Rib-vertebral Angle Research Articles

THORAX AND IDIOPATHIC SCOLIOSIS

This review is related to the role of thorax in scoliogenesis. The embryology, the prenatal and the postnatal growth of the rib cage of (RC) and the lungs are briefly described. The development of normal RC, the frontal and sagittal diameters of it, the values of mid-thoracic diameters, the thoracic index, the biomechanical contribution of the RC to thoracic stability, the increase in frontal and sagittal thoracic diameter during breathing are defined. The infancy, childhood, puberty (ICP) model of growth is used in both the segmental thoracic ratios (TR) and the Segmental Rib-vertebra angles (RVA) in order to assess the normal and deformed RC in Early Onset (EOS) and Late Onset Scoliosis (LOS). The neuromuscular mechanisms as possible factors causing age-related RVAs changes are discussed. Then the posterior truncal/thoracic asymmetries are reviewed related to school scoliosis screening (SSS) referrals. Next, the development of RC is analyzed in resolving and progressive infantile idiopathic scoliosis (IIS), and in adolescent idiopathic scoliosis (AIS). The menarche and laterality of thoracic scoliotic curves, congenitally fused ribs and pulmonary function in children with idiopathic scoliosis (IS) is also discussed. The pathogenesis of IS according to the Nottingham concept and RC, the thorax and pelvis complex during gait and rotational inertia, the Double Rib Contour Sign (DRCS) and Rib Index (RI), the effect of growth on the relationship of spinal and thoracic deformity are explained. The postoperative fate of IS hump deformity in relation to the RI and the aetiological implications for IS are then stated. The role of the rib-sternum complex is mentioned. John Sevastiks thoracospinal concept of aetiopathogenesis of AIS and his research about IS are described, namely experiments on ribs, correction of experimentally produced scoliosis, suggested surgical intervention on the ribs, experiments on nerves, vascular changes in the chest wall after unilateral resection of the intercostal nerves, and breast asymmetries in female suffering AIS. A biomechanical model using different Cobb angle and rib hump (RH) correction is mentioned. The issue of thoracic kyphosis and hypokyphosis and the impact of the lateral spinal profile (LSP), that is the sagittal plane, is discussed. Finally, IS and evolution of thoracic shape as a scar of evolution are pointed out.

Influence of Paraspinal Growth-Friendly Spinal Implants in Children with Spinal Muscular Atrophy on Parasol Deformity, Rib-Vertebral Angles, Thoracic, and Lung Volumes

Introduction: Children with spinal muscular atrophy (SMA) and progressive neuromuscular scoliosis often require early growth-friendly spinal implant (GFSI) treatment for deformity correction with implant fixation either through pedicle screws or bilateral to the spine using ribto pelvis fixation. It has been proposed that the latter fixation may change the collapsing parasol deformity via changes in the rib-vertebral angle (RVA) with a positive effect on thoracic and lung volume. The purpose of this study was to analyze the effect of paraspinal GFSI with bilateral rib-to-pelvis fixation on the parasol deformity, RVA, thoracic, and lung volumes. Methods: SMA children with (n = 19) and without (n = 18) GFSI treatment were included. Last follow-up was before definite spinal fusion at puberty. Scoliosis and kyphosis angles, parasol deformity, and index, as well as convex and concave RVA, were measured on radiographs, whereas computed tomography images were used to reconstruct thoracic and lung volumes. Results: In all SMA children (n = 37; with or without GFSI), convex RVA was smaller than concave values at all times. GFSI did not crucially influence the RVA over the 4.6-year follow-up period. Comparing age- and disease-matched adolescents with and without prior GFSI, no effect of GFSI treatment could be detected on either RVA, thoracic, or lung volumes. Parasol deformity progressed over time despite GFSI. Conclusion: Despite different expectations, implantation of GFSI with bilateral rib-to-pelvis fixation did not positively influence parasol deformity, RVA and/or thoracic, and lung volumes in SMA children with spinal deformity directly and over time.

Postoperative changes in rib cage deviation in adolescent idiopathic scoliosis.

Scoliosis causes changes in the thorax, but it is unclear what type of changes occur in the thoracic profile after scoliosis surgery. To investigate changes in rib cage deviation in the postoperative period after adolescent idiopathic scoliosis (AIS) surgery. Forty-four patients with AIS with a main right thoracic curvature underwent posterior surgical fusion (PSF), and radiological parameters of the spine and thorax were evaluated. The correction rates of main thoracic curve (MT)-Cobb angle at immediate after surgery and postoperative follow-up (2 years) were 64% and 66%, respectively. At these two postoperative time points, the correction rates of height of thoracic vertebrae 1 to 12 (T1T12) were 10% and 12%; the correction rates of Rib-vertebra angle difference (RVAD) were 59% and 52%; the correction rates of Apical rib hump prominence (RH) were 58% and 76%; while the correction rates of Apical vertebral body-rib ratio (AVB-R) were 23% and 25%, respectively. Statistical analysis showed that all these radiological parameters at the two postoperative time points were significantly different from the preoperative values (p< 0.001). There were significant correlations between MT-Cobb angle and T1-T12 height (p< 0.001), RVAD (p< 0.001), RH (p< 0.001), and AVB-R (p< 0.001). Posterior spinal fusion appears to be effective at correcting scoliosis, and the correction of rib cage deviation also plays an important role.

Curve type, flexibility, correction, and rotation are predictors of curve progression in patients with adolescent idiopathic scoliosis undergoing conservative treatment : a systematic review.

AimsThe aim of this study was to review the current evidence surrounding curve type and morphology on curve progression risk in adolescent idiopathic scoliosis (AIS).MethodsA comprehensive search was conducted by two independent reviewers on PubMed, Embase, Medline, and Web of Science to obtain all published information on morphological predictors of AIS progression. Search items included ‘adolescent idiopathic scoliosis’, ‘progression’, and ‘imaging’. The inclusion and exclusion criteria were carefully defined. Risk of bias of studies was assessed with the Quality in Prognostic Studies tool, and level of evidence for each predictor was rated with the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. In all, 6,286 publications were identified with 3,598 being subjected to secondary scrutiny. Ultimately, 26 publications (25 datasets) were included in this review.ResultsFor unbraced patients, high and moderate evidence was found for Cobb angle and curve type as predictors, respectively. Initial Cobb angle > 25° and thoracic curves were predictive of curve progression. For braced patients, flexibility < 28% and limited in-brace correction were factors predictive of progression with high and moderate evidence, respectively. Thoracic curves, high apical vertebral rotation, large rib vertebra angle difference, small rib vertebra angle on the convex side, and low pelvic tilt had weak evidence as predictors of curve progression.ConclusionFor curve progression, strong and consistent evidence is found for Cobb angle, curve type, flexibility, and correction rate. Cobb angle > 25° and flexibility < 28% are found to be important thresholds to guide clinical prognostication. Despite the low evidence, apical vertebral rotation, rib morphology, and pelvic tilt may be promising factors.Cite this article: Bone Joint J 2022;104-B(4):424–432.

Could screw/hook insertion at the apical vertebrae with rib head dislocation effectively retract the corresponding rib head from spinal canal in dystrophic scoliosis secondary to type 1 neurofibromatosis?

BackgroundRib head dislocation (RHD) in dystrophic scoliosis of type 1 neurofibromatosis (DS-NF1) is a unique disorder caused by skeletal dystrophy and scoliotic instability. No particular surgical manipulation is mentioned in the literature to instruct the spine surgeons to effectively obtain more migration of the dislocated rib head without resection. The present study aimed to investigate the effectiveness of screw/hook insertion at vertebrae with RHDs on the retraction of penetrated rib head from spinal canal.Methods37 neurologically intact patients with DS-NF1 and concomitant 53 RHDs undergoing scoliosis surgery without rib head excision were retrospectively reviewed. We used pre and postoperative whole-spine radiographs to determine the Cobb angle and the vertebral translation (VT), and the CT scans to evaluate the intraspinal rib length (IRL) and rib-vertebral angle (RVA). The dislocated ribs were assigned into two groups according to the presence of screw/hook insertion at vertebrae with RHD: screw/hook group and non-screw/hook group.Results37 dislocated ribs with screws/hooks insertion at corresponding vertebrae were assigned into the screw/hook group and the remaining 16 dislocated ribs consisted of the non-screw/hook group. In the screw/hook group, the correction rates of Cobb angle and VT were significantly higher than the non-screw/hook group after surgery (58.7 ± 16.0% vs. 30.9 ± 12.4%, p = 0.003; 61.8 ± 18.8% vs. 35.1 ± 16.6%, p = 0.001; respectively). Similarly, more correction rates of IRL and RVA were found in the screw/hook group than the non-screw/hook group (63.1 ± 31.3% vs. 30.1 ± 20.7%, p = 0.008; 17.6 ± 9.7% vs. 7.2 ± 3.6%, p = 0.006; respectively). Multiple linear regression analysis revealed that the correction rates of Cobb angle, VT and RVA contributed significantly to correction of IRL (β = 0.389, 0.939 and 1.869, respectively; p = 0.019, 0.001 and 0.002, respectively).ConclusionScrew/hook insertion at dystrophic vertebrae with RHDs contributed significantly to the degree of retraction of penetrated rib head from spinal canal. This effectiveness is mediated by more corrections of VT and RVA.

Factors affecting postoperative pulmonary function deterioration in adolescent idiopathic scoliosis: A prospective study using 3-dimensional image reconstruction by biplanar stereoradiography

This study aimed both to evaluate rib cage parameters in patients with adolescent idiopathic scoliosis (AIS) by three-dimensional (3D) image reconstruction using biplanar stereoradiography (EOS) (EOS Imaging, Paris, France) and identify factors associated with postoperative pulmonary function deterioration (PFD). A total of 67 patients with Lenke type 1 or 2 AIS (59 females and 8 males; mean age, 14.4 years) undergoing posterior corrective fusion with a rod rotation maneuver based on segmental pedicle screw fixation were recruited. 3D images and pulmonary function test results were analyzed preoperatively and at 2 years postoperatively. The following parameters were measured: maximum thickness, maximum width, thoracic index, rib hump, rib cage volume (RCV), spinal penetration index (SPI), endothoracic hump ratio (EHR), vertebra-sternum angle (VSA), rib-vertebra angle difference, vertebral lateral decentering (VLD), forced vital capacity (FVC), and percent predicted FVC (%FVC). PFD was defined as a postoperative %FVC decline of 5% or greater. Patients were divided into two groups, namely PFD and non-PFD. FVC increased from 2.62 L to 2.73 L, while %FVC decreased from 88.7% to 82.7%. The maximum width diminished postoperatively in the PFD group. Patients in the PFD group exhibited a significantly smaller increase in RCV and VLD as well as a significantly smaller decrease in SPI, EHR, and VSA than those in the non-PFD group. The rib cage parameters quantified on 3D images reconstructed using EOS are useful in identifying factors affecting PFD in patients with AIS.

Treatment of infantile idiopathic scoliosis using a novel thoracolumbosacral orthosis: a case report

BackgroundThe recommended treatment for mild to moderate infantile idiopathic scoliosis curves involves serial casting. There are concerns, however, regarding the safety of repeated casting in very young children owing to the requirement for anesthetization during the casting process. Very little research has been conducted on the influence of bracing as an initial treatment for scoliosis in this age group. This report details the successful treatment of a large thoracic curve using a thoracolumbosacral orthosis in an infant diagnosed with infantile idiopathic scoliosis.Case presentationThe Dutch-Australian patient presented at 11 weeks of age with a 44° thoracic scoliosis and a rib vertebral angle difference of 14°. The history and physical examination failed to reveal a cause of the curvature, and a diagnosis of infantile idiopathic scoliosis was made. The patient was prescribed a thoracolumbosacral orthosis (ScoliBrace) to be worn on a part-time basis for a period of 8 months. At the end of the bracing program, the patient’s curve had been reduced to 7° and a rib–vertebral angle difference of 0°. A final follow-up of the patient at 2 years after the cessation of treatment revealed no evidence of scoliosis. The parents were compliant with the bracing protocol and reported that the treatment was tolerated by the infant.ConclusionThe use of an orthosis as a standalone treatment in this patient resulted in significant reduction in a large thoracic scoliosis. Based on the results witnessed in this patient, further investigation into bracing as an alternative to casting is warranted.

Elongation-Derotation-Flexion Casting Treatment of Early-Onset Progressive Scoliosis in Skeletal Dysplasia.

Early-onset scoliosis in children with skeletal dysplasia is progressive, contributing to cardiopulmonary restrictive disease. Serial elongation-derotation-flexion (EDF) casting, used in other etiologies of scoliosis to delay curve progression, may be beneficial in maximizing spine growth. Our hypothesis is serial EDF casting can be safely used as a temporary alternative to surgery, delaying progression and preserving growth, to treat scoliosis in skeletal dysplasia. All patients with skeletal dysplasia treated at a single institution with serial EDF casting for scoliosis were reviewed retrospectively. Radiographic parameters: Cobb angle of major and minor curves, curve location, thoracic height, thoracolumbar height, space available for lung, and rib vertebra angle difference were measured before casting (C1), in first casting (C2), in last casting (C3), and out of last casting (C4). Peak inspiratory pressure (PIP) values were monitored and recorded during the casting application. Eleven patients met the inclusion criteria (mean 9.7 castings). The mean duration of EDF serial casting was 35 months. The mean major Cobb angles were 54 degrees° (C1), 30 degrees (C2), 37 degrees (C3), and 49 degrees (C4) with no statistically significant differences. The mean minor Cobb angles were 35 degrees (C1), 25 degrees (C2), 33 degrees (C3), and 51 degrees (C4) with no statistically significant differences. The mean thoracic heights were 130 mm (C1), 155 mm (C2), 173 mm (C3), and 160 mm (C4). The 19-mm mean difference between C2 and C3 represents spinal growth. The PIP-1, PIP-2, and PIP-3 mean values were 15, 27, and 18 cmH2O, respectively. Changes in PIP-1 and PIP-2 and PIP-2 and PIP-3 were statistically significant. Serial EDF casting can delay surgical scoliosis correction in children younger than 7 years with a diagnosis of skeletal dysplasia. Our study showed that serial casting controls progression of the major curve and allows longitudinal growth of the spine with possible expansion of lung volume for nearly 3 years. During cast application, PIP increased with molding and traction, and improved until windowing and trimming of the cast. Level IV-retrospective study.

Bracing for infantile scoliosis: no sedation needed.

Mehta casting technique applied under anesthesia is standard treatment for infantile scoliosis (IIS). However, concern has been raised about frequent anesthesia in children less than three years. The development of a customized thoracolumbar sacral orthosis (TLSO) could avoid the risks of Mehta casting. To develop a bracing technique for IIS that achieves patient compliance and scoliosis correction. Nine patients with ISS were offered a custom TLSO as an alternative to Mehta casting. One patient declined due to an insurance issue. No anesthesia was required for measurement or fitting of the TLSO. A temperature sensitive monitor recorded wear time. Brace success was determined by radiographic correction and adherence to prescription of greater than 18 hours per day. Eight patients had brace treatment with mean(range): age 19(12-44) months, curve magnitude 34°(22-44°), rib vertebral angle of greater than 20°with follow-up 17(3-28) months. In brace correction was less than 15 degrees in 6 of 8 patients. Compliance monitor recorded wear: 4 patients ≥ 18 hours, 2 patients 16-18 hours, 1 had 14 hours, and 1 monitor malfunctioned and could not be read. Brace design evolved to maximize ipsilateral abdominal relief away from the lateral apical shift of the design. Foam lining was added to prevent skin irritation through the relief opening. Average number of braces per year =2.2. A customized TLSO can achieve in brace correction comparable to Mehta casting with acceptable compliance and without the need for general anesthesia, while allowing bathing and skin care.

Follow-up of an Elongation Bending Derotation Brace in the treatment of infantile scoliosis.

Since 2013, an elongation bending derotation brace (EBDB) has been developed and applied to EOS in our institution. The goals of the study were: 1) to compare radiographic changes before the use of EBDB (Pre-B), in brace (IB), and after the use of EBDB (Post-B) in a minimal two year follow-up; 2) to determine the compliance with the EBDB. Thirteen children diagnosed with an infantile scoliosis (IS) were retrospectively recruited. Under general anesthesia in the OR, child was placed on a Spica casting table, and the spine was manipulated by stockinet straps. Then 3D child's torso was scanned, the EBDB was designed and manufactured for exact fitting to the torso in the corrected position using CAD/CAM technology.1 Mean age at start of EBDB was 2 years and 6 months. Average follow-up was 36 months. Compliance showed a mean 19 hours per day (14 to 23 hours). Pre-treatment Cobb angle was 40°, in brace 22°, and out of brace 28°(p<0.05). Axial vertebral rotation (AVR) by Nash-Moe method improved from 30% before treatment to 21% in brace and 19% at the end of visit (p<0.05). Kyphosis was significantly increased from 16°(Pre-B) to 32°(Post-B) (P<0.05). However, there was reduction of Rib-vertebral angle difference (RVAD) from 23°(Pre-B) to 11°(Post-B) (P>0.05). A cascade of EBDB effectively corrects and stabilizes the 3D spinal deformities in infantile. Thus the EBDB is considered as a successful modality in the treatment of IS children.

Three-dimensional reconstruction image by biplanar stereoradiography reflects pulmonary functional states in adolescent idiopathic scoliosis

This study investigated whether the rib cage parameters estimated based on reconstructed three-dimensional (3D) images with biplanar stereoradiography reflect pulmonary functional states in adolescent idiopathic scoliosis (AIS) patients. A total of 67 Lenke type 1 or 2 AIS patients (59 females and 8 males, mean age 14.4 years) were enrolled. All patients underwent preoperative pulmonary functional tests (PFT) and biplanar stereoradiography. Vital capacity (VC) and forced vital capacity (FVC) pulmonary functional data were collected. Rib-cage parameters (maximum thickness, maximum width, thoracic index (TI), rib hump (RH), rib-cage volume (RCV), spinal penetration index (SPI), endothoracic hump ratio (EHR), vertebra–sternum angle (VSA), rib vertebral angle difference (RVAD), and vertebral lateral decentering (VLD)) were quantified from 3D images. Patients were divided into two groups: restrictive lung disorder (RLD) (%FVC < 80%) and non-RLD (%FVC ≥ 80%). The maximum width and RCV were significantly correlated with VC (p < 0.0001), and FVC (p < 0.0001). RH, EHR, and VSA were negatively correlated with %FVC (p < 0.01). TI, SPI, and RVAD were not correlated with any pulmonary parameters. The maximum widths of RLD patients were significantly shorter than those of the non-RLD patients (218.3 mm vs. 229.7 mm, p < 0.01). The RCV of RLD patients was significantly smaller than that of the non-RLD patients (3.94 L vs. 4.49 L, p < 0.0001). The maximum width and RCV measured by 3D images with biplanar stereoradiography reflected pulmonary functional variables in patients with AIS.

An articulated spine and ribcage kinematic model for simulation of scoliosis deformities

Musculoskeletal multibody modeling can offer valuable insight into aetiopathogenesis behind adolescent idiopathic scoliosis, which has remained unclear. However, the underlying model should represent anatomical joints with compatible kinematic constraints while allowing the model to attain scoliotic postures. This work presents an improved and kinematically determinate model including the whole spine and ribcage, which can attain typical scoliosis deformations of the thorax with compatible constraint strategy and simulate the interaction between all the bony segments of the ribcage and the spine. In the model, costovertebral/costotransverse joints were defined as universal joints based on reported anatomical studies. Articulations between ribs and the sternum were defined as spherical joints except in the ninth and tenth pairs, which have one additional anteroposterior degree-of-freedom. The model is controlled by 15 kinematic parameters, including spinal rhythms and parameters relating to clinical metrics of scoliosis. These input values were measured from the bi-planar radiographs of a 17-year-old scoliosis patient with a right main thoracic curve of 33° Cobb angle. Dependent kinematic variables with clinical relevance were selected for validation purposes and compared with measurements from radiographs. The average errors of rib-vertebra angles, rib-vertebra angle differences, and rib humps were 6.6° and 9.0°, and 6.3 mm. The model appeared to reproduce the spine and rib deformation pattern conforming to radiographs, results in simulating the rib prominence, rib spread, rib-vertebra angles, and sternum orientation, therefore supporting the constraint definitions. The model can subsequently be used to investigate the kinetics of scoliosis and contribute to uncovering the pathomechanism.

Long-term follow-up of patients with infantile idiopathic scoliosis: is the rib vertebra angle difference (RVAD) a reliable indicator of evolution?

Since its original description by Mehta, the rib vertebra angle difference (RVAD) and, in particular, a threshold of 20° have become an accepted and widely utilised prognostic indicator in the assessment of patients presenting with an infantile idiopathic scoliosis (IIS). However, uncertainty in the utility of the RVAD in the prognosis of IIS remains. The aims of this study were to investigate the prognostic significance of the RVAD and to describe the changes in RVAD over long-term follow-up of patients with progressive and resolving IIS. This was a retrospective analysis of patients presenting with IIS at a tertiary spinal deformity unit in the UK. Serial patient radiographs were reviewed and a logistic regression model using the patients index RVAD was created to predict the likelihood of curve progression. At both index presentation and over long-term follow-up, patients with a progressive curve had significantly greater mean Cobb angle and RVAD measurements than those with resolving curves. The RVAD and Cobb were found to correlate positively in both groups, reflecting the underlying costovertebral pathoanatomy. The logistic regression model demonstrated that the optimal RVAD threshold in predicting IIS progression was lower at 17.1° than the 20° cut-off previously advocated. This study describes the utility of the RVAD in predicting IIS evolution. From this analysis, we would advise caution in predicting outcomes based on the index RVAD at presentation. II.

Role of Body Cast Application for Scoliosis Associated With Prader-Willi Syndrome.

Prader-Willi syndrome (PWS) is a rare genetic syndrome, with a prevalence of infantile scoliosis of ~23%. These curves are likely related to severe hypotonia. Approximately 15% of children with PWS will need surgical intervention for their scoliosis. The purpose of this study was to evaluate the effectiveness of curing or controlling moderate and severe infantile scoliosis curves in children with PWS. This single institution, retrospective study of patients with PWS and infantile scoliosis reviewed 34 consecutive children with >24 months follow-up from initiation of serial spinal casting. Cobb angle comparison measurements of radiographs taken precasting, during treatment, and at follow-up were performed. Rib-vertebral angle difference, Nash-Moe rotation, and space available for lung measurements were followed. Outcomes were stratified as "Cured," "Braced," and "Surgery." Average age for first cast for the entire study was 32 months (range, 14 to 64), undergoing 8 casts (range, 3 to 18) over 25 months (range, 9 to 57) for an initial curve of 54 degrees (range, 27 to 106 degrees), which improved to 27 degrees (range, 11 to 78 degrees). In total, 12 patients (35%) were in the Cured group, following 6 casts over 17 months, with an initial curve of 44±14 degrees improving to 17±5 degrees at the end of treatment, and 20±18 degrees at 68-month follow-up. In total, 18 patients were in the Braced group, with curves initially improving from 55±14 degrees to 35±14 degrees, but at 47±20 degrees at 51-month follow-up. Four patients needed surgery, with initial curves 85 degrees (range, 54 to 106 degrees), but surgery could be postponed 56 months (range, 40 to 73) by casting. Rib-vertebral angle difference was not prognostic. Serial spinal casting is effective in for treating infantile scoliosis in children with PWS. One third of patients had their curve resolved, at least temporarily, where they were braced and cast free. The others were able to delay surgery for a number of years. Initial curves <50 degrees in children <3 years of age seem to have the best prognosis. Level IV.

Three-Dimensional Analysis of Preoperative and Postoperative Rib Cage Parameters by Simultaneous Biplanar Radiographic Scanning Technique in Adolescent Idiopathic Scoliosis: Minimum 2-Year Follow-Up.

Prospective study. This study aimed to investigate the changes in rib cage deformity in adolescent idiopathic scoliosis (AIS) by comparing the preoperative and postoperative three-dimensional (3D) reconstruction images using simultaneous biplanar radiographic scanning technique (EOS) (EOS Imaging, Paris, France). EOS data are limited for the analyses of preoperative and postoperative rib cage deformity. A total of 67 Lenke type 1 or 2 AIS patients who underwent surgery (59 females and 8 males) were enrolled in this study. The mean patient age was 14.4 years (range: 11-17 yr). In all patients, posterior corrective fusion was performed with a rod rotation maneuver based on segmental pedicle fixation. Spinal parameters (scoliosis and kyphosis) and rib cage parameters (max thickness, thoracic index (TI), rib hump (RH), surface spinal penetration index (sSPI), end thoracic hump ratio, vertebra-sternum angle, rib vertebral angle difference at the apex, and vertebral lateral decentering), were measured. 3D images were assessed preoperatively and postoperatively at 2-year follow-up. Both main thoracic (MT) and proximal thoracic scoliosis were significantly corrected (51° to 15°, 30° to 17°, P < 0.0001). The rotation of MT apical vertebrae was also significantly corrected (12° to 5°, P < 0.0001). Thoracic kyphosis (T4-T12) significantly increased (13° to 18°, P < 0.0001). Besides, max thickness, TI, and RH demonstrated significant differences between preoperative and postoperative images (P < 0.01). T8-10 sSPI and end thoracic hump ratio decreased significantly postoperatively (P < 0.05). Although surgery significantly decreased vertebra-sternum angle (P < 0.0001), no significant difference was observed between the preoperative and postoperative rib vertebral angle difference (P = 0.32). Following the surgery, vertebral lateral decentering and rib cage volume were significantly increased (P < 0.0001). 3D reconstruction of the rib cage using biplanar standing stereoradiography is useful to evaluate preoperative and postoperative rib cage deformity in patients with AIS.Level of Evidence: 2.

Serial Casting in Neuromuscular and Syndromic Early-onset Scoliosis (EOS) Can Delay Surgery Over 2 Years.

The primary goal in managing early-onset scoliosis (EOS) is delaying/preventing surgical intervention while allowing improved spinal growth and chest wall and lung development to improve life expectancy. The effectiveness of serial casting for patients with neuromuscular and syndromic EOS is unclear. Patients from 2 multicenter registries who underwent serial casting for nonidiopathic scoliosis (NIS) were reviewed retrospectively. Comparisons were made between precasting and postcasting major and compensatory curves and spine height. The need for surgical intervention and any treatment complications were documented. Risk factors for major curve progression from baseline to casting cessation were evaluated via univariate analysis. Forty-four patients (23 females; 21 males) with NIS (26 syndromic, 18 neuromuscular) and a mean age of 3.2 years at baseline were included. Mean follow-up and casting duration was 3.9 and 2.0 years, respectively. There were no statistically significant differences between mean precasting and postcasting major curve (55 vs. 60 degrees; P=0.348), minor curve (31 vs. 33 degrees; P=0.510), or rib-vertebra angle difference (18 vs. 29 degrees; P=0.840). However, thoracic height (15.5 vs. 16.8 cm; P=0.031) and lumbar height (8.9 vs. 9.8 cm; P=0.013) were significantly greater upon casting cessation. Currently, 13 patients (30%) have had successful casting (improvement of major curve ≥10 degrees) while 24 patients (55%) experienced major curve progression (worsening), and 19 patients (43%) required surgical intervention. Mean time from first casting to surgery was 34.5±15.1 months. There were no statistically significant predictors for major curve progression on univariate analysis. Spinal deformity progression despite casting and the subsequent need for surgical intervention for NIS were significantly higher compared with those reported for idiopathic EOS. However, serial casting did afford a substantial delay in surgical intervention. Ultimately, serial casting for neuromuscular or syndromic EOS is an effective strategy for delaying surgical intervention, despite suboptimal radiographic outcomes. Level III.

Accuracy of rib cage parameters from 3-Dimensional reconstruction images obtained using simultaneous biplanar radiographic scanning technique in adolescent idiopathic scoliosis: Comparison with conventional computed tomography

Simultaneous biplanar radiographic scanning technique (EOS) (EOS Imaging, Paris, France) variability has previously been evaluated for spinal parameters, however limited EOS data exist regarding accuracy of 3-dimensional (3D) rib cage reconstruction. The purpose of this study was to compare the evaluation of ribcage parameter between EOS 3D images and 3D computed tomography (CT) images from adolescent idiopathic scoliosis (AIS) patients, and validate the accuracy of EOS 3D ribcage reconstruction images. In total, 31 AIS patients (27 females, 4 males; mean age 14.4 years) with Lenke types 1 or 2 who underwent corrective surgery were enrolled. EOS 3D images were assessed preoperatively for all patients. Rib cage parameters were measured, including surface spinal penetration index (sSPI), endothoracic hump ratio (EHR), vertebra-sternum angle (VSA), rib-vertebral angle difference (RVAD) at apex and vertebral lateral decentering (VLD). Measurements were subsequently compared with CT images. No significant differences were observed in sSPI or EHR measurements between EOS and CT images. Measured VSA values from EOS and CT were −28.1 degrees and −26.1 degrees, respectively. Measured RVAD values from EOS and CT were 13.0 degrees and 12.0 degrees, respectively. No significant differences were observed for measured VSA or RVAD values between EOS and CT images. Measured VLD values from EOS and CT were 68.5% and 67.5%, respectively, representing similar values. The accuracy of rib cage parameters measured with EOS software is similar to the measurements obtained with CT. The results of this study provide surgeons with important evidence pertaining to this novel imaging technology.

Serial casting in early onset scoliosis: syndromic scoliosis is no contraindication

BackgroundSerial casting is a treatment for early onset scoliosis (EOS) in young children to achieve curve correction before bracing or to postpone initial surgical treatment until the patient is older. Good results have been reported for patients with idiopathic early onset scoliosis (IS). However, there are few reports of results in non-idiopathic cases, and the benefits of non-surgical methods in the syndromic-associated early onset scoliosis subgroup are unknown.MethodsRetrospective single-institution study of patient charts and X-rays of all cases of sustained serial casting for EOS.Staged correction was obtained by applying three consecutive casts under general anaesthesia. These were changed every 4 weeks, followed by the implementation of a custom-made full-time Chêneau brace. Correction was measured by Cobb angle (CA) and rib-vertebra angle difference (RVAD) on whole spine anterior-posterior radiographs. Statistical analysis was performed via ANOVA.ResultsThe study group consisted of 6 patiens with IS and 10 with non-idiopathic scoliosis (NIS) – exclusively syndromic-associated. The mean age at onset of treatment was 35 months (±15). The mean follow up was 21 months (±15). In IS patients average CA/RVAD before treatment was 46°(±8)/20°(±12). In NIS patients average CA/RVAD before treatment was 55°(±15)/24°(±14). After application of the third cast, the CA/RVAD was reduced to 20°(±11)/11°(±10) in IS patients. Whereas in NIS patients average CA/RVAD after the thrid cast was 28°(±12)/18°(±13). At latest follow-up the CA/RVAD was 16°(±7)/9°(±8) in IS patients and 31°(±11)/17° (±15) in NIS patients.ConclusionSyndromic etiology is not a contraindication for serial casting in EOS. Our results show a curve correction, measured in CA, of 65% in IS patients and 44% in NIS patients. Significant reduction in the morphologic deformity, measured in RVAD, was achieved in the IS cohort, but not in the NIS cohort. In all cases surgical treatment could be delayed.

Factors That Influence In-Brace Correction in Patients with Adolescent Idiopathic Scoliosis

To identify the factors affecting in-brace correction in patients with adolescent idiopathic scoliosis (AIS). We performed a retrospective analysis of patients with AIS receiving Gensingen brace treatment in our scoliosis center from July 2015 to October 2017 was performed. The selection of patients was in accordance with the Scoliosis Research Society inclusion criteria for a bracing study. Some radiographic and clinical parameters, including the Cobb angle, rib-vertebra angle difference, coronal and sagittal balance, lumbar-pelvic relationship (LPR), Risser sign, curve type, age, gender, height, weight, body mass index, and menstrual status were collected. The correlation and difference analyses were performed to identify the factors influencing in-brace correction. A cohort of 112 patients with AIS (94 girls and 18 boys) were included in the present study. The mean in-brace correction was 59.29% ± 22.33% (range, 16.22%-100.00%). In-brace correction showed a significantly negative correlation with the major curve Cobb angle, minor curve Cobb angle, total curve Cobb angle, and LPR (P< 0.05 for all). Sagittal and coronal imbalance could reduce the curve correction (P < 0.001 and P= 0.008, respectively). The remaining parameters were not related to in-brace correction. In-brace correction in the present study was 59.29% ± 22.33% (range, 16.22%-100.00%). Some factors, including the Cobb angle, sagittal and coronal balance, and LPR, have an effect on in-brace correction. The results from the present study can provide some useful information for brace design and fabrication.

Survey to describe variability in early onset scoliosis cast practices.

PurposeTo investigate paediatric orthopaedists’ cast practices for early onset scoliosis regarding patient selection, cast application, radiographic evaluation, treatment cessation and adjunctive bracing.MethodsA casting survey was distributed to all paediatric orthopaedists in Children’s Spine and Growing Spine Study Groups (n = 92). Questions included physician and patient characteristics, technique, treatment, outcomes, radiographic measurements and comparison to other treatments. A total of 55 orthopaedists (60%) responded, and descriptive statistics were calculated on the subset who cast (n = 45).ResultsA majority of respondents use cast treatment for idiopathic and syndromic scoliosis patients, but not for neuromuscular or congenital scoliosis patients. Major curve angle ranked most important in orthopaedists’ decision to commence cast treatment, in comparison with rib-vertebra angle difference or clinical observations. The major curve angle threshold to initiate casting was a median of 30° (20° to 70°), and the minimum patient age was median ten months (3 to 24). First in-cast and out-of-cast radiographs are taken standing, supine, awake, under anesthesia and/or in traction. In all, 58% consistently cast over or under the arm, while 44% vary position by patient. Respondents were divided about the use of a brace after cast treatment: 22% do not prescribe a brace, 31% always do and 36% do in some patients.ConclusionsFuture multicentre research studies must standardize radiographic practices and consider age and major curve angle at cast initiation and termination, scoliosis aetiology, shoulder position and treatment duration. Practices need to be aligned or compared in these areas in order to distinguish what makes for the best cast treatment possible.Level of EvidenceV, Expert opinion