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BACKGROUND: Atlantoaxial dislocation, because of its high difficulty and high risk of surgery, has been regarded as the “surgical restricted area” by the international orthopedic community. However, with the rapid development of intelligent digitization in orthopedics, robot-assisted navigation screw placement technology has been widely used in clinical practice, which significantly reduces the difficulty and risk of surgery and improves the safety of surgery. However, there are few reports on the application of this technique in the treatment of atlantoaxial dislocation. OBJECTIVE: To explore the application value of robot-assisted pedicle screw internal fixation in the treatment of atlantoaxial dislocation. METHODS: The medical records of five patients with atlantoaxial dislocation treated with C1-C2 pedicle screw fixation under robot-assisted navigation in Zhuhai Hospital of Guangdong Provincial Hospital of Chinese Medicine from October 2021 to July 2022 were retrospectively analyzed. Operation time, length of neck incision, blood loss, postoperative drainage volume, and length of hospital stay were recorded. Attention should be paid to cerebrospinal fluid leakage, vertebral artery injury, nerve injury, operative area infection and other complications. The visual analog scale score of neck pain, the spinal cord injury grade of the American Spinal Injury Association, the cervical spine score of the Japanese Orthopaedic Association, and the imaging indicators were collected before surgery and at the last follow-up. Screw placement accuracy was assessed. RESULTS AND CONCLUSION: (1) Five patients were successfully completed surgery, without vascular, nerve injury or other complications, and were followed up for 12-20 months. (2) A total of 20 cervical pedicle screws were placed in 5 patients, including 9 type A screws, 10 type B screws, and 1 type C screw. The accuracy of screw placement was 95%. (3) At the last follow-up, the visual analog scale score was (0.80±0.71) points, which was significantly lower than that before operation (4.00±2.83) points; the Japanese Orthopaedic Association score was (14.80±0.84) points, which was significantly higher than that before operation (8.00±0.71) points. Anterior atlantodental interval decreased from (7.86±3.25) mm to (2.82±0.93) mm; space available of the spinal cord increased from (6.74±1.99) mm to (12.10±3.51) mm; cervicomedullary angle increased from (133.32±13.55)° to (153.44±9.53)°; clivus-canal angle increased from (128.02±9.92)° to (143.25±12.99)°. The results of the last follow-up indexes were improved compared with those before operation, and the differences were significant (all P < 0.05). (4) Postoperative imaging follow-up showed that all patients had bone fusion in the bone graft area, and no internal fixation loosening, fracture or pull-out occurred. (5) This method can avoid relying on the doctor’s experience and hand feeling, ensure the accuracy of upper cervical screw placement, reduce the risk of surgery, and obtain satisfactory results in mid-term follow-up. [ABSTRACT FROM AUTHOR]

BACKGROUND: The angle of screw placement in anterior cervical discectomy and fusion plays a crucial role in determining the stability of the internal fixation system. OBJECTIVE: To predict the impact of different screw placement angles on the stress experienced by the internal fixation system in anterior cervical discectomy and fusion utilizing finite element analysis, with the ultimate goal of identifying the optimal screw placement angle. METHODS: A three-dimensional reconstruction method was employed to establish a mechanical model of the cervical spine, enabling the simulation of three distinct working conditions: scoliosis, uprightness, and forward flexion. In SolidWorks 2017, the anterior cervical plate and screw models were built according to different placement angles of the screws, with a as the inward offset, b as the ideal position, c as the outward offset, d as the downward offset, and e as the upward offset. The stress distribution of internal fixation system at different screw placement angles was observed, and the stress and displacement were recorded. RESULTS AND CONCLUSION: (1) By constructing a finite element model of the entire cervical spine and incorporating an anterior titanium plate, it was found that the biomechanical changes in the spine did not significantly differ based on the various angles of screw insertion on the titanium plate under the same working conditions. (2) However, microscopic analysis revealed that the outward offset (c) screw position exhibited the most effective resistance against side bending, while the downward offset (d) screw demonstrated optimal load-bearing capacity in the upright condition. Additionally, the outward deviation (c) screw displayed superior anti-bending effects in the reverse buckling condition. (3) The fixation effect of the internal fixation device remained relatively stable across different motion conditions. Although there was a 10% variation in the internal fixation effect under the three working conditions when the screw was placed inward, outward, downward, or upward, the displacement changes were minimal. These findings suggest that the requirements of load bearing, bending resistance, and flexion resistance could be simultaneously met without a specific optimal screw location in clinical practice. (4) The placement direction of titanium plate screw in anterior cervical disc-resection and fusion has little effect on the mechanical stability of the cervical spine. The screw angles in different directions have little influence on the stability of the internal fixation device in the lateral, upright, and forward flexion movements of the cervical spine. There is no need to pursue the direction of screw placement in clinical operations. [ABSTRACT FROM AUTHOR]

Objective: To compare the differences between Ultrasound Volume Navigation (UVN), O-arm Navigation, and conventional X-ray fluoroscopy-guided screw placement in Minimally Invasive Transforaminal Lumbar Interbody Fusion (MIS-TLIF) surgeries. Methods: A total of 90 patients who underwent MIS-TLIF due to lumbar disc herniation from January 2022 to January 2023 were randomly assigned to the UVN group, O-arm group, and X-ray group. UVN, O-arm navigation, and X-ray guidance were used for screw placement in the respective groups, while the remaining surgical procedures followed routine MIS-TLIF protocols. Intraoperative data including average single screw placement time, total radiation dose, and average effective radiation dose per screw were recorded and calculated. On the 10th day after surgery, postoperative X-ray and CT examinations were conducted to assess screw placement accuracy and facet joint violation. Results: There were no significant differences in general characteristics among the three groups, ensuring comparability. Firstly, the average single screw placement time in the O-arm group was significantly shorter than that in the UVN group and X-ray group (P<0.05). Secondly, in terms of total radiation dose during surgery, for single-level MIS-TLIF, the O-arm group had a significantly higher radiation dose compared to the UVN group and X-ray group (P<0.05). However, for multi-level MIS-TLIF, the X-ray group had a significantly higher radiation dose than the O-arm group and UVN group (P<0.05). In terms of average single screw radiation dose, the O-arm group and X-ray group were similar (P>0.05), while the UVN group was significantly lower than the other two groups (P<0.05). Furthermore, no significant differences were found in screw placement assessment grades among the three groups (P>0.05). However, in terms of facet joint violation rate, the UVN group (10.3%) and O-arm group (10.7%) showed no significant difference (P>0.05), while the X-ray group (26.7%) was significantly higher than both groups (P<0.05). Moreover, in the UVN group, there were significant correlations between average single screw placement time and placement grade with BMI index (r = 0.637, P<0.05; r = 0.504, P<0.05), while no similar significant correlations were found in the O-arm and X-ray groups. Conclusion: UVN-guided screw placement in MIS-TLIF surgeries demonstrates comparable efficiency, visualization, and accuracy to O-arm navigation, while significantly reducing radiation exposure compared to both O-arm navigation and X-ray guidance. However, UVN may be influenced by factors like obesity, limiting its application. [ABSTRACT FROM AUTHOR]

(1) Background: Our team has previously introduced the Single-Step Pedicle Screw System (SSPSS), which eliminates the need for K-wires, as a safe and effective method for percutaneous minimally invasive spine (MIS) pedicle screw placement. Despite this, there are ongoing concerns about the reliability and accuracy of screw placement in MIS procedures without traditional tools like K-wires and Jamshidi needles. To address these concerns, we evaluated the accuracy of the SSPSS workflow by comparing the planned intraoperative screw trajectories with the final screw positions. Traditionally, screw placement accuracy has been assessed by grading the final screw position using postoperative CT scans. (2) Methods: We conducted a retrospective review of patients who underwent lumbar interbody fusion, using intraoperative 3D navigation for screw placement. The planned screw trajectories were saved in the navigation system during each procedure, and postoperative CT scans were used to evaluate the implanted screws. Accuracy was assessed by comparing the Gertzbein and Robbins classification scores of the planned trajectories and the final screw positions. Accuracy was defined as a final screw position matching the classification of the planned trajectory. (3) Results: Out of 206 screws, 196 (95%) were accurately placed, with no recorded complications. (4) Conclusions: The SSPSS workflow, even without K-wires and other traditional instruments, facilitates accurate and reliable pedicle screw placement. [ABSTRACT FROM AUTHOR]

Objective: Intra-articular screw penetration is a probable complication of coronoid fracture fixation. Thepresent study aimed to determine the best radiography technique for visualizing the proximal radioulnar joint(PRUJ) space. Moreover, it aimed to determine the safe angle and length of the screw to avoid PRUJ penetrationduring coronoid fracture fixation.Methods: The Mimics software was used to construct a three-dimensional model of a healthy man’s forearmfrom a computer tomography scan. It was analyzed using the Solidworks software to determine the X-ray anglethat clearly showed the PRUJ space to detect penetration of screws from the coronoid process into the PRUJand determine the maximum screw angle and length that could be used without intra-articular penetration. Toverify these findings, a cadaveric study combined with radiographs was conducted.Results: To visualize PRUJ space, the optimal X-ray angle was 13º lateral to the perpendicular line when theforearm was positioned at full supination. If the coronoid process was segmented into zones 1 (closest to theradioulnar joint) to 4 (farthest from the joint), the screw could only be inserted at a right angle in zone 1. In zones2, 3, and 4, inclination angles less than 15, 35, and 60 would prevent intra-articular penetration, respectively.Conclusions: The X-rays could visualize the PRUJ space with an anteroposterior radiograph at an angle of13º ulnar deviation from the perpendicular plane. During coronoid process fracture fixation, shorter screwswith less lateral inclination were safer when inserting screws in the zones of the coronoid process adjacent tothe PRUJ.

BACKGROUND: Orthopedic robots have been widely used in clinical practice, and relevant reports have shown that they have many advantages such as minimal trauma and short surgical time. However, there is currently no clear report on how accurate they are. OBJECTIVE: To evaluate the accuracy of robot-assisted sacroiliac screw insertion. METHODS: A total of 131 patients with sacroiliac joint fracture and dislocation and sacral fracture admitted to the Department of Trauma Surgery, Gansu Provincial Hospital from January 2020 to April 2023 were retrospectively collected, including 131 S1 screws and 46 S2 screws, totaling 177 screws. They were divided into two groups based on whether robot-assisted navigation was performed. There were 63 cases of sacroiliac screws inserted under robot-assisted navigation (observation group), with 36 males and 27 females, aged 19-72 years, with a mean age of (45.3±17.6) years. Among them, 39 cases were fixed with only S1 screws, while 24 cases were fixed with S1S2 screws, resulting in a total of 87 sacroiliac screws. Under C-arm fluoroscopy, 68 cases of sacroiliac screws were inserted with bare hands (control group), including 41 males and 27 females, aged 23-67 years, with a mean age of (42.6±21.3) years. Among them, 46 cases were fixed with simple S1 screws, while 22 cases were fixed with S1S2 screws, resulting in a total of 90 sacroiliac screws. A postoperative CT scan was performed to evaluate the number of S1 screws, S2 screws, total screw level, and calculate accuracy based on the method introduced by SMITH et al. RESULTS AND CONCLUSION: (1) In the observation group, 62 S1 screws were accurately placed (62/63), with an accuracy rate of 98%. 24 S2 screws were accurately placed (24/24), with an accuracy rate of 100%. The total number of screws accurately placed was 86 (86/87), with an accuracy rate of 99%. (2) In the control group, 58 S1 screws were accurately inserted (58/68), with an accuracy rate of 85%. 19 S2 screws were accurately inserted (19/22), with an accuracy rate of 86%. The total number of screws accurately inserted was 77 (77/90), with an accuracy rate of 86%. (3) There was a statistically significant difference in the accuracy of the S1 screw, S2 screw, and total screw between the two groups (P < 0.05). It is suggested that the placement of sacroiliac screws under robot navigation has higher accuracy compared to manual placement under C-arm fluoroscopy, but still has a lower error rate in placement. [ABSTRACT FROM AUTHOR]

Pedicle screws are commonly used for posterior fixation of the lumbar spine. Inaccuracy of screw placement can lead to disastrous complications. As fluoroscopic assisted pedicle screw instrumentation is the most frequently used technique, the aim of this study was to assess the specificity, sensitivity and accuracy of intraoperative fluoroscopy to detect mediolateral screw malpositioning. We also analyzed whether the addition of an oblique view could improve these parameters. On 12 human cadavers, 138 pedicle screws were placed intentionally either with 0 to 2 mm (75 screws), with 2 to 4 mm (six medial and 12 lateral screws) and with >4 mm (22 medial and 23 lateral screws) breach of the pedicle from Th12 to L5. Three experienced spine surgeons evaluated the screw positioning in fluoroscopic AP views and 4 weeks later in AP views and additional oblique views. The surgeons' interpretation was compared with the effective screw position on postoperative CT scans. Pedicle breaches greater than 2 mm were detected in 68% with AP views and in 67% with additional oblique views (p=.742). The specificity of AP views was 0.86 and 0.93 with additional oblique views (p=<.01). The accuracy was 0.78 with AP views and 0.81 with AP + oblique views (p=.114). There was a substantial inter-reader agreement (Fleiss's kappa: 0.632). Fluoroscopic screening of pedicle screw misplacement has a limited sensitivity. Adding an oblique view improves specificity but not sensitivity and accuracy in detecting screw malpositions. When in doubt of a screw malpositioning, other modalities than a fluoroscopic assisted pedicle screw instrumentation such as intraoperative CT imaging or an intraoperative exploration of the screw trajectory must be evaluated. [ABSTRACT FROM AUTHOR]

With the development of artificial intelligence and the further deepening of medical-engineering integration, spine surgical robot-assisted (RA) technique has made significant progress and its applicability in clinical practice is constantly expanding in recent years. In this review, we have systematically summarized the majority of literature related to spine surgical robots in the past decade, and not only classified robots accordingly, but also summarized the latest research progress in RA technique for screw placement such as cervical, thoracic, and lumbar pedicle screws, cortical bone trajectory screws, cervical lateral mass screws, and S2 sacroiliac screws; guiding targeted puncture and placement of endoscope via the intervertebral foramen; complete resection of spinal tumor tissue; and decompressive laminectomy. In addition, this report also provides a detailed evaluation of RA technique’s advantages and disadvantages, and clarifies the accuracy, safety, and practicality of RA technique. We consider that this review can help clinical physicians further understand and familiarize the current clinical application status of spine surgical robots, thereby promoting the continuous improvement and popularization of RA technique, and ultimately benefiting numerous patients.

Aim: Screw used in the treatment of ankle syndesmosis diastasis can be placed in malposition. Our aim in the study is to define a new technique for sending the screws in the right direction. Materials and Methods: The ankle tomography of 188 patients was evaluated. First, the medial malleolus root was divided into three equal parts in axial CT section. Then, a screw model was drawn to fit the fibula to the concave surface in the tibia in another axial CT section where the syndesmosis joint is prominent. These two axial CT sections were placed on top of each other with computer program. Results are noted. Results: While 95.7% of the screw simulations were passing through the front 1/3, 4.3% through the middle 1/3, the screw did not pass through the rear 1/3 in any simulation. 187 of these lines passed between the most lateral peak of the fibula and 3 mm posterior. Conclusion: During diastasis surgery, the insertion site of the drill should be chosen between the sharp peak of the fibula and the 3mm posterior. When the drill is placed in this way and directed 1/3 anterior to the medial malleolus, our screw will be sent in the correct position. Our study revealed that the surgical treatment of syndesmos dissociation with screws is a landmark independent of the patient's position and the skill of the surgeon. There is no other study like this study. However, considering the consistency of our results with the literature, we believe that our study can guide surgeons in practical applications. [ABSTRACT FROM AUTHOR]

Background: A very common technique for treating spinal deformities in children and adolescents is the use of segmental screws. In order to obtain proper stability and the best possible correction, the screws must first be precisely inserted. Additional factors influencing the quality and success of the operation are the size and quality of the bone, the skills of the surgeon, and biomechanical factors, i.e., the width and length of the screws used during surgery. Our study was focused on evaluating the effect of increasing the diameter of the instrumented pedicles by pedicle screws and assessing the safety of expanding these pedicles with screws of various sizes in children with spinal deformities during the growth period, using preoperative magnetic resonance imaging and postoperative computed tomography (CT) to assess and compare preoperative size measurements from MRI to postoperative CT measurements. Methods: We obtained data for evaluation from the available medical records and treatment histories of patients aged 2 to 18 who underwent surgical treatment of spinal deformities in the years 2016–2023. In 230 patients (28 male and 202 female), 7954 vertebral bodies were scanned by preoperative MRI, and 5080 pedicle screws were inserted during surgery, which were then assessed by postoperative CT scan. For the most accurate assessment, patients were classified into three age groups: 2–5 years (Group 1), 6–10 years (Group 2), and 11–18 years (Group 3). In addition, we studied implant subgroups: vertebral bodies with inserted pedicles of screw sizes 5.0 mm and 5.5 mm (Group S), and pedicles of screw sizes 6.0 mm, 6.5 mm, and 7.0 mm (Group L). Results: The morphology of pedicles (Lenke classification) analyzed before surgery using MRI was 55.2% type A, 33.8% type B, 4.7% type C, and 6.3% type D. The postoperative lateral and medial breaches were noted, and these did not cause any complications requiring revision surgery. The mean pedicle diameter before surgery for T1–L5 vertebral pedicles was between 3.79 (1.44) mm and 5.68 (1.64) mm. The mean expanding diameter of pedicles after surgery for T1–L5 vertebral pedicles ranged from 1.90 (0.39) mm to 2.92 (0.28) mm, which corresponds to the extension of the pedicle diameter in the mean range of 47% (4.1)–71% (3.0). We noted that the mean vertebral pedicle expansion was 49% in Group 1, 52% in Group 2, and 62% in Group 3 (N.S.), and the mean expansion for 7.0 mm screw pedicles was 78%. Conclusions: Our study confirms that there is a wide range of expansion of the vertebral pedicle during screw insertion (up to 78%) with a low risk of lateral or medial breaches and without an increased risk of complications. The larger the diameter of the screw inserted into the pedicle, the more the pedicle expands. Pedicle measurements by preoperative MRI may be helpful for sufficient reliability in preoperative planning. [ABSTRACT FROM AUTHOR]

Background: The current method of treatment of spinal deformities would be almost impossible without pedicle screws (PS) placement. There are only a few studies evaluating the safety of PS placement and possible complications in children during growth. The present study was carried out to evaluate the safety and accuracy of PS placement in children with spinal deformities at any age using postoperative computed tomography (CT) scans. Methods: 318 patients (34 males and 284 females) who underwent 6358 PS fixations for pediatric spinal deformities were enrolled in this multi-center study. The patients were divided into three age groups: less than 10 years old, 11–13 years old, and 14–18 years old. These patients underwent postoperative CT scans and were analyzed for pedicle screw malposition (anterior, superior, inferior, medial, and lateral breaches). Results: The breach rate was 5.92% for all pedicles. There were 1.47% lateral and 3.12% medial breaches for all pedicles with tapping canals, and 2.66% lateral and 3.84% medial breaches for all pedicles without a tapping canal for the screw. Of the 6358 screws placed in the thoracic, lumbar, and sacral spine, 98% of the screws were accurately placed (grade 0, 1, and juxta pedicular). A total of 56 screws (0.88%) breached more than 4 mm (grade 3), and 17 (0.26%) screws were replaced. No new and permanent neurological, vascular, or visceral complications were encountered. Conclusions: The free-hand technique for pedicle screw placement in the acceptable and safety zone in pedicles and vertebral bodies was 98%. No complications associated with screw insertion in growth were noted. The free-hand technique for pedicle screw placement can be safely used in patients at any age. The screw accuracy does not depend on the child's age nor the size of the deformity curve. Segmental instrumentation with posterior fixation in children with spinal deformities can be performed with a very low complication rate. Navigation of the robot is only an auxiliary tool in the hands of the surgeons, and the result of the work ultimately depends on the surgeons. [ABSTRACT FROM AUTHOR]

Abstract Introduction Calcaneal fractures, especially those involving the articular surface, should be anatomically reduced as much as possible. Fixing the fracture by placing a screw into the sustentaculum tali from the lateral side of the calcaneus is generally considered to be the key to successful surgery. However, due to the limited visibility during surgery, it is not easy to place screws into the sustentaculum tali accurately. The purpose of this study was to explore a new fluoroscopy method for the sustentaculum tali and verify the value of this method in improving screw placement accuracy. Methods In this study, a total of 42 human foot and ankle specimens were dissected and measured. The shape and position of the sustentaculum tali were observed, and the influence of adjacent bones on imaging findings was analysed. The axial and frontal X-ray fluoroscopy method to view the sustentaculum tali was formulated, and the appropriate projection angle through anatomical and image measurements was explored. Thirty specimens were randomly selected for screw placement, and the direction of the screw was dynamically adjusted under the new imaging method. The success rate of sustentacular screw placement was evaluated. Results The anteversion angles of the sustentaculum tali were 30.81 ± 2.21° and 30.68 ± 2.86° by anatomical and imaging measurements, respectively. There was no statistically significant difference in the anteversion angle between the two measurement methods. Harris heel views should be obtained at 30° to identify the sustentaculum tali on axial X-ray images. Frontal X-ray imaging was performed perpendicular to this projection angle. Through frontal and axial X-ray imaging, the position and shape of the sustentaculum tali can be clearly observed, and these factors are seldom affected by adjacent bones. Under the new fluoroscopy method, the screws were placed from the anterior region of the lateral wall of the calcaneus to the sustentaculum tali. A total of 60 screws were placed in the 30 specimens; of these, 54 screws were in good position, 2 screws penetrated the cortical bone, and 4 screws did not enter the sustentaculum tali. The success rate of sustentacular screw placement was 90% (54/60). Conclusions Axial and frontal X-ray images of the sustentaculum tali can clearly show the shape of the structure, which improves sustentacular screw placement accuracy.

Background Atlantoaxial instability is an important disorder that causes serious symptoms such as difficulties in walking, limited neck mobility, sensory deficits, etc. Atlantal lateral mass screw fixation is a surgical technique that has gained important recognition and popularity. Because accurate drilling area for screw placement is of utmost importance for a successful surgery, we aimed to investigate morphometry of especially the posterior part of C1. Methods One hundred and fifty-eight human adult C1 dried vertebrae were obtained. Measurements were performed directly on dry atlas vertebrae, and all parameters were measured by using a digital caliper accurate to 0.01 mm for linear measurements. Results The mean distance between the tip of the posterior arch and the medial inner edge of the groove was found to be 10.59 ± 2.26 and 10.49 ± 2.20 mm on the right and left, respectively. The mean distance between the tip of the posterior arch and the anterolateral outer edge of the groove was 21.27 ± 2.28 mm (right: 20.96 ± 2.22 mm; left: 21.32 ± 2.27 mm). The mean height of the screw entry zone on the right and left sides, respectively, were 3.86 ± 0.81 and 3.84 ± 0.77 mm. The mean width of the screw entry zone on both sides was 13.15 ± 1.17 and 13.25 ± 1.3 mm. Conclusion Our result provided the literature with a detailed database for the morphometry of C1, especially in relation to the vertebral artery groove. We believe that the data in the present study can help surgeons to adopt a more accurate approach in terms of accurate lateral mass screw placement in atlantoaxial instability. [ABSTRACT FROM AUTHOR]

Abstract Background The objective of the study was to explore the feasibility and efficacy of computer-assisted screw inserting planning (CASIP) in the surgical treatment for severe spinal deformity. Methods A total of 50 patients participated in this prospective cohort study. 25 patients were allocated into CASIP group and 25 patients were in Non-CASIP group. The demographic data, radiological spinal parameters were documented and analyzed. Each pedicle screw insertion was classified as satisfactory insertion or unsatisfactory insertion based on Gertzbein-Robbins classification. The primary outcome was the accuracy of pedicle screw placement. The secondary outcomes were the rate of puncturing screws, estimated blood loss, surgical time, correction rate and other radiological parameters. Results A total of 45 eligible patients completed the study. 20 patients were in CASIP group and 25 patients were in Non- CASIP group. The accuracy of pedicle screw placement in CASIP Group and Non-CASIP Group were (92.0 ± 5.5) % and (82.6 ± 8.3) % (P

Purpose : Both robots and navigation are effective strategies for optimizing screw placement, as compared to freehand placement. However, few studies have compared the accuracy and efficiency of these two techniques. Thus, the purpose of this study is to compare the accuracy and efficiency of robotic and navigation-assisted screw placement in the spinal vertebrae. Methods: The 24 spine models were divided into a robot- and navigation-assisted groups according to the left and right sides of the pedicle. The C-arm transmits image data simultaneously to the robot and navigates using only one scan. After screw placement, the accuracy of the two techniques were compared using "angular deviation" and "Gertzbein and Robbins scale" in different segments (C1–7, T1–4, T5–8, T9–12, and L1–S1). In addition, operation times were compared between robot- and navigation-assisted groups. Results: Robots and navigation systems can simultaneously assist in screw placement. The robot-assisted group had significantly less angular deviation than the navigation-assisted group from C1 to S1 (p < 0.001). At the C1–7 and T1–4 segments, the robot-assisted group had a higher rate of acceptable screws than the robot-assisted group. However, at the T5–8, T9–12, and L1–S1 segments, no significant difference was found in the incidence of acceptable screws between the two groups. Moreover, robot-assisted screw placement required less operative time than navigation (p < 0.05). Conclusion: The robot is more accurate and efficient than navigation in aiding screw placement. In addition, robots and navigation can be combined without increasing the number of fluoroscopic views. [ABSTRACT FROM AUTHOR]

Purpose: To provide a baseline for comparison with future advancements, this study determined the accuracy of preoperative planning of pedicle screw placement using standard radiographs for posterior fusion (PSF) for adolescent idiopathic scoliosis (AIS). Methods: Ninety-five patients with AIS planned for PSF were prospectively enrolled. Preoperative planning was based upon standard upright posteroanterior and lateral radiographs. The planned number of screws to be placed at each level was recorded. Intraoperatively, all screws were placed by freehand technique. The number of successfully placed screws and the reasons for abandoning screw placement were documented. Results: There were a total of 1783 pedicle screws planned preoperatively. The average planned implant density was 2.0 implants/vertebra. A total of 1723 (96.6%) of the planned screws were placed successfully. Fourteen (0.8%) screws were abandoned after attempted placement (range 0–2 screws/case). Of 241 screws planned in pedicles noted to be "hypoplastic," 13 resulted in the use of a hook or no instrumentation. The placement was not attempted for 49 (range 0–7/case) planned screws due to intraoperative decision-making and a sense that the curve was flexible enough not to require every screw. Three cases (3.2%) required instrumentation of an additional level. Conclusions: Standard spine radiographs allow for accurate preoperative planning for freehand pedicle screw placement in AIS. Ninety-seven percent of planned screws were placed successfully. The primary reason for deviation from the preoperative plan was intraoperative surgeon decision-making rather than difficulty with screw placement. This study will serve as a baseline when considering the utilization of navigation in PSF for AIS. [ABSTRACT FROM AUTHOR]

Introduction: Calcaneal fractures, especially those involving the articular surface, should be anatomically reduced as much as possible. Fixing the fracture by placing a screw into the sustentaculum tali from the lateral side of the calcaneus is generally considered to be the key to successful surgery. However, due to the limited visibility during surgery, it is not easy to place screws into the sustentaculum tali accurately. The purpose of this study was to explore a new fluoroscopy method for the sustentaculum tali and verify the value of this method in improving screw placement accuracy. Methods: In this study, a total of 42 human foot and ankle specimens were dissected and measured. The shape and position of the sustentaculum tali were observed, and the influence of adjacent bones on imaging findings was analysed. The axial and frontal X-ray fluoroscopy method to view the sustentaculum tali was formulated, and the appropriate projection angle through anatomical and image measurements was explored. Thirty specimens were randomly selected for screw placement, and the direction of the screw was dynamically adjusted under the new imaging method. The success rate of sustentacular screw placement was evaluated. Results: The anteversion angles of the sustentaculum tali were 30.81 ± 2.21° and 30.68 ± 2.86° by anatomical and imaging measurements, respectively. There was no statistically significant difference in the anteversion angle between the two measurement methods. Harris heel views should be obtained at 30° to identify the sustentaculum tali on axial X-ray images. Frontal X-ray imaging was performed perpendicular to this projection angle. Through frontal and axial X-ray imaging, the position and shape of the sustentaculum tali can be clearly observed, and these factors are seldom affected by adjacent bones. Under the new fluoroscopy method, the screws were placed from the anterior region of the lateral wall of the calcaneus to the sustentaculum tali. A total of 60 screws were placed in the 30 specimens; of these, 54 screws were in good position, 2 screws penetrated the cortical bone, and 4 screws did not enter the sustentaculum tali. The success rate of sustentacular screw placement was 90% (54/60). Conclusions: Axial and frontal X-ray images of the sustentaculum tali can clearly show the shape of the structure, which improves sustentacular screw placement accuracy. [ABSTRACT FROM AUTHOR]

Background: The objective of the study was to explore the feasibility and efficacy of computer-assisted screw inserting planning (CASIP) in the surgical treatment for severe spinal deformity.Methods: A total of 50 patients participated in this prospective cohort study. 25 patients were allocated into CASIP group and 25 patients were in Non-CASIP group. The demographic data, radiological spinal parameters were documented and analyzed. Each pedicle screw insertion was classified as satisfactory insertion or unsatisfactory insertion based on Gertzbein-Robbins classification. The primary outcome was the accuracy of pedicle screw placement. The secondary outcomes were the rate of puncturing screws, estimated blood loss, surgical time, correction rate and other radiological parameters.Results: A total of 45 eligible patients completed the study. 20 patients were in CASIP group and 25 patients were in Non- CASIP group. The accuracy of pedicle screw placement in CASIP Group and Non-CASIP Group were (92.0 ± 5.5) % and (82.6 ± 8.3) % (P < 0.05), and the rate of puncturing screws were (0 (0-0)) % and (0 (0-6.25)) % (P < 0.05). The median surgical time were 280.0 (IQR: 260.0-300.0) min and 310 (IQR: 267.5-390.0) min in two group and showed significant statistic difference (P < 0.05).Conclusions: CASIP has good feasibility and can gain a more accurate and reliable instruments fixation, with which spine surgeons can make a detailed and personalized screw planning preoperatively to achieve satisfying screw placement. [ABSTRACT FROM AUTHOR]

Study Design: Cross-sectional analysis of defined parameters of patients who underwent the presented technique. Patients undergoing thoracic spine fixation for various pathologies.Objective: This technique attempts to limit the incision size in extrapleural thoracotomy for multi-level spinal fixation.Summary of Background Data: Dorsal spine is traditionally approached by either transpleural or extrapleural approach. The extrapleural approach carries a limitation of being restricted in number of levels it can address. By incrementally modifying the present technique, we were able to employ the approach in greater number of levels with lesser morbidities.Method: Classical extrapleural thoracotomy approach is employed with incision size limited to the levels of pathology (~5 cm). Thereafter, proper exposure using Kittner dissection and defining of screw entry points follows. Stab incision is made and screws placed percutaneously through a K-wire-defined trajectory.Results: Eighteen patients underwent fixation through this technique, of which 11 were infectious, four were traumatic, and the rest were neoplastic in pathology. None except three patients had ICU stay of more than 1 day. All patients had a pain score of 6 or lower except for two.Conclusion: Combining the technique of percutaneous screw placement with traditional extrapleural thoracotomy reduces the size of the incision, tissue damage, and morbidity while reducing the cost and duration of hospitalization without comprising the extent of pathology that can be dealt with. [ABSTRACT FROM AUTHOR]

Objective: Simulation-based training is a technique, which evokes or replicates substantial aspects of the real world in a fully interactive fashion and replaces and amplifies real experiences with guided ones, which are generally immersive. Materials and Methods: Twenty-five junior surgeons (20 orthopedic, 5 neurosurgeon) who were not involved in previous posterior cervical spine instrumentation participated in this study. Before the procedures, all surgeons received 2-hour lecture about cervical spine anatomy and screw insertion techniques. Group 1 (10 surgeons) underwent virtual reality simulation with haptic feedback for 20 min, group 2 (15 surgeons) were attended video sessions with experienced surgeons for 20 min for posterior cervical instrumentation training. After, all junior surgeons applied C1-2 screw, C3-4-5 lateral mass screws, and C6-7 cervical pedicle screws to saw bones. All saw bones underwent computerized tomography (CT) imaging and a blinded radiologist reviewed the CT images. Results: Group 1 applied 70 screws and group 2 applied 105 screws. Group 1 showed a 12% misplacement ratio, while group 2 showed a 19% misplacement ratio and 4% rate of a possible vertebral artery trace penetration (p=0.026). Conclusion: According to the results acquired from this study, we observed a lower cervical spine screw misplacement ratio in those who trained with VR based haptic enabled simulation before performing cervical posterior instrumentation. [ABSTRACT FROM AUTHOR]

Purpose: Intra-operative image acquisition coupled with navigation aims to increase screw placement accuracy, and it is particularly helpful in complex spinal procedures. The aim of this study is to analyze the accuracy and reliability of posterior atlanto-axial fixation using spinal navigation combined with intra-operative 3D isocentric C-arm. Methods: We retrospectively reviewed all patients presenting with C1–C2 instability and treated by posterior atlanto-axial fixation in our center between December 2016 and September 2018. Screw positioning was guided by intra-operative navigation, registered with surface matching procedure on a previously obtained CT scan and controlled by intra-operative 3D isocentric C-arm. Age, sex, pre- and post-operative neurological status, duration of surgery, presence/absence of vertebral artery injury, and screw placement were retrospectively collected from patients' records. All patients underwent clinical and radiological follow-up at three months after surgery. Radiological assessment of screw positioning was performed by an independent radiologist using the Gertzbein and Robbins grading. Results: N = 11 (7F, 4 M) consecutive patients were included, with a mean age of 72 years (range from 51 to 85). N = 44 navigated screws were inserted and controlled with intra-operative 3D fluoroscopy at the end of the procedure. An acceptable screw positioning (Gertzbein-Robbins grade A and B) was obtained in all cases (100%). No vertebral artery injury was observed. Mean operating time was 123 minutes. At three months, no screw loosening or displacement was observed. Conclusion: In our experience, spinal navigation coupled with intra-operative 3D fluoroscopy proved to be reliable and safe for C1–C2 screw placement. [ABSTRACT FROM AUTHOR]

Objective: 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., Methods: 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., Results: 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)., Conclusion: 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.

Study Design: Prospective case series., Objective: SSPSS (single step pedicle screw system) was developed for minimally invasive spine surgery. We performed this study to report on safety, workflow, and our initial clinical experience with this novel technique., Methods: The prospective study was conducted on patients who underwent pedicle screw fixation between October 2017 and April 2018 using a novel single step 3D navigated pedicle screw system for MIS. Outcome measurements were obtained from intraoperative computerized tomography. The images were evaluated to determine pedicle wall penetration. We used a grading system to assess the severity of the pedicle wall penetration. Breaches were classified as grade 1 (<2 mm), grade 2 (2-4 mm), or grade 3 (<4 mm), 1 and as cranial, caudal, medial, and lateral., Results: Our study includes 135 screws in 24 patients. SSPSS eliminated K-wires and multiple steps traditionally necessary for MIS pedicle screw insertion. The median time per screw was 2.45 minutes. 3 screws were corrected intraoperatively. Pedicle wall penetration occurred in 14 screws (10%). Grade 1 breaches occurred in 4 screws (3%) and grade 2 breaches occurred in 10 screws (7%). Lateral breaches were observed more often than medial breaches. The accuracy rate in our study was 90% (Grade 0 breach). No revision surgeries were needed and no complications occurred., Conclusions: Our study suggests that SSPSS could be a safe, accurate, and efficient tool. Our accuracy rate is comparable to that found in the literature.