3D printed templates improve the accuracy and safety of pedicle screw placement in the treatment of pediatric congenital scoliosis

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.

Surgical outcomes in children under 10 years old in the treatment of congenital scoliosis due to single nonincarcerated thoracolumbar hemivertebra: according to the age at surgery

Purpose Hemivertebra is one of the common pathogenesis of congenital scoliosis. The timing of operation is undefined. Our study compared the surgical outcomes in children under age 10 years with scoliosis due to single nonincarcerated thoracolumbar hemivertebra according to the age at surgery. Methods From January 2009 to August 2017, we retrospectively investigated 34 consecutive cases of congenital scoliosis treated by posterior hemivertebra resection and fusion with pedicle screw fixation. All cases were divided into two groups according to the age at surgery and followed-up for at least 2 years, group 1 (≤ 5 years old), and group 2 (5 to 10 years old). Results The mean Cobb angle of the main curve was improved from 48.58° to 15.53° (68.05%) in group 1, and from 43.73° to 11.33° (75.43%) in group 2. The segmental curve was improved from 44.16° to 11.53° (74.64%) in group 1, and the segmental curve was consistent with the main curve in group 2. The mean segmental kyphosis was improved from 27.50° to 8.42° (67.40%) in group 1, and from 29.00° to 5.00° (84.73%) in group 2. Five patients developed distal adding-on, and four patients were found proximal junctional kyphosis during the follow-up. Conclusion Not all the deformities caused by single nonincarcerated thoracolumbar hemivertebra would progress greatly with the spinal growth. No significant statistical differences were found in the coronal and sagittal correction rate between the two groups. A limited delayed surgery after 5 years but before 10 years of age with close follow-up can achieve satisfied results.

Conservative treatment of a scoliosis patient after two heart surgeries in early childhood – A case report

Introduction: This is a case report of a juvenile female patient with scoliosis following two heart surgeries for congenital heart disease (CHD).Patient presentation, management and outcome: Initially, the premenarchial female was 9 years old and had a Tanner stage 2–3 with a single thoracic curve of 65° Cobb. Because of the high risk for progression, immediate brace treatment was proposed as the father declined surgery. The patient received intensive treatment according to the Schroth Best Practice® programme and a Gensingen Brace® designed for large thoracic curves. Over the 18 months following the initial visit, she received two additional braces. As a result, the progression of the main curve was prevented. The patient continues to maintain an improved cosmetic result and is currently at a Risser 2.Conclusion: Surgery performed for CHD in rare cases may lead to stiff spinal deformity as a consequence of that surgery. Progression of a severe and stiff curve was prevented during the most vulnerable phase of the pubertal growth spurt with an improved clinical result. Therefore, we assume that the patient may have a normal life in adulthood with minor restrictions only. Supported by pattern-specific high correction exercises and braces, these typical single thoracic curves can be re-compensated to a more balanced appearance, less prone to progression in adulthood.Clinical implications: Because of the relative high risks of spinal fusion and the long-term unknowns of such an intervention, high-impact conservative treatment should be implemented first before surgical correction is considered.

Comparative analysis on rheological characteristics of different modified asphalt based on DSR and BBR evaluation

Purpose In order to evaluate the rheological properties of asphalt more comprehensively and effectively, and to explore and discuss the practicability of relevant models in the evaluation of the rheological properties of asphalt. Design/methodology/approach Based on the rheological and viscoelastic theories, temperature scanning, frequency scanning and multiple stress creep recovery (MSCR) tests of different modified asphalt were carried out by dynamic shear rheometer (DSR) to obtain relevant viscoelastic parameters and evaluate the high temperature properties of different modified asphalt. Based on the time-temperature equivalence principle, the main curve was constructed to study the viscoelastic properties of asphalt in a wider frequency domain. The main curve was fitted with the CAM model, and the rheological properties of different modified asphalt were evaluated through the analysis of model parameters. The creep stiffness and creep velocity of different modified asphalt were obtained through the rheological test of bending beam (BBR), and the low-temperature performance of different modified asphalt was analyzed by using Burgers model to fit the creep compliance. Findings The results show that the high temperature rheological properties of several modified asphalt studied in the test are ranked from best to worst as follows: PE modified asphalt > SBS modified asphalt > SBR modified asphalt. Short-term aging can improve the high temperature performance of asphalt, and different types of modifiers can promote or inhibit this improvement effect. Based on BBR test and Burgers model fitting analysis, SBR modified asphalt has the best low temperature performance, followed by SBS modified asphalt, while PE modified asphalt has poor low temperature performance, so it is not suitable to be used as road material in low temperature area. Originality/value Combined with effective evaluation methods, the rheological properties of asphalt at different temperatures and angles were systematically evaluated, and the evolution of rheological properties of asphalt characterized by model parameters was further analyzed by advanced model simulation.

3D Printed Templates Improve the Accuracy and Safety of Pedicle Screw Placement in the Treatment of Pediatric Congenital Scoliosis

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.

CONSERVATIVE IDIOPATHIC SCOLIOSIS TREATMENT WITH BRACE PRODUCED USING 3D TECHNOLOGY

ABSTRACT Objective To evaluate the immediate correction capacity of the Wood-Chêneau-Rigo brace (WCR), produced using digital technological resources and robotic engineering, in primary and secondary curves of adolescent idiopathic scoliosis (AIS). Methods A retrospective study was conducted of 138 patients with a diagnosis of AIS and who received a WCR brace from a laboratory that makes orthoses and orthopedic prostheses between 2019 and 2021. These individuals were submitted to an independent analysis of the radiographic parameters by a single researcher, the main outcome of which was the standardized measurement of the main and secondary curves using the Cobb method. The radiographs analyzed were performed in orthostasis before and immediately after the adaptation of the brace on the patient. The correction capacity was calculated as the ratio of the difference between the pre- and post-brace curves to the pre-brace curve. Results The mean correction with the WCR was 48.4% for the main curve and 41.0% for the secondary curve. The level of correction of the main curve was significantly higher in patients with a main curve with the apex of convexity in the thoracolumbar region (p = 0.004), especially in the left thoracolumbar region (p = 0.010); curves of magnitude between 10º and 24.9º (p <0.001); and curves classified as simple (p <0.001). Conclusion The use of the WCR, which is produced using modern technological resources, was effective in the immediate correction of AIS. Long-term studies on this new modality of conservative scoliosis treatment are necessary. Level of evidence III; Retrospective study.

PRELIMINARY RESULTS OF THE BIPOLAR TECHNIQUE IN THE TREATMENT OF NEUROMUSCULAR SCOLIOSIS

ABSTRACT Objective To present the preliminary results of the bipolar technique for the surgical treatment of neuromuscular spine deformities. Methods Five patients with neuromuscular scoliosis (cerebral palsy – 3 patients, spinal amyotrophy – 1 patient, and genetic syndrome – 1 patient) underwent surgical treatment using the bipolar technique and were evaluated 12 months after the operation. Results General care and the ability to sit improved in all patients. The main curve ranged from 64.7 to 84.1 degrees (mean 70.58 ± 7.1) in the preoperative period and from 2.6 to 50.3 degrees (mean 25.50 ± 16.0) in the postoperative period with 64% correction. Corrections of pelvic obliquity (85%), T4-T12 kyphosis (43%), the Pisa angle (69%) and the sacroclavicular angle (60%) were observed 12 months following surgery. Postoperative infection (2 patients) and pneumonia (1 patient) were the complications observed. Conclusion The bipolar technique presented good clinical and radiological results associated with low morbidity in the treatment of neuromuscular spine deformities. Level of evidence IV; Case series.

Surgical Outcomes in Children Under 10 Years Old in The Treatment of Congenital Scoliosis Due To Single Nonincarcerated Thoracolumbar Hemivertebra: According To The Age At Surgery

Purpose Hemivertebra is one of the common pathogenesis of congenital scoliosis. The timing of operation is undefined. Our study compared the surgical outcomes in children under age 10 years with scoliosis due to single nonincarcerated thoracolumbar hemivertebra according to the age at surgery. Methods From January 2009 to August 2017, we retrospectively investigated 34 consecutive cases of congenital scoliosis treated by posterior hemivertebra resection and fusion with pedicle screw fixation. All cases were devided into two groups according to the age at surgery and followed-up for at least 2 years. Group 1 (≤ 5 years old), and group 2 (5 to 10 years old). Results The mean Cobb angle of the main curve was improved from 48.58° to 15.53° (68.05%) in group 1, and from 43.73° to 11.33°(75.43%) in group 2. The segmental curve was improved from 44.16° to 11.53°(74.64 %) in group 1, and the segmental curve was consistent with the main curve in group 2. The mean segmental kyphosis was improved from 27.50° to 8.42°(67.40%) in group 1, and from 29.00° to 5.00° (84.73%) in group 2. 5 patients developed distal adding-on and 4 patients were found proximal junctional kyphosis during the follow up. Conclusions Not all the deformities caused by single nonincarcerated thoracolumbar hemivertebra would progress greatly with the spinal growth. A limited delayed surgery after 5 years but before 10 years of age with close follow-up can achieve good results, the occurrence of distal adding-on might be reduced, although it may need more than two segments fusion.

Benefits of Fixing 3 Proximal Vertebral Bodies vs. 2 in the Treatment of Early-Onset Scoliosis with Growing Rods

Background The outcomes of early-onset scoliosis (EOS) treated with growing rods in which 6 proximal anchor points on 3 vertebrae were used vs. 4 proximal anchor points on 2 vertebra were compared. Methods The records of patients with EOS treated surgically from January 2016 to December 2017 were retrospectively reviewed. In the Proximal 4 group, 2 vertebral bodies were anchored proximally with 4 anchor points; in the Proximal 6 group, 3 vertebral bodies were anchored proximally with 6 anchor points. Results Forty-two patients (mean age 5.11 ± 1.93 years) were included; 22 Proximal 4 group, 20 Proximal 6 group. Mean follow-up was 40.86 ± 13.49 months. The decrease in main curve Cobb angle postoperatively was significantly greater in the Proximal 6 group (33.22° vs. 19.08°) (P < 0.05). Cobb thoracic kyphosis (TK) was significantly decreased postoperatively in the Proximal 6 group (mean 20.70°); no significant decrease occurred in the Proximal 4 group. The main curve Cobb angle decrease at last follow-up was significantly greater in the Proximal 6 group (37.84° vs. 24.23°) (P < 0.05). Cobb TK was significantly decreased at last follow-up in the Proximal 6 group (mean 25.17°, P < 0.05); no significant decrease occurred in the Proximal 4 group. Instrument complications were lower in the Proximal 6 group (15.00% vs. 45.45%) (P < 0.05). No proximal junctional kyphosis was noted. Conclusion Fixing 3 proximal vertebral bodies with 6 anchors improves outcomes of EOS treated with growing rods, and has a lower rate of instrument-related complications.

3D Printed Templates Improve the Accuracy and Safety of Pedicle Screw Placement in the Treatment of Pediatric Congenital Scoliosis

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.