw ◽  
Pedicle Screws ◽  
Angular Deviation ◽  
Screw Insertion ◽  
Head Mounted Display ◽  
Percutaneous Pedicle Screw ◽  
Field Of Vision ◽  
Clinical Accuracy ◽  
Screw Position

OBJECTIVEAugmented reality–mediated spine surgery (ARMSS) is a minimally invasive novel technology that has the potential to increase the efficiency, accuracy, and safety of conventional percutaneous pedicle screw insertion methods. Visual 3D spinal anatomical and 2D navigation images are directly projected onto the operator’s retina and superimposed over the surgical field, eliminating field of vision and attention shift to a remote display. The objective of this cadaveric study was to assess the accuracy and precision of percutaneous ARMSS pedicle implant insertion.METHODSInstrumentation was placed in 5 cadaveric torsos via ARMSS with the xvision augmented reality head-mounted display (AR-HMD) platform at levels ranging from T5 to S1 for a total of 113 total implants (93 pedicle screws and 20 Jamshidi needles). Postprocedural CT scans were graded by two independent neuroradiologists using the Gertzbein-Robbins scale (grades A–E) for clinical accuracy. Technical precision was calculated using superimposition analysis employing the Medical Image Interaction Toolkit to yield angular trajectory (°) and linear screw tip (mm) deviation from the virtual pedicle screw position compared with the actual pedicle screw position on postprocedural CT imaging.RESULTSThe overall implant insertion clinical accuracy achieved was 99.1%. Lumbosacral and thoracic clinical accuracies were 100% and 98.2%, respectively. Specifically, among all implants inserted, 112 were noted to be Gertzbein-Robbins grade A or B (99.12%), with only 1 medial Gertzbein-Robbins grade C breach (> 2-mm pedicle breach) in a thoracic pedicle at T9. Precision analysis of the inserted pedicle screws yielded a mean screw tip linear deviation of 1.98 mm (99% CI 1.74–2.22 mm) and a mean angular error of 1.29° (99% CI 1.11°–1.46°) from the projected trajectory. These data compare favorably with data from existing navigation platforms and regulatory precision requirements mandating that linear and angular deviation be less than 3 mm (p < 0.01) and 3° (p < 0.01), respectively.CONCLUSIONSPercutaneous ARMSS pedicle implant insertion is a technically feasible, accurate, and highly precise method.

Augmented reality–assisted pedicle screw insertion: a cadaveric proof-of-concept study

2019 ◽  
Vol 31 (1) ◽  
pp. 139-146 ◽  
Author(s):  
Camilo A. Molina ◽  
Nicholas Theodore ◽  
A. Karim Ahmed ◽  
Erick M. Westbroek ◽  
Yigal Mirovsky ◽  
...  
Keyword(s):  
Augmented Reality ◽  
Pedicle Screw ◽  
User Experience ◽  
Pedicle Screws ◽  
Screw Insertion ◽  
Pedicle Screw Insertion ◽  
Insertion Method ◽  
Comparative Accuracy ◽  
Placement Accuracy ◽  
Surgical Field

OBJECTIVEAugmented reality (AR) is a novel technology that has the potential to increase the technical feasibility, accuracy, and safety of conventional manual and robotic computer-navigated pedicle insertion methods. Visual data are directly projected to the operator’s retina and overlaid onto the surgical field, thereby removing the requirement to shift attention to a remote display. The objective of this study was to assess the comparative accuracy of AR-assisted pedicle screw insertion in comparison to conventional pedicle screw insertion methods.METHODSFive cadaveric male torsos were instrumented bilaterally from T6 to L5 for a total of 120 inserted pedicle screws. Postprocedural CT scans were obtained, and screw insertion accuracy was graded by 2 independent neuroradiologists using both the Gertzbein scale (GS) and a combination of that scale and the Heary classification, referred to in this paper as the Heary-Gertzbein scale (HGS). Non-inferiority analysis was performed, comparing the accuracy to freehand, manual computer-navigated, and robotics-assisted computer-navigated insertion accuracy rates reported in the literature. User experience analysis was conducted via a user experience questionnaire filled out by operators after the procedures.RESULTSThe overall screw placement accuracy achieved with the AR system was 96.7% based on the HGS and 94.6% based on the GS. Insertion accuracy was non-inferior to accuracy reported for manual computer-navigated pedicle insertion based on both the GS and the HGS scores. When compared to accuracy reported for robotics-assisted computer-navigated insertion, accuracy achieved with the AR system was found to be non-inferior when assessed with the GS, but superior when assessed with the HGS. Last, accuracy results achieved with the AR system were found to be superior to results obtained with freehand insertion based on both the HGS and the GS scores. Accuracy results were not found to be inferior in any comparison. User experience analysis yielded “excellent” usability classification.CONCLUSIONSAR-assisted pedicle screw insertion is a technically feasible and accurate insertion method.

The accuracy of pedicle screw placement using intraoperative image guidance systems

2014 ◽  
Vol 20 (2) ◽  
pp. 196-203 ◽  
Author(s):  
Alexander Mason ◽  
Renee Paulsen ◽  
Jason M. Babuska ◽  
Sharad Rajpal ◽  
Sigita Burneikiene ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Image Guidance ◽  
Pedicle Screws ◽  
Screw Placement ◽  
Data Sets ◽  
Pedicle Screw Placement ◽  
Fluoroscopic Image ◽  
Fluoroscopic Navigation ◽  
Guidance Systems ◽  
Accuracy Rates

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.

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