The Evaluation of a Novel Three-Dimensional Printed Expandable Pedicle Screw Sleeve Insert

2019 ◽  
Vol 13 (3) ◽  
Author(s):  
Timothy A. Burkhart ◽  
Manjunath Sadashivaiah ◽  
Jacob Reeves ◽  
Paraham Rasounlinejad

When used in combination with decompression, spinal fusion is a successful procedure for treating patients with spinal stenosis and degenerative spondylolisthesis. While a number of auxiliary devices have been proposed to enhance the fixation of the screw within the pedicle and vertebral body, there is conflicting information regarding the efficacy of their use. Therefore, the aim of this study was to determine the ability of a novel expandable pedicle screw to improve the fixation of the pedicle screw within the pedicle and vertebral body. A three-dimensional (3D) printed, screw sleeve was designed that expanded within the pedicle and vertebral body when a standard pedicle screw was inserted into it. The left and right pedicle of ten (N = 10) cadaveric lumbar spine specimens (L3–L5) were randomly assigned to be instrumented with either a pedicle screw and the sleeve or a pedicle screw only. Following instrumentation, the screws were exposed to tensile load at 5 mm/min until failure. The failure force, failure deformation, and area under the force–deformation curve were determined and compared between screw conditions. There were no significant differences between the screws and sleeve, and the screw only conditions for the failure force (p = 0.24), failure displacement (p = 0.10), and area under the curve (p = 0.38). While the novel screw sleeve presented here performed as well as a screw without a sleeve, it was better than other screw augmentation devices reported previously. In addition, it is likely that this device would prove useful as an enhancement to revision.

2020 ◽  
Author(s):  
Chao Xu ◽  
Qingxian Hou ◽  
Yanchen Chu ◽  
Xiuling Huang ◽  
Wenjiu Yang ◽  
...  

Abstract Background: Through the comparison of three-dimensional CT reconstruction between the supine position and the prone position, the relative position of thoracolumbar great vessels and vertebral body was studied, and the shortest safe distance between them was measured to improve the safety of bicortical pedicle screw insertion and reduce the risk of vascular injury. Methods: Forty adults were selected to participate the research. Three-dimensional reconstruction of thoracolumbar (T9-L3) CT was performed in the prone position and the supine position. The relative distance between the Aorta/Inferior Vena Cava (IVC) and vertebral body was obtained as AVD/VVD respectively. The relative angle of the Aorta/ IVC and the vertebral body was calculated as ∠AOY/∠VOY. Self-controlled experiments were carried out in the prone and the supine positions, and the data obtained were analyzed using SPSS 22.0 statistical software. Results: The AVD of the prone position and the supine position was the shortest at T12 (3.18 ±0.68mm), but the difference was not statistically significant. The aorta of the T9-L3 segment was shifted from the anterolateral to the anteromedial. The ∠AOY of the other groups differed significantly between the prone and supine positions in all vertebrae except L1 (P < 0.05), and the aorta in the prone position was more anteromedial than that of supine position. With regard to VVD/∠VOY, there was no significant difference between the prone and supine positions (P≥0.05), and the minimum VVD of L3 segment is greater than 5.4mm. The IVC has no obvious mobility and is fixed in the range of 20 °~ 30 ° near the midline. Conclusion: When using bicortical anchoring of pedicle screws, it is safe to ensure that the protruding tips of the screw is less than 3mm. Due to the mobility of the aorta in different postures and individual differences in anatomy, the prone position CT can help doctors to make better preoperative plans and decisions.


2021 ◽  
Author(s):  
Soo Young Cho ◽  
Dong Hae Ho ◽  
Yoon Young Choi ◽  
Soomook Lim ◽  
Sungjoo Lee ◽  
...  

Abstract Recent advances in metal additive manufacturing (AM) have provided new opportunities for the design of prototypes of metal-based products and personalization of products for the fourth industrial revolution. Although metal AM, which enables fabrication of varied and sophisticated objects, is in the spotlight as a next-generation printing method, environmental issues arising during the printing process need to be addressed before it can be commercialized. Here, we demonstrate a novel mechanism for binder jetting three-dimensional (3D) printing of metals that is based on chelation triggered by an eco-friendly binding agent. Sodium salts of fruit acid chelators are used to form stable metal-chelate bridges between metal particles, which enable elaborate metal 3D printing. The strength of the 3D-printed object is improved by post-treatment, through a reduction in the porosity between the metal particles. Finally, the compatibility of the novel printing mechanism with a variety of metals is demonstrated via successful 3D printing of objects of various shapes using various metal powders. The proposed mechanism for metal 3D printing is expected to open up new avenues for the development of domestic-scale desktop 3D printing of metals.


2020 ◽  
Vol 47 (1) ◽  
pp. 82-90 ◽  
Author(s):  
Jacob M T Curtis ◽  
Emma C Foster ◽  
Sankaranarayanan Ananth ◽  
Charlotte E Eckhardt ◽  
Jeremy Knox ◽  
...  

Autotransplantation is a treatment option with high reported survival rates to replace failing teeth in the anterior maxilla. This treatment requires a multidisciplinary approach from orthodontists, paediatric dentists, restorative dentists, and oral and maxillofacial surgeons to achieve successful outcomes. Success is dependent on many factors including stage of root development, handling of the periodontal ligament, extra-alveolar time and splinting. This case report presents the novel use of digitally designed and three-dimensional (3D) printed surgical templates to aid intraoperatively and reduce the extra-alveolar time. A preoperative cone-beam computed tomography scan allowed digital planning and construction of surgical templates that replicated the exact root dimensions of impacted maxillary canines. These templates were subsequently 3D printed in resin, sterilised and utilised intraoperatively to aid socket preparation before the surgical autotransplantation.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jun Cao ◽  
Xuejun Zhang ◽  
Haonan Liu ◽  
Ziming Yao ◽  
Yunsong Bai ◽  
...  

Abstract Background Three-dimensional (3-D) printed guidance templates are being increasingly used in spine surgery. The purpose of this study was to determine if 3D printed navigation templates can improve the accuracy of pedicle screw placement and decrease the complication rate compared to freehand screw placement in the treatment of children with congenital scoliosis. Methods The records of pediatric patients with congenital scoliosis treated at our hospital from January 2017 to January 2019 were retrospectively reviewed. Patients were divided into those where a 3D printed guidance templated was used and those in which the freehand method was used for pedicle screw placement. The accuracy rate of pedicle screw placement, surgical outcomes, and complications were compared between groups. Results A total of 67 children with congenital scoliosis were included (43 males and 24 females; mean age of 4.13 ± 2.66 years; range, 2–15 years). There were 34 children in the template-assisted group and 33 in the freehand group. The excellent accuracy rate of pedicle screw placement was significantly higher in the template-assisted group (96.10% vs. 88.64%, P = 0.007). The main Cobb angle and kyphosis angle were similar between the 2 groups preoperatively and postoperatively (all, P > 0.05), and in both groups both angles were significantly decreased after surgery as compared to the preoperative values (all, P < 0.001). The degree of change of the Cobb angle of the main curve and kyphosis angle were not significantly different between the 2 groups. There were no postoperative complications in the template group and 4 in the freehand group (0% vs. 12.12%; P = 0.009). All 4 patients with complications required revision surgery.


2021 ◽  
Author(s):  
Jun Cao ◽  
Xuejun Zhang ◽  
Haonan Liu ◽  
Ziming Yao ◽  
Yunsong Bai ◽  
...  

Abstract Background: Three-dimensional (3-D) printed guidance templates are being increasingly used in spine surgery. The purpose of this study was to determine if 3D printed navigation templates can improve the accuracy of pedicle screw placement and decrease the complication rate compared to freehand screw placement in the treatment of children with congenital scoliosis. Methods: The records of pediatric patients with congenital scoliosis treated at our hospital from January 2017 to January 2019 were retrospectively reviewed. Patients were divided into those where a 3D printed guidance templated was used and those in which the freehand method was used for pedicle screw placement. The accuracy rate of pedicle screw placement, surgical outcomes, and complications were compared between groups.Results: A total of 67 children with congenital scoliosis were included (43 males and 24 females; mean age of 4.13 ± 2.66 years; range, 2-15 years). There were 34 children in the template-assisted group and 33 in the freehand group. The excellent accuracy rate of pedicle screw placement was significantly higher in the template-assisted group (96.10% vs. 88.64%, P = 0.007). The main Cobb angle and kyphosis angle were similar between the 2 groups preoperatively and postoperatively (all, P > 0.05), and in both groups both angles were significantly decreased after surgery as compared to the preoperative values (all, P < 0.001). The degree of change of the Cobb angle of the main curve and kyphosis angle were not significantly different between the 2 groups. There were no postoperative complications in the template group and 4 in the freehand group (0% vs. 12.12%; P = 0.009). All 4 patients with complications required revision surgery.


2019 ◽  
Author(s):  
Chao Xu ◽  
Qingxian Hou ◽  
Yanchen Chu ◽  
Xiuling Huang ◽  
Wenjiu Yang ◽  
...  

Abstract Background: Three-dimensional CT reconstruction of prone position could measure the relative position between the Great vessels and the thoracolumbar vertebrae. The Great vessels positions of the thoracic and lumbar segments were studied to improve the accuracy of pedicle screw insertion, reduce the risk of vascular injury. Methods: Twenty-four adults participated in the present study. Three-dimensional reconstruction of thoracolumbar (T9–L3) CT was performed in the prone and supine positions. The relative distance between the arteriovenous vessels and vertebrae distance (AVD/VVD) was obtained, respectively. The relative position angle of the arteriovenous vessel and the vertebral body was calculated as ∠AOY/∠VOY. Self-controlled experiments were carried out in the prone and supine positions. The data obtained were analyzed using SPSS 22.0 statistical software. Results: With regard to AVD, The AVD of the T12 was the smallest,> 3.2 mm. The difference among the T9, T10, L2 level was statistically significant (P < 0.05). And AVD was greater in the prone position than in the supine position; while the value of ∠AOY is the descending from T9-L3 gradually, there were statistically significant differences in ∠AOY between T9-T12, L2 and L3 in prone and supine position (P < 0.05). The aorta in the prone position was closer to the midline than that of the supine position, varying from 0°to 30°near the Y axis. With regard to VVD, there was no significant difference in contrast between the prone and supine positions (P≥0.05), and the VVD was the smallest in the L3 level> 5.4 mm. Conclusion: The pre-vertebral position of the aorta may change from T9 to L3 due to changes in body position. When the T9-L3 thoracolumbar spine disease was treated with pedicle screw double cortical fixation, the screw was safe and reliable within a range of≤ 3 mm when broken the pre-cortex .The three-dimensional reconstruction of prone position CT could be used to more accurately assess the relative position of the vertebral body and the blood vessel.


2021 ◽  
Author(s):  
Peter A J Pijpker ◽  
Jos M A Kuijlen ◽  
Bart L Kaptein ◽  
Willem Pondaag

Abstract BACKGROUND Pediatric occipitothoracic fusion can be challenging because of small size pedicles and thin occipital bone. Three-dimensional (3D) printing technology can help with accurate screw insertion but has not been described for occipital keel plate positioning so far. OBJECTIVE To describe the novel use of 3D technology to position occipital keel plates during pediatric occipitothoracic fixation. METHODS A young boy with segmental spinal dysgenesis presented with asymmetrical pyramidal paresis in all limbs. Developmental abnormities of the cervical spine caused a thinned spinal cord, and because of progressive spinal cord compression, surgical intervention by means of occipitothoracic fixation was indicated at the age of 3 yr. Because of the small-size pedicles and thin occipital bone, the pedicle screws and occipital plates were planned meticulously using 3D virtual surgical planning technology. The rods were virtually bent in order to properly align with the planned screws. By means of 3D-printed guides, the surgical plan was transferred to the operating theater. For the occipital bone, a novel guide concept was developed, aiming for screw positions at maximal bone thickness. RESULTS The postoperative course was uneventful, and radiographs showed good cervical alignment. After superimposing the virtual plan with the intraoperative acquired computed tomography, it was confirmed that the occipital plate positions matched the virtual plan and that pedicle screws were accurately inserted without signs of breach. CONCLUSION The use of 3D technology has greatly facilitated the performance of the occipitothoracic fixation and could, in the future, contribute to safer pediatric spinal fixation procedures.


2021 ◽  
Author(s):  
Jun Cao ◽  
Xuejun Zhang ◽  
Haonan Liu ◽  
Ziming Yao ◽  
Yunsong Bai ◽  
...  

Abstract Background: Three-dimensional (3-D) printed guidance templates are being increasingly used in spine surgery. The purpose of this study was to determine if 3D printed navigation templates can improve the accuracy of pedicle screw placement and decrease the complication rate compared to freehand screw placement in the treatment of children with congenital scoliosis. Methods: The records of pediatric patients with congenital scoliosis treated at our hospital from January 2017 to January 2019 were retrospectively reviewed. Patients were divided into those where a 3D printed guidance templated was used and those in which the freehand method was used for pedicle screw placement. The accuracy rate of pedicle screw placement, surgical outcomes, and complications were compared between groups.Results: A total of 67 children with congenital scoliosis were included (43 males and 24 females; mean age of 4.13 ± 2.66 years; range, 2-15 years). There were 34 children in the template-assisted group and 33 in the freehand group. The excellent accuracy rate of pedicle screw placement was significantly higher in the template-assisted group (96.10% vs. 88.64%, P = 0.007). The main Cobb angle and kyphosis angle were similar between the 2 groups preoperatively and postoperatively (all, P > 0.05), and in both groups both angles were significantly decreased after surgery as compared to the preoperative values (all, P < 0.001). The degree of change of the Cobb angle of the main curve and kyphosis angle were not significantly different between the 2 groups. There were no postoperative complications in the template group and 4 in the freehand group (0% vs. 12.12%; P = 0.009). All 4 patients with complications required revision surgery.


2021 ◽  
Author(s):  
Jun Cao ◽  
Xuejun Zhang ◽  
Haonan Liu ◽  
Ziming Yao ◽  
Yunsong Bai ◽  
...  

Abstract Background: Three-dimensional (3-D) printed templates are increasingly applied in spinal surgery, but are rarely used in the treatment of congenital scoliosis. This study aimed to evaluate the accuracy and safety of 3D printed template-assisted screw placement in the treatment of congenital scoliosis.Methods: A total of 67 patients with congenital scoliosis treated in our hospital between January 2017 to January 2019 were retrospectively included (mean age= 4.13±2.66 years, range: 2-15) and divided into the template-assistant group (n=34) and the freehand group (n=33) according to the screw placement method. The accuracy rate of pedicle screw placement, surgical outcomes, and incidence of complications were compared between groups.Results: Although the good accuracy (grade 0+ grade 1) rate of pedicle screw placement was comparable between the two groups, the excellent accuracy (grade 0) rate was significantly higher in the template-assistant group than in the freehand group (96.10% vs. 88.64%, P=0.007). The main curve Cobb's angle and Kyphosis' angle significantly decreased after surgery in both groups but without a significant intergroup difference. The template-assistant group had a significantly lower postoperative complication rate than the freehand group (0% vs. 18.18%; P=0.009). The 4 patients with postoperative complications in the freehand group all received revision surgery.Conclusion: The 3D printed templates can improve the excellent accuracy rate of screw placement and reduce postoperative complications in the treatment of congenital scoliosis, thereby improving the therapeutic efficacy.


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