Scoliosis Model Research Articles

SCO-Spondin Defects and Neuroinflammation Are Conserved Mechanisms Driving Spinal Deformity across Genetic Models of Idiopathic Scoliosis

Adolescent idiopathic scoliosis (AIS) affects 3% to 4% of children between the ages of 11 and 18 [1, 2]. This disorder, characterized by abnormal three-dimensional spinal curvatures that typically develop during periods of rapid growth, occurs in the absence of congenital vertebral malformations or neuromuscular defects [1]. Genetic heterogeneity [3] and a historical lack of appropriate animal models [4] have confounded basic understanding of AIS biology; thus, treatment options remain limited [5, 6]. Recently, genetic studies using zebrafish have linked idiopathic-like scoliosis to irregularities in motile cilia-mediated cerebrospinal fluid flow [7-9]. However, because loss of cilia motility in human primary ciliary dyskinesia patients is not fully associated with scoliosis [10, 11], other pathogenic mechanisms remain to be determined. Here, we demonstrate that zebrafish scospondin (sspo) mutants develop late-onset idiopathic-like spinal curvatures in the absence of obvious cilia motility defects. Sspo is a large secreted glycoprotein functionally associated with the subcommissural organ and Reissner's fiber [12]-ancient and enigmatic organs of the brain ventricular system reported to govern cerebrospinal fluid homeostasis [13, 14], neurogenesis [12, 15-18], and embryonic morphogenesis [19]. We demonstrate that irregular deposition of Sspo within brain ventricles is associated with idiopathic-like scoliosis across diverse genetic models. Furthermore, Sspo defects are sufficient to induce oxidative stress and neuroinflammatory responses implicated in AIS pathogenesis [9]. Through screening for chemical suppressors of sspo mutant phenotypes, we also identify potent agents capable of blocking severe juvenile spine deformity. Our work thus defines a new preclinical model of AIS and provides tools to realize novel therapeutic strategies.

Anterior Vertebral Body Growth Modulation: Assessment of the 2-year Predictive Capability of a Patient-specific Finite-element Planning Tool and of the Growth Modulation Biomechanics.

Numerical planning and simulation of immediate and after 2 years growth modulation effects of anterior vertebral body growth modulation (AVBGM). The objective was to evaluate the planning tool predictive capability for immediate, 1-year, and 2-year postoperative correction and biomechanical effect on growth modulation over time. AVBGM is used to treat pediatric scoliotic patients with remaining growth potential. A planning tool based on a finite element model (FEM) of pediatric scoliosis integrating growth was previously developed to simulate AVBGM installation and growth modulation effect. Forty-five patients to be instrumented with AVBGM were recruited. A patient-specific FEM was preoperatively generated using a 3D reconstruction obtained from biplanar radiographs. The FEM was used to assess different instrumentation configurations. The strategy offering the optimal 2-year postoperative correction was selected for surgery. Simulated 3D correction indices, as well as stresses applied on vertebral epiphyseal growth plates, intervertebral discs, and instrumentation, were computed. On average, six configurations per case were tested. Immediate, 1-year, and 2-year postoperative 3D correction indices were predicted within 4° of that of actual results in coronal plane, whereas it was <0.8 cm (±2%) for spinal height. Immediate postoperative correction was of 40%, whereas an additional correction of respectively 13% and 3% occurred at 1- and 2 year postoperative. The convex/concave side computed forces difference at the apical level following AVBGM installation was decreased by 39% on growth plates and 46% on intervertebral discs. This study demonstrates the FEM clinical usefulness to rationalize surgical planning by providing clinically relevant correction predictions. The AVBGM biomechanical effect on growth modulation over time seemed to be maximized during the first year following the installation. 3.

Study of Textile Fabric Materials used in Spinal Braces for Scoliosis

Scoliosis patients are normally treated either by surgery or by wearing spinal braces for correction. A spinal brace may be made of rigid materials or soft materials. The use of soft materials for braces, such as fabric materials, is one alternative being used to develop soft braces because textile materials could be comfortable and provide high compliance with users. However, there are no studies about how to provide treatment/prevention of scoliosis using various textile fabric materials to fabricate a soft brace. Thus, this study aims to study the effect of the physical and mechanical properties of textile fabric materials used in a soft brace for the treatment/prevention of scoliosis using finite element model (FEM) simulation. This study covers the following stages: a) development of a geometric model of scoliosis through finite element modelling using 2D X-ray clinical data; b) selection of appropriate textile materials to be used in a soft brace by measuring physical and mechanical properties; and c) determination of the performance of the soft brace fabricated with various textile fabric materials in terms of the Cobb angle through FEM simulation. The results of this study found that the textile fabric materials made of polyester with sandwich mesh and elastic band in parallel layer provides good softness and air permeability and it has a high capability to provide the treatment of scoliosis in terms of Cobb angle changed by 14.4% using FEM simulation. Such design of soft brace with textile fabric materials provides more comfortable for patients in wearing for long time. It is worthwhile for rehabilitation professionals to design appropriate textile-based soft braces for scoliosis.

Rigid 3D Registration Algorithm for Localization of the Vertebral Centroids in 3D Deformity Models of Adolescent Idiopathic Scoliosis

Computer-Aided Design and Applications is an international journal on the applications of CAD and CAM. It publishes papers in the general domain of CAD plus in emerging fields like bio-CAD, nano-CAD, soft-CAD, garment-CAD, PLM, PDM, CAD data mining, CAD and the internet, CAD education, genetic algorithms and CAD engines. The journal is aimed at all developers and users of CAD technology to ptovide CAD solutions for various stages of design and manufacturing. The journal publishes all about Computer-Aided Design and Computer-Aided technologies.

Induction of a Flexible Idiopathic-like Scoliosis with Axial Rotation Using a Dynamic Torsional Spring System: A Mini-pig Scoliosis Model

Induction of a Flexible Idiopathic-like Scoliosis with Axial Rotation Using a Dynamic Torsional Spring System: A Mini-pig Scoliosis Model

Development and first clinical use of a novel anatomical and biomechanical testing platform for scoliosis.

Previous studies have demonstrated that, by using various three-dimensional (3D) printing technologies, synthetic spine models can be manufactured to mimic a human spine in its gross and radiographic anatomy and the biomechanical performance of bony and ligamentous tissue. These manufacturing processes have not, however, been used in combination to create a long-segment, biomimetic model of a patient with scoliosis. The purpose of this study was to describe the development of a biomimetic scoliosis model and early clinical experience using this model as a surgical planning and education platform. Synthetic spine models were printed to mimic the anatomy and biomechanical performance of 2 adult patients with scoliosis. Preoperatively, the models were surgically corrected by the attending surgeon of each patient. Patients then underwent surgical correction of their spinal deformities. Correction of the models was compared to the surgical correction in the patients. Patient 1 had a preoperative coronal Cobb angle of 40° from L1 to S1, as did the patient's synthetic spine model. The patient's spine model was corrected to 17.6°, and the patient achieved a correction of 17.3°. Patient 2 had a preoperative mid-thoracic Cobb angle of 88° and an upper thoracic Cobb angle of 43°. Preoperatively, the patient's spine model was corrected to 19.5° and 9.2° for the mid-thoracic and upper thoracic curves, respectively. Immediately after surgery, the patient's mid-thoracic and upper thoracic Cobb angles measured 18.7° and 9.5°, respectively. In both cases, the use of the spine models preoperatively changed the attending surgeon's operative plan. A novel synthetic spine model for corrective scoliosis procedures is presented, along with early clinical experience using this model as a surgical planning platform. This model has tremendous potential not only as a surgical planning platform but also as an adjunct to patient consent, surgical education, and biomechanical research.

Video of the attending spine surgeon for patient 1 correcting the patient’s scoliosis model preoperatively

Video of the attending spine surgeon for patient 1 correcting the patient’s scoliosis model preoperatively

Scoliosis induced by costotransversectomy in minipigs model.

Aim To validate surgical costotransversectomy as a technique for creating a scoliosis model in minipigs and to assess whether differences in approach (posterior medial approach, posterior paramedial approach and anterior approach by video-assisted thoracoscopy) lead to differences in the production of spinal deformity. Creation of disease models in experimental animals, specifically in minipigs, is controversial, as no appropriate technique has been reported. Methods Surgical costotransversectomy was performed in 11 minipigs using 3 different approaches: posterior medial approach (4 animals, group I), posterior paramedial approach (3 animals, group II) and anterior approach by videothoracoscopy (4 animals, group III). A conventional x-ray study was performed in the immediate postoperative period. Follow-up lasted for 4 months. Specimens were humanely killed according to current protocols, and a second x-ray study was performed. A deformation was measured using the Cobb angle and direct observation of the rotational component. Results Data from group I revealed a scoliosis deformation of 27º-41º (mean 34.5º) with a macroscopic rotational component. No deformity (<10º) or rotational component was observed in groups II and III. Only a posterior medial costotransversectomy produced a significant deformity in minipigs and established a valid model for studying scoliosis in these animals. Conclusion Only a posterior medial costotransversectomy produces a significant deformity in minipigs and establish a valid model for studying scoliosis in these animals. A tensegrity model would elucidate such results and harmonize disparate conclusions. Further investigation is needed to demonstrate the reliability of tensegrity principles for spinal biomechanics.

SCO-Spondin Defects and Neuroinflammation Identified as Conserved Mechanisms Driving Severe Spine Deformity Across Genetic Models of Idiopathic Scoliosis

Adolescent idiopathic scoliosis (AIS) affects 3-4% of children between the ages of 11 and 18. This disorder, characterized by abnormal three-dimensional spinal curvatures that typically develop during periods of rapid growth, occurs in the absence of congenital vertebral malformations or neuromuscular defects. Genetic heterogeneity and a historical lack of appropriate animal models have confounded basic understanding of AIS biology and, as a result, treatment options remain limited. Recently, genetic studies using zebrafish have linked idiopathic-like scoliosis to irregularities in motile cilia-mediated cerebrospinal fluid (CSF) flow. However, since loss of cilia motility in human primary ciliary dyskinesia patients is not fully associated with scoliosis, other pathogenic mechanisms remain to be determined. Here, we demonstrate that zebrafish scospondin (sspo) mutants develop late onset idiopathic-like spinal curvatures in the absence of obvious cilia motility defects. Sspo is a large secreted glycoprotein functionally associated with the subcommissural organ (SCO) and Reissner’s fiber (RF) – ancient and enigmatic organs of the brain ventricular system reported to govern CSF homeostasis, neurogenesis and embryonic axis development. We demonstrate that irregular localization of Sspo around the SCO and RF is associated with acquired idiopathic scoliosis across diverse genetic models. Furthermore Sspo defects are sufficient to induce oxidative stress and neuroinflammatory responses implicated in AIS pathogenesis. Through screening for chemical suppressors of sspo mutant phenotypes, we also identify potent agents capable of blocking severe juvenile spine deformity. Our work thus defines a new useful model for AIS and provides tools to realize novel therapeutic strategies.

Neuroinflammatory signals drive spinal curve formation in zebrafish models of idiopathic scoliosis.

The etiopathogenesis of idiopathic scoliosis (IS), a highly prevalent spinal deformity that occurs in the absence of obvious congenital or physiological abnormalities, is poorly understood. Although recent zebrafish genetic studies have linked cilia motility and cerebrospinal fluid (CSF) flow defects with scoliosis progression, underlying mechanisms were not identified. Here, we use next-generation sequencing and conditional genetic methodologies to define the spatial and biological origins of spinal curve formation in ptk7 mutant zebrafish, a faithful IS model. We demonstrate that focal activation of proinflammatory signals within the spinal cord is associated with, and sufficient for, induction of spinal curvatures. Furthermore, administration of acetylsalicylic acid (aspirin) or N-acetylcysteine (NAC) to juvenile ptk7 mutants significantly reduces the incidence and/or severity of scoliosis phenotypes. Together, our results implicate neuroinflammation, downstream of CSF defects, in spinal curve formation and provide intriguing evidence that simple immunomodulating therapies might prove effective in managing idiopathic-like spinal deformities.

Minodronate treatment improves low bone mass and reduces progressive thoracic scoliosis in a mouse model of adolescent idiopathic scoliosis.

Recent studies have shown an association between osteopenia and adolescent idiopathic scoliosis (AIS) and implied that osteopenia plays a causative role in AIS development. This study aimed to determine if minodronate (MIN) treatment could prevent curve progression by increasing bone mass in a thoracic restraint (TR) mouse model, which develops causes the development of thoracic scoliosis similar to human AIS. A total of 100 young female C57BL6J mice were divided into four groups: (1) control with vehicle (CON/VEH; n = 20), (2) control with MIN (CON/MIN; n = 20), (3) TR with vehicle (TR/VEH; n = 30), or (4) TR with MIN (TR/MIN; n = 30). MIN (0.01 mg/kg/week) and vehicle were administered intraperitoneally to their respective groups. TR was performed at age 4 weeks, and the mice were sacrificed at age 9 weeks. Body weights, spine radiographs, femoral bone mineral density (BMD), serum bone marker levels, and histomorphometry of the cancellous bone of the thoracic vertebrae were analyzed. TR significantly reduced weight gain in the TR/VEH group relative to the CON/VEH group. TR also induced osteoporosis with accelerated bone resorption, as indicated by decreases in femoral BMDs and thoracic cancellous bone volume and increases in serum bone resorption marker levels and histomorphometric resorption parameters in the TR/VEH group. MIN partially improved body weight gain and improved poor bone structure relative to the TR/VEH group by suppressing high bone resorption in the TR/MIN mice. MIN significantly reduced the curve magnitudes, as indicated by a 43% lower curve magnitude in the TR/MIN mice than in the TR/VEH mice (17.9 ± 8.9° vs. 31.5 ± 13.1°; p< 0.001). The administration of MIN increased bone mass and reduced the severity of scoliosis in the TR mice. MIN was suggested as a possible inhibitor of scoliosis development.

Surgical Planning and Follow-up of Anterior Vertebral Body Growth Modulation in Pediatric Idiopathic Scoliosis Using a Patient-Specific Finite Element Model Integrating Growth Modulation

Study DesignNumerical planning and simulation of immediate and post-two-year growth modulation effects of Anterior Vertebral Body Growth Modulation (AVBGM). ObjectivesTo develop a planning tool based on a patient-specific finite element model (FEM) of pediatric scoliosis integrating growth to computationally assess the 3D biomechanical effects of AVBGM. Summary of Background DataAVBGM is a recently introduced fusionless compression-based approach for pediatric scoliotic patients presenting progressive curves. Surgical planning is mostly empirical, with reported issues including overcorrection (inversion of the side) of the curve and a lack of control on 3D correction. MethodsTwenty pediatric scoliotic patients instrumented with AVBGM were assessed. An osseoligamentous FEM of the spine, rib cage, and pelvis was generated before surgery using the patient′s 3D reconstruction obtained from calibrated biplanar radiographs. For each case, different scenarios of AVBGM and two years of vertebral growth and growth modulation due to gravitational loads and forces from AVBGM were simulated. Simulated correction indices in the coronal, sagittal, and transverse planes for the retained scenario were computed and a posteriori compared to actual patient′s postoperative and two years' follow-up data. ResultsThe simulated immediate postoperative Cobb angles were on average within 3° of that of the actual correction, while it was ±5° for kyphosis/lordosis angles, and ±5° for apical axial rotation. For the simulated 2-year postoperative follow-up, correction results were predicted at ±3° for Cobb angles and ±5° for kyphosis/lordosis angles, ±2% for T1–L5 height, and ±4° for apical axial rotation. ConclusionA numeric model simulating immediate and post-two-year effects of AVBGM enabled to assess different implant configurations to support surgical planning. Level of EvidenceLevel III.

Variational model of scoliosis

Scoliosis, being one of the most widespread spinal diseases among children, has been studied extensively throughout the history of medicine, yet there is no clear understanding of its initiating factors and the mechanogenesis of the monomorphic three-dimensional deformation due to its polyetiological nature. We present a novel mathematical model of the process of emergence of the three-dimensional deformation of the human spine based on variational principles. Typical scoliosis geometry is assumed to be described as minimal curves of a particular energy functional, which are shown to closely resemble actual scoliosis. We investigate the numerical properties of the first stage of scoliosis, which is shown to have the highest influence on the development of the disease.

Validation of a Clinical Prediction Model for the Development of Neuromuscular Scoliosis: A Multinational Study

BackgroundThe objective of this study was to evaluate the performance of a clinical prediction model of neuromuscular scoliosis via external validation. MethodsWe analyzed a series of 120 patients (mean age ± standard deviation, 15.7 ± 1.8 years; range: 12 to 18 years) with cerebral palsy, severe motor disorders, and cognitive impairment with and without neuromuscular scoliosis treated in two specialized units (70 patients from Nice, France, and 50 patients from Lublin, Poland) in a cross-sectional, double-blind study. Data on etiology, diagnosis, functional assessments, type of spasticity, epilepsy, scoliosis, and clinical history were collected prospectively between 2005 and 2015. Fisher's exact test and multiple logistic regressions were used to identify influential factors for developing spinal deformity. Thus, we applied a predictive model based on a logistic regression algorithm to predict the probability of scoliosis onset for new patients. ResultsChildren with truncal tone disorders (P = Multivariate logistic regression highlighted previous hip surgery (P = 0.002 ≈ 0.005), intractable epilepsy (P = 0.01 ≈ 0.04) and female gender (0.07) as influent factors in the two cohorts. Average accuracy, sensitivity, and specificity of the predictive model were 74%. ConclusionsWe validated a prediction model of neuromuscular scoliosis. In cerebral palsy subjects with the previouslymentioned predictors of scoliosis, the frequency of clinical examinations of spine and spinal x-ray should be increased to easily identify candidates for treatment.

Lumbar Scoliosis Induction in Juvenile Dogs by Three-dimensional Modulation of Spinal Growth Using Nickel-Titanium Coil Springs.

Background:Current treatments for scoliosis have some defects and complications. To study spinal deformities and test novel scoliosis treatments, many animal models of scoliosis have been developed. These models applied a single load to the spine and could not precisely modulate the spinal growth in different dimensions. In this study, we applied posterior tethering in various directions with the application of nickel-titanium (NT) coil springs in dog's spine to modulate spinal growth in the coronal, sagittal, and transverse planes and create a scoliosis model possess curves that mimic adolescent idiopathic scoliosis (AIS) three dimensionally.Methods:Scoliosis was surgically induced in eight 8-week-old female dogs (weight: 1.95–2.30 kg) using bone screws and NT coil springs. The deformity was induced through the placement of posterior NT coil springs that tethered the spine by bone screw fixation. All dogs were monitored with serial radiographs to document changes in deformities.Results:All experimental animals developed scoliotic curves convex to the left in the lumbar segment. The mean coronal Cobb angle was 18.0° immediately postoperatively and 54.5° at 22 weeks. The mean lordosis increased from 6.2° postoperatively to 35.0° at final follow-up. Apical axial rotation increased from 4.5° postoperatively to 31.2° at 22 weeks.Conclusions:With the application of NT springs in dogs that allowed posterior tethering in various directions, lumbar spinal deformity was achieved in three planes: coronal, sagittal, and transverse planes. Notably, the lumbar spine in surgically treated dogs developed lordoscoliosis with obvious rotation and the curves mimic AIS three dimensionally well. This method allows lumbar scoliosis to develop without deep dissection of muscle and maintains the essential anatomical elements along the spinal curve. Moreover, the spinal growth modulation technique could yield information that would provide a basis for developing novel early-stage treatments for children with scoliosis.

Effect of Asymmetric Tension on Biomechanics and Metabolism of Vertebral Epiphyseal Plate in a Rodent Model of Scoliosis.

To investigate the effect of asymmetric tension on idiopathic scoliosis (IS) and to understand its pathogenic mechanism. The rodent model of scoliosis was established using Sprague-Dawley rats with left rib-tethering from T6 to T12 , tail and shoulder amputation, and high-cage feeding. Vertebrae epiphyseal cartilage plates were harvested from the convex and concave sides. To analyze differences on the convex and concave sides, finite element analysis was carried out to determine the mechanical stress. Protein expression on epiphyseal cartilage was evaluated by western blot. Micro-CT was taken to evaluate the bone quality of vertebral on both sides. Scoliosis curves presented in X-ray radiographs of the rats. Finite element analysis was carried out on the axial and transverse tension of the spine. Stresses of the convex side were -170.14, -373.18, and -3832.32 MPa (X, Y, and Z axis, respectively), while the concave side showed stresses of 361.99, 605.55, and 3661.95 MPa. Collagen type II, collagen type X, Sox 9, RunX2, VEGF, and aggrecan were expressed significantly more on the convex side (P < 0.05). There was asymmetric expression of protein on the epiphyseal cartilage plate at molecular level. Compared with the convex side, the concave side had significantly lower value in the BV/TV and Tb.N, but higher value in the Tb.Sp (P < 0.05). There was asymmetry of bone quality in micro-architecture. In this study, asymmetric tension contributed to asymmetry in protein expression and bone quality on vertebral epiphyseal plates, ultimately resulting in asymmetry of anatomy. In addition, asymmetry of anatomy aggravated asymmetric tension. It is the first study to show that there is an asymmetrical vicious circle in IS.

Novel porcine experimental model of severe progressive thoracic scoliosis with compensatory curves induced by interpedicular bent rigid temporary tethering.

The tether release model will be used to evaluate corrective non-fusion technologies in future investigations. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:174-182, 2018.

The value of applying a melatonin antagonist (Luzindole) in improving the success rate of the bipedal rat scoliosis model

BackgroundAn ideal animal model has always been the key to research the pathogenesis and treatment of adolescent idiopathic scoliosis (AIS), while available methods have obvious disadvantages. The deficiency of melatonin has been proved relating to AIS. In this research, we intended to apply Luzindole, the melatonin antagonist, in bipedal rat model, for the block of combination of melatonin and its receptor, to inhibit the melatonin effect, and then to understand whether this method can effectively improve the scoliosis rate of bipedal rat model, and investigate the role of melatonin in scoliosis. To investigate the feasibility of improving the success rate of bipedal rat scoliosis model via intraperitoneal injection of melatonin antagonist (Luzindole).MethodsA total of 60 3-weeks-old Sprague-Dawley rats were included in this study, and were divided into 3 groups (A, B and C). Each group included 20 rats. Osteotomy of the bilateral proximal humerus and proximal tailbone was performed in group A and group B; intraperitoneal injection of Luzindole (0.2 mg/kg) was performed in group A and group C. X-rays were taken before the surgery, 1 month after the surgery, 3 months after the surgery, and 6 months after the surgery, to calculate the Cobb’s angle of the spine (>10° was considered scoliosis). The weight of every rat was also measured at the same time. Rats were euthanized 6 months after surgery to determine the calmodulin level in thrombocytes.ResultsThe rate of scoliosis in group A (14/20) was significantly higher than those in group B (6/20) and group C (0/20) (P < 0.05). The differences in the weights of the 3 groups were non-significant; as were differences in the calmodulin level in thrombocytes.ConclusionThe application of the melatonin antagonist of Luzindole can improve the success rate of the bipedal rat scoliosis model. Meanwhile, this study indicates that a decreased melatonin level is not the primary cause of scoliosis, but that it may increase the likelihood and severity of scoliosis.

The Development of a Representative Porcine Early-Onset Scoliosis Model With a Standalone Posterior Spinal Tether

Study DesignIn vivo analysis in a porcine model. ObjectivesTo develop a porcine experimental scoliosis model representative of early-onset scoliosis (EOS) with the use of a radiopaque ultra-high molecular weight polyethylene (UHMWPE) posterior spinal tether. Summary of Background DataLarge animal experimental scoliosis models with substantial growth potential are needed to test new fusionless scoliosis correction techniques. Previously described scoliosis models involve rib procedures, which violate the thoracic cage and affect subsequent corrective procedures. Models omitting these rib procedures have experienced difficulties in producing persistent three-dimensional structural deformities representative of EOS. MethodsScoliosis was induced in 14 immature pigs using an asymmetric posterior radiopaque UHMWPE spinal tether fixated to an offset device at lumbar and thoracic levels. Radiographs were taken at 2-week intervals, and frontal and sagittal Cobb angles were measured. A tether release was performed at the 10-week follow-up, and the animals were observed for another 10 weeks. ResultsFour animals had complications (infections and/or screw breakout) and were excluded from the study. Eight animals developed progressive curves with a mean frontal Cobb angle of 62°. A thoracic lordosis (34°) and a thoracolumbar kyphosis (22°) formed. CT analysis, acquired prior to tether release, showed a mean vertebral rotation of 37° at the apex with a mean vertebral wedge angle of 10°. After tether release, the frontal Cobb angles decreased to 46° at the 20-week follow-up. Sagittal curvature was not substantially affected after tether release. ConclusionsWe describe a large animal scoliosis model, which exhibits a substantial deformity in three planes without the use of rib procedures additional to a posterior spinal tether. The created deformities showed persistence after tether release. With the management of infection and enhancement of instrumentation stability, the creation of a valid model for testing new devices in fusionless scoliosis surgery seems feasible. Level of EvidenceLevel V.

WHAT IS IDIOPATHIC SCOLIOSIS?

The lecture, based on long experience of research, addresses controversial issues in spinal deformity together with some generalizations. The term of scoliosis is defined as a violation of the spine morphogenesis during the early embryonic development, which, in the process of growth, develops into spinal deformity with clinical variants depending on the degree of morphogenesis violation. The etiological factor of scoliosis is ectopic localization of neural crest-derived cells, which are not genetically deterministic to chondrogenesis and the growth process, in the vertebral body growth plates. The local violation of chondrogenesis in the vertebral body growth plates is a cause of the growth asymmetry and spinal deformity development. The variability of structural changes and the progression prediction depend on the degree of violation of morphogenetic processes laid down during embryogenesis. A phenotype of scoliosis is the primary scoliotic or kyphotic deformity of the spine with variants of the disease course depending on its stage. Research Perspective: the creation of an experimental model of scoliosis with clinical variants and the development of preventive correction of the studied pathology.