Accuracy Of Screw Placement Research Articles

Robotic-Assisted and Computer-Assisted Navigation Surgery in the Cervical Spine: Current Experiences, Techniques, and Accuracy

Background: In recent years, the role of robotic-assisted and computer-assisted navigation (RA-CAN) systems has significantly expanded in spine surgery, particularly those performed in the thoracic, lumbar and sacral spine showing higher accuracy in pedicle screw placement and improved surgical efficiency. However, there are few reports on these techniques in the cervical spine. The anatomy of the cervical spine possesses additional challenges such as the close proximity to critical neurovascular structures. Purpose: In this article, we present the existing clinical experience of RA-CAN in the cervical spine and evaluate technical considerations. Cervical spine screw fixation and decompression using RA-CAN are reviewed. Results: This analysis covers various aspects such as techniques, accuracy, and the types of procedures reported in the literature. Recent reports include surgical procedures such as anterior cervical diskectomy and fusion’s, odontoid fracture fixation, C1 lateral mass, C2 pedicle, translaminar, subaxial spine lateral mass, and mid-cervical spine pedicle screw fixation. There is potential for enormous clinical benefit to navigated decompression in cervical CAN procedures also. Future opportunities include further improvements in imaging co-localization, pre-surgical planning software, and mechanization of surgical procedures for instrumentation and decompression. Conclusion: The growth of RA-CAN in spinal surgery has shown significant potential in its application in the cervical spine for fusion procedures as well as decompression. By understanding the potential limitations and techniques reported from early experiences, previous techniques can be improved and provide further benefits for accuracy and less invasive surgery.

Effect of a Percutaneous Screw Guide on Screw Placement for Posterior Talar Fractures.

This study aimed to evaluate the hypothesis that the utilization of percutaneous screw guides enhances the precision of screw placement in the surgical fixation of talar fractures. Computed tomography (CT) scans of ankle joints were obtained from 40 healthy adults and 10 cadaveric specimens between April 2019 and August 2020 at Ningbo No. 6 Hospital. The acquired CT data were imported into Materialise Interactive Medical Image Control System (MIMICS) software for processing. Three-dimensional (3D) digital models of the ankle joints were reconstructed, and relevant anatomical parameters were measured. A percutaneous screw guide (PSG) was designed and fabricated to facilitate accurate screw placement in the posterior talar process. Ten eligible cadaveric ankle joints were selected for further analysis and their 3D models were reconstructed using the MIMICS software. Screw trajectory parameters were then measured and analyzed based on these cadaveric models, forming the model group for comparative analyses. Ten cadaveric specimens were utilized in this study, equally divided into two groups: a guider group (n = 5) and a free-hand group (n = 5). In the guider group, talar posterior process screws were inserted using percutaneous screw guidance. In the free-hand group, screws were inserted into the talar posterior process without guidance. Post-operative CT scans were performed on all specimens. The following parameters were quantitatively compared between the two groups: screw trajectories, entry point distances in specimens with preselected screws, entry point distance trajectories in the 3D model, operation time, frequency of fluoroscopic imaging, and number of drilling attempts. Following the generation of the 3D models from 10 cadavers, a virtual screw was digitally inserted into each model. In the model group, the preselected screw trajectory was oriented towards the medial aspect of the talar neck base, with a cephalad inclination angle (CIA) of 3.1° ± 1.5° in the transverse~plane and a medial diverge angle (MDA) of 12.0° ± 1.4° in the coronal plane. The CIA and MDA of the screw trajectory in the guider group were 2.1° ± 1.7° and 11.2° ± 1.6°, respectively, whereas the CIA and MDA in the free-hand group were 6.0° ± 2.2° and 18.8° ± 1.6°, respectively. Statistical analysis revealed significant differences in both CIA and MDA between the two groups (p < 0.05). Furthermore, the guider group yielded superior outcomes in terms of entry point distance, operation time, fluoroscopic exposure time, and number of drilling attempts compared to the free-hand group (p < 0.05). Percutaneous screw guidance can improve the accuracy and safety of the posterior process of the talar screws, which can be feasible for percutaneous fixation. Further studies are required to confirm the efficacy and clinical outcomes of percutaneous screw guidance.

Case series: O-arm navigation assisted by the Wiltse approach improves the accuracy of pedicle screw placement in ankylosing spondylitis combined with thoracolumbar fractures

Here we assessed the accuracy of O-arm navigation assisted by Wiltse approach to improve based pedicle screw insertion in ankylosing spondylitis combined with thoracolumbar fractures. We then compared it with the freehand pedicle screw insertion technique. The study sample included 32 patients with ankylosing spondylitis combined with thoracolumbar fractures. Pedicle screw reduction and internal fixation was performed under an O-arm navigation system assisted by a Wiltse approach-combined osteotomy (“navigation group,” n = 17) and posterior pedicle screw reduction and internal fixation was performed using freehand technique combined osteotomy (“freehand group,” n = 15). We then compared the operation time and bleeding volume between the 2 groups. The visual analog scale (VAS) and Oswestry disability index (ODI) were then used to evaluate the clinical efficacy and the kyphosis Cobb angle was used to evaluate the radiological efficacy before operation, 3 days after operation and after the last follow-up. All complications were noted when detected. Finally, classification of screw positions as proposed by Neo et al was used to evaluate the relationship of the position between the screw, the bone cortex, and the incidence of screw penetration. All patients were followed up for 18 to 36 months (i.e., 24.2 ± 3.5 months). The operation time and intraoperative bleeding volume of the navigation group were significantly shorter (lower) than those of the freehand group (P &lt; .05). In addition, Both groups showed significantly decreased VAS, ODI, and Cobb angle 3 days after the operation and at the last follow-up when compared to values recorded pre-operation. However, we found no significant difference in VAS, ODI, and Cobb angle between the 2 groups (P &gt; .05). We identified no complications (e.g., infection, VTE/PE, or nerve injury). Moreover, the pedicle screw placement position of the navigation group was better than that of the freehand group (P &lt; .05), and the screw cortical penetration rate was lower than the freehand group (P &lt; .05). During the process of posterior pedicle screw placement, O-arm navigation assisted by the Wiltse approach can significantly reduce operation time, minimize the amount of bleeding volume, and enhance the accuracy of pedicle screw implantation.

Accuracy and risk factors of Magerl screw placement in robot-assisted atlantoaxial surgery: A case series study.

To assess the accuracy of robot-assisted Magerl screw placement and explore the factors affecting the accuracy. A retrospective analysis of patients who underwent robot-assisted Magerl screw placement was performed. The accuracy of Magerl screw placement was evaluated according to the Gertzbein and Robbins scale. 47 Magerl screws were placed in 24 consecutive patients. 32 Magerl screws were narrower than the C2 isthmus height and 26 of them were grade A. 15 Magerl screws were wider than the C2 isthmus height and all of them were grade B. Temporary fixation after decompression and a smaller difference between the C2 isthmus height and screw diameter were associated with a higher probability of cortical breach. The accuracy of robot-assisted Magerl screw placement was excellent. Temporary fixation after decompression and a smaller difference between the C2 isthmus height and screw diameter increased the risk of cortical breach.

Analysis of the Screw Accuracy and Postoperative Efficacy of Screw Placement in Single Position and Bipedal Position in Robot-Assisted Oblique Lumbar Interbody Fusion: Preliminary Results of Mazor X Stealth Usage.

Traditional manual OLIF combined with pedicle screw implantation has many problems of manual percutaneous screw implantation, such as high difficulty of screw placement, many fluoroscopies, long operation time, and many adjustments, resulting in greater trauma. The robot can perform various types of screw placement in the lateral recumbent position, which allows OLIF combined with posterior screw placement surgery to be completed in a single position. To compare the screw accuracy and initial postoperative results of oblique anterior lumbar fusion with robot-assisted screw placement in the lateral position and screw placement in the prone position for the treatment of lumbar spondylolisthesis. From May to June 2022, 45 patients with single-segment lumbar spondylolisthesis underwent Mazor X-assisted oblique lumbar fusion in one position and Renaissance-assisted surgery in two different positions, and screw accuracy was assessed on computed tomography scans according to a modified Gertzbein-Robbins classification. Patients were divided into a single position group and a bipedal position group (the lateral position for complete oblique lumbar fusion and then changed to the prone position for posterior screw placement), and the perioperative parameters, including operative time, number of fluoroscopies, and operative complications, were recorded separately. The results of the clinical indicators, such as the visual analog scale (VAS) for back and leg pain and the Oswestry Disability Index (ODI) score, were obtained. There were no significant differences in the patients' demographic data between the two groups. The single position group had a shorter operative time and fewer fluoroscopies than the bipedal position group; the single position group had a higher percentage of screw accuracy at the A level than the bipedal position group, but there was no statistically significant difference between the two groups at the acceptable level (A + B) (p > 0.05). The single-position group had better outcomes at the 1-week postoperative follow-up back pain VAS scores (p < 0.05). There was no statistically significant difference in the postoperative leg pain VAS scores or the ODI scores when compared to the control group. Robot-assisted lateral position oblique lumbar interbody fusion with pedicle screw placement has the same accuracy as prone positioning. Single position surgery can significantly shorten the operation time and reduce the fluoroscopy. There was no significant difference in the long-term efficacy between the two groups.

Mazor X Robot-Assisted Pedicle Screw Placement: A Case Series

Pedicle screw placement is a well-established procedure in spine surgeries, and the utilization of robots in spinal surgery has been on the rise. This study aims to investigate the accuracy and screw placement time associated with the use of Mazor X robots in robotic-assisted pedicle screw placement. A retrospective case study was conducted on 12 patients with lumbar spine disease who underwent Mazor X robot-assisted surgery. Screw placement accuracy was assessed using the Gertzbein-Robinson classification. Additionally, total screw placement time and fluoroscopy time were documented for analysis. A total of 60 screws were placed in the 12 patients who received robotic-assisted pedicle screw placement. Of these screws, 98.3% were found to be within the safe zone. As the cases progressed, there was a noticeable decrease in total screw placement time and fluoroscopy time. Our findings suggest that Mazor X robotic-assisted spine surgery boasts high accuracy rates and demonstrates a decreasing trend in screw placement time and fluoroscopy time. To the best of our knowledge, our institution is the first in China to employ the Mazor X robot for pedicle screw placement surgeries and to document its associated characteristics.

Robot-assisted versus fluoroscopy-guided pedicle screw fixation of thoracolumbar compression fractures.

The aim of this study is to compare the clinical outcomes and accuracy of robot-assisted (RA) versus fluoroscopy-guided (FG) pedicle screw fixation of thoracolumbar compression fractures. We retrospectively enrolled 85 patients with surgically treated thoracolumbar compression fractures in our study (RA group, 45 patients; FG group, 40 patients). We analyzed the accuracy of pedicle screw placement by using the Gertzbein-Robbins classification, and calculated the one-time success rate (i.e., the rate of screws successfully inserted in the first attempt). We also evaluated volume of blood loss, operative time, visual analogue scale scores for pain, Cobb angle, and postoperative complications. The rates of grade A screw placement (96% vs 68.5%; P < .005), clinically acceptable screw placement (98.2% vs 86%; P < .005), and the one-time success rate (97.3% vs 82.5%; P < .005) were all significantly higher in the RA group than in the FG group. No differences were observed in sex, age, body mass index, volume of blood loss, operative time, visual analogue scale scores, Cobb angle, and postoperative complications between the 2 groups. Compared to FG surgery, RA surgery yielded greater accuracy and one-time success rates of pedicle screw fixation of thoracolumbar compression fractures, with comparable clinical outcomes.

The cutting-edge developments and future prospects of enabling technologies in spinal surgery clinical treatments

The technology in spinal surgery clinical treatment is undergoing revolutionary changes in recent years. Artificial intelligence shows promise in enhancing diagnosis, personalizing treatment, and predicting outcomes. Robotic surgery improves safety and precision but its cost-effectiveness limits widespread use. Augmented reality can enhance screw placement accuracy and efficiency, yet requires refinement in precision and user interaction. Three-dimensional printing, through personalized guides and implants, optimizes surgical procedures, though further clinical studies are needed to validate long-term benefits. New implant designs and materials, facilitated by topological optimization, carbon fiber composite polyetheretherketone, present opportunities for creating anatomically and biomechanically congruent spinal implants. This review analyzes the potential and challenges of these advancements in improving surgical accuracy, reducing complications, and meeting individualized treatment needs, aiming to foster the development of more effective and safer spinal surgical techniques. These technologies collectively offer enhanced precision and patient outcomes, signifying a transformative shift in spinal healthcare.

Effects of Augmented Reality on Thoracolumbar Pedicle Screw Instrumentation Across Different Levels of Surgical Experience

Augmented reality (AR) is an emerging technology that may accelerate skill acquisition and improve accuracy of thoracolumbar pedicle screw placements. We aimed to quantify the relative assistance of AR compared with freehand (FH) pedicle screw accuracy across different surgical experience levels. A spine fellowship-trained and board-certified attending neurosurgeon, postgraduate year 4 neurosurgery resident, and second-year medical student placed 32 FH and 32 AR-assisted thoracolumbar pedicle screws in 3 cadavers. A cableless, voice-activated AR system was paired with a headset. Accuracy was assessed using χ2 analysis and the Gertzbein-Robbins scale. Angular error, distance error, and time per pedicle screw were collected and compared. The attending neurosurgeon had 91.6% (11/12) clinically acceptable (Gertzbein-Robbins scale A or B) insertion in both FH and AR groups; the resident neurosurgeon had 100% (9/9) FH and AR in both cases; the medical student had 72.3% (8/11) FH accuracy and 81.8% (9/11) AR accuracy. The medical student displayed significantly lower ideal (Gertzbein-Robbins scale A) FH accuracy compared with the resident neurosurgeon (P= 0.017) and attending neurosurgeon (P= 0.005), but no difference when using AR. FH screw placement was faster by both the attending neurosurgeon (median 46 seconds vs. 94.5 seconds, P= 0.0047) and the neurosurgery resident neurosurgeon (median 144 seconds vs. 140 seconds, P= 0.05). Total clinically acceptable AR and FH accuracy was 90.6% (29/32) and 87.5% (28/32), respectively (P= 0.69). AR screw placement allowed an inexperienced medical student to double their accuracy in 1 training session. With subsequent iterations, this promising technology could serve as an important tool for surgical training.

Specifying the Starting Point for S1 Iliosacral Screw Placement in the Dysmorphic Sacrum.

Sacral dysmorphism is not uncommon and complicates S1 iliosacral screw placement partially because of the difficulty of determining the starting point accurately on the sacral lateral view. We propose a method of specifying the starting point. The starting point for the S1 iliosacral screw into the dysmorphic sacrum was specifically set at a point where the ossification of the S1/S2 intervertebral disc (OSID) intersected the posterior vertebral cortical line (PVCL) on the sacral lateral view, followed by guidewire manipulation and screw placement on the pelvic outlet and inlet views. Computer-simulated virtual surgical procedures based on pelvic computed tomography (CT) data on 95 dysmorphic sacra were performed to determine whether the starting point was below the iliac cortical density (ICD) and in the S1 oblique osseous corridor and to evaluate the accuracy of screw placement (with 1 screw being used, in the left hemipelvis). Surgical procedures on 17 patients were performed to verify the visibility of the OSID and PVCL, to check the location of the starting point relative to the ICD, and to validate the screw placement safety as demonstrated with postoperative CT scans. In the virtual surgical procedures, the starting point was consistently below the ICD and in the oblique osseous corridor in all patients and all screws were Grade 1. In the clinical surgical procedures, the OSID and PVCL were consistently visible and the starting point was always below the ICD in all patients; overall, 21 S1 iliosacral screws were placed in these 17 patients without malpositioning or iatrogenic injury. On the lateral view of the dysmorphic sacrum, the OSID and PVCL are visible and intersect at a point that is consistently below the ICD and in the oblique osseous corridor, and thus they can be used to identify the starting point. Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Unobstructed orthopaedic surgical robot assisted percutaneous iliosacral screw fixation of sacral brittle fractures.

Pelvic fractures mostly result from high-energy injuries in life; the longitudinal fracture of the sacrum is the most common type of sacrum fracture. This study was designed to evaluate the accuracy, safety, and efficacy of percutaneous sacroiliac joint screw placement in the treatment of longitudinal sacrum fractures with the assistance of unobstructed orthopaedic surgery robots. According to different surgical methods, 32 patients were divided into robot group and free hand group, with 16 patients in each group. The operation time, intra-operative blood loss, intra-operative fluoroscopy times, screw placement angle deviation were collected. There were statistically significant differences in terms of angle deviation of screw placement (1.96 ± 0.75° vs. 2.87 ± 1.03°; p = 0.0145), deviation of the guide needle (1.92 ± 0.93 mm vs. 2.91 ± 1.22 mm; p = 0.0209), intra-operative fluoroscopy time (7.25 ± 1.72 s vs. 20.93 ± 5.64 s; p = 0.0000), insertion time of each sacroiliac joint screw (14.72 ± 2.66 min vs. 29.21 ± 5.18 min; p = 0.0000). There was no statistically significant difference in terms of blood loss (100.21 ± 7.37 mL vs. 102.52 ± 8.15 mL; p = 0.4136). These results suggest that orthopaedic surgery robot for the treatment of longitudinal sacrum fracture is safer and provides less irradiation than the traditional freehand methods.

Comparison of screw placement guided by O-arm navigation and ultrasound volume navigation in minimally invasive transforaminal lumbar interbody fusion

To compare the effectiveness of O-arm navigation and ultrasound volume navigation (UVN) in guiding screw placement during minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) surgery. Sixty patients who underwent MIS-TLIF surgery for lumbar disc herniation between June 2022 and June 2023 and met the selection criteria were included in the study. They were randomly assigned to group A (screw placement guided by UVN during MIS-TLIF) or group B (screw placement guided by O-arm navigation during MIS-TLIF), with 30 cases in each group. There was no significant difference in baseline data, including gender, age, body mass index, and surgical segment, between the two groups ( P>0.05). Intraoperative data, including average single screw placement time, total radiation dose, and average single screw effective radiation dose, were recorded and calculated. Postoperatively, X-ray film and CT scans were performed at 10 days to evaluate screw placement accuracy and assess facet joint violation. Pearson correlation and Spearman correlation analyses were used to observe the relationship between the studied parameters (average single screw placement time and screw placement accuracy grading) and BMI. The average single screw placement time in group B was significantly shorter than that in group A, and the total radiation dose of single segment and multi-segment and the average single screw effective radiation dose in group B were significantly higher than those in group A ( P<0.05). There was no significant difference in the total radiation dose between single segment and multiple segments in group B ( P>0.05), while the total radiation dose of multiple segments was significantly higher than that of single segment in group A ( P<0.05). No significant difference was found in the accuracy of screw implantation between the two groups ( P>0.05). In both groups, the grade 1 and grade 2 screws broke through the outer wall of the pedicle, and no screw broke through the inner wall of the pedicle. There was no significant difference in the rate of facet joint violation between the two groups ( P>0.05). In group A, both the average single screw placement time and screw placement accuracy grading were positively correlated with BMI ( r=0.677, P<0.001; r=0.222, P=0.012), while in group B, neither of them was correlated with BMI ( r=0.224, P=0.233; r=0.034, P=0.697). UVN-guided screw placement in MIS-TLIF surgery demonstrates comparable efficiency, visualization, and accuracy to O-arm navigation, while significantly reducing radiation exposure. However, it may be influenced by factors such as obesity, which poses certain limitations.

Evaluating a cutting-edge augmented reality-supported navigation system for spinal instrumentation

ObjectiveDorsal instrumentation using pedicle screws is a standard treatment for multiple spinal pathologies, such as trauma, infection, or degenerative indications. Intraoperative three-dimensional (3D) imaging and navigated pedicle screw placement are used at multiple centers. For the present study, we evaluated a new navigation system enabling augmented reality (AR)-supported pedicle screw placement while integrating navigation cameras into the reference array and drill guide. The present study aimed to evaluate its clinical application regarding safety, efficacy, and accuracy.MethodsA total of 20 patients were operated on between 06/2021 and 01/2022 using the new technique for intraoperative navigation. Intraoperative data with a focus on accuracy and patient safety, including patient outcome, were analyzed. The accuracy of pedicle screw placement was evaluated by intraoperative CT imaging.ResultsA median of 8 (4–18) pedicle screws were placed in each case. Percutaneous instrumentation was performed in 14 patients (70%). The duration of pedicle screw placement (duration scan–scan) was 56 ± 26 (30–107) min. Intraoperative screw revision was necessary for 3 of 180 pedicle screws (1.7%). Intraoperatively, no major complications occurred—one case of delay due to software issues and one case of difficult screw placement were reported.ConclusionThe current study's results could confirm the use of the present AR-supported system for navigated pedicle screw placement for dorsal instrumentation in clinical routine. It provides a reliable and safe tool for 3D imaging-based pedicle screw placement, only requires a minimal intraoperative setup, and provides new opportunities by integrating AR.

The Use of a Robotic Arm for Fixation of Pelvic Fractures.

The objective of this study was to evaluate unplanned cortical or neuroforaminal violation of iliosacral and transsacral screw placement using fluoroscopy versus screw placement using a robotic arm. This is a prospective cohort study. Single surgeon, single North American level 1 trauma center. Radiographic and clinical data for 21 consecutive adult trauma patients with pelvic ring fractures undergoing surgical treatment were prospectively collected. Treatment consisted of iliosacral and/or transsacral screws with or without anterior fixation. Ten patients were treated with the assistance of a robotic arm. Eleven patients were treated with standard fluoroscopic techniques. Thirty-two screws were placed and evaluated with postoperative computed tomography or O-arm spins to assess unplanned cortical or neuroforaminal violation. Violations were graded according to the Gertzbein and Robbins system for pedicle screw violation, categorizing screw violation in 2-mm increments. The postoperative images were blindly reviewed by 5 fellowship-trained orthopaedic traumatologists. The treating surgeon was excluded from review. The Mann-Whitney U test on the Gertzbein and Robbins system results demonstrated significantly (P = 0.02) fewer violations with robotic assistance. χ2 analysis of whether there was a cortical violation of any distance demonstrated significantly (P = 0.003) fewer cortical violations with robotic assistance. There were no neurovascular injuries in either group. Robotic assistance demonstrated significantly fewer unplanned cortical or neuroforaminal violations. Further research is needed with additional surgeons and sites to evaluate the accuracy of iliosacral and transsacral screw placement with robotic assistance. Therapeutic, level II.

A Novel pedicle screw placement Surgery Based on Integration of Surgical guides and Augmented Reality.

Augmented reality is a new technology that, when applied to spinal surgery, offers the potential for efficient, safe, and accurate placement of pedicle screws. This study investigated whether augmented reality combined with a guide board improved the safety and accuracy of pedicle screw placement compared to traditional free-hand screw placement. Four trainers were divided into augmented reality navigation and free-hand groups. Each group consisted of a novice and an experienced spine surgeon. A total of 80 pedicle screws were implanted. First, the AR group reconstructed the 3D model and planned the screw insertion route according to the CT data of L2 lumbar vertebrae. Next, the Microsoft HoloLens™ 2 was used to identify the vertebral model, and the planned virtual path was superimposed on the real cone model. Next, the screw was placed according to the projected trajectory. Finally, Micron Tracker was used to measure the deviation of screws from the preoperatively planned trajectory, and pedicle screws were evaluated using the Gertzbein-Robbins scale. In the augmented reality group, the linear deviation of experienced doctors and novices was 1.59 ± 0.39 mm and 1.73 ± 0.52 mm, and the angle deviation was 2.72 ± 0.61° and 2.87 ± 0.63°, respectively. In the free-hand group, the linear deviation of experienced doctors and novices was 2.88 ± 0.58mm and 5.25 ± 0.62mm, and the angle deviation was 4.41 ± 1.18° and 7.15 ±1.45°, respectively. The screw accuracy rate was 97.5% in the augmented reality navigation group and 77.5% in the free-hand group. Augmented reality navigation improves the accuracy and safety of pedicle screw implantation compared with the traditional free-hand method and can assist inexperienced doctors in completing the surgery.

Assessing the Accuracy of Spinal Instrumentation Using Augmented Reality (AR): A Systematic Review of the Literature and Meta-Analysis.

Technological advancements, particularly in the realm of augmented reality (AR), may facilitate more accurate and precise pedicle screw placement. AR integrates virtual data into the operator's real-world view, allowing for the visualization of patient-specific anatomy and navigated trajectories. We aimed to conduct a meta-analysis of the accuracy of pedicle screw placement using AR-based systems. A systematic review of the literature and meta-analysis was performed using the PubMed/MEDLINE database, including studies reporting the accuracy of pedicle screw placement using AR. In total, 8 studies with 163 patients and 1259 screws were included in the analysis. XVision (XVS) was the most commonly used AR system (595 screws) followed by the Allura AR surgical navigation system (ARSN) (462 screws). The overall accuracy was calculated as 97.2% (95% CI 96.2-98.1% p < 0.001). Subgroup analysis revealed that there was no statistically significant difference in the accuracy rates achieved by XVS and Allura ARSN (p = 0.092). AR enables reliable, accurate placement of spinal instrumentation. Future research efforts should focus on comparative studies, cost effectiveness, operative time, and radiation exposure.

A comparative cadaveric study for percutaneous scaphoid fixation: robotic vs freehand.

To compare the robotic-assisted and the traditional freehand percutaneous scaphoid fixation in number of guidewire attempts, duration of fluoroscopy time, amount of radiation dose, and screw centrality. Twenty cadaveric specimens were randomized into either the robotic or freehand group. The scaphoids in both groups were fixed by either the same attending or resident from our hand surgery department. The operation duration, amount of radiation from intraoperative fluoroscopy, total fluoroscopy time, and the number of guidewire attempts were documented and compared. Postoperatively, all the specimens had a computed tomography (CT) scan performed, and the difference in the final position of the screw and the central axis of the scaphoid was examined. In the robotic group, all the guide wires were satisfactorily positioned within a single attempt, while the median number of attempts in the traditional freehand group was 18 (quaternion 14-65). This also meant that the surgeon in the robotic group experienced significantly lower radiation exposure dose and time as compared to the freehand group. There were no significant differences in the final screw position as compared to the central axis of the scaphoid in both groups. Although there was no difference in surgeon performance in the robotic group, the operative time for the attending was significantly lower as compared to the resident in the freehand group. Robotic-assisted surgery for scaphoid fracture fixation is superior to the traditional freehand method as it facilitates accurate screw placement with lower radiation exposure and fewer guide wire attempts.

Anatomical Evaluation of the Atlas and Analysis of Accuracy for Freehand C1 Screw Placement

Objective: Atlanto-axial fusion surgery for instability is a recognized method. However, the complex anatomical structures of the atlas and axis make freehand C1 screw placement technically challenging. This study investigated the accuracy and safety of C1 screw placement without fluoroscopic or other guidance.Methods: A retrospective analysis of radiological data was performed on patients who underwent C1 instrumentation between April 2019 and January 2023, with all procedures performed by a spine surgeon with 4 years of experience. Computed tomography was used to evaluate cortical breaches during C1 screw placement. Breach severity was categorized based on the percentage of screw diameter beyond the cortical edge. Morphometric measurements of 30 healthy individuals and 22 patients who underwent surgery were obtained from preoperative CT scans of the bilateral pedicles at the C1 level. Coronal, axial, and sagittal CT reconstructions were examined to ascertain the distance from the screw entry point to the midpoint of the C1 posterior tubercle, diameter of the central canal of the atlas, screw convergence angle, height of the C1 posterior arch at the screw entry point, and width of the canal. Results: The surgeon placed 43 C1 screws in 22 consecutive patients. Seven (16%) breaches were identified, all of which were medial C1 screws. The breaches were classified as grades I, III, and IV in 4 (57%), 2 (29%), and 1 (14%) cases, respectively. No clinical complications arose owing to the breaches.Conclusion: The freehand technique for C1 screw placement without guidance yielded accurate and safe results. However, a preoperative morphometric assessment and careful familiarization with the unique anatomy are imperative for improving screw placement precision.

EZC Guidance for Bone Screws: A Chairside Solution

Orthodontists, on a day-to-day basis, have started to use bone screws for various tooth movements such as distalization, retraction, intrusion, etc. The most common sites for the placement of bone screws are IZC6 and IZC7 with an angulation of 55° to 70°. Their added advantage is an extra-radicular site with rare chances of failure. Failure of these IZC screws may take place due to improper placement or improper angulation, which may lead to inaccurate ideal final angulation, leading to trauma to the buccal mucosa, and inter radicular placement of the IZC screw. Asymmetrically placed IZC screws on the left and right side of the mouth can lead to alteration of biomechanics. A clinician usually finds it challenging to find a purchase point of the cancellous bone and to place it at the correct angulation, which needs to be achieved for the success of the bone screw. Herein, fabrication of a guide for the accurate placement of the IZC screws, using the basic armamentarium available in a clinic, is demonstrated. The method is economical, quick, non-tedious, and accurate.

Midpoint of C7 Lateral Mass Serves as an Accurate Reference Point for the Placement of T1 Pedicle Screws: An Anatomic Study.

Free-hand placement of T1 pedicle screws can often be challenging. A reliable free-hand technique for placement of T1 pedicle screws can overcome some of the difficulties associated with poor fluoroscopy in this region. The purpose of this study was to propose a novel anatomic landmark for accurate identification of the T1 entry point using the midpoint of the C7 lateral mass as a reference point. Our hypothesis is that the midpoint of the C7 lateral mass is within 1-2 mm of the center of the T1 pedicle. Using 3-dimensional reconstruction software, the pedicle of T1 and the lateral mass of C7 were isolated to assess the location of the T1 pedicle relative to the C7 lateral mass. Specifically, the distance between the center of the T1 pedicle and the center of the C7 lateral mass was measured on 40 computed tomography scans. Furthermore, a clinical validation of this technique was performed by assessing the postoperative computed tomography scans of 53 patients undergoing cervicothoracic instrumentation. The Gertzbein and Robbins classification system was used to grade the accuracy of T1 pedicle screw placements in all patients using this technique. The average horizontal deviation + SD from centers of the T1 pedicle and the C7 lateral mass was 0.398 mm ± 0.953 mm. The T1 pedicle on average was slightly medial to the center of the C7 lateral mass. A total of 98.1% of T1 pedicle screws placed in vivo using the free-hand technique were of Grade A. In this article, we demonstrate that the center of the C7 lateral mass overlays the T1 pedicle and the optimal entry point is immediately below the midpoint of the C7 lateral mass. This approach provides a practical and accurate landmark in posterior cervicothoracic spine procedures that reduce the need for additional radiation exposure or increased operative time with image-guided techniques.