Adolescent Idiopathic Scoliosis Deformity Research Articles

Patterns of coronal curve changes in forward bending posture: a 3D ultrasound study of adolescent idiopathic scoliosis patients.

The Adam's forward bending test is the most commonly used approach to assess the spine deformity in adolescent idiopathic scoliosis (AIS) patients. However, there are noticeable differences in the hump appearance from standing to forward bending. This phenomenon has yet to be understood due to limitations of conventional radiographs. This study aimed to investigate effects of postural change in the spine deformity in the coronal plane of AIS patients using a 3D ultrasound imaging system. This was a prospective study that recruited 72 AIS patients at a single institute. All patients were scanned twice in the sitting and sitting forward bending postures. A coronal ultrasound image showing the spinal curvature was generated after each scan and the spinous process angle (SPA) representing the deformity was manually measured from it. Correlation of SPAs under sitting and sitting forward bending postures was analyzed. In the comparison test, it was noted that there were three types of spine profile alternation after the postural change. In types I and II, the SPA angle numbers were the same before and after forward bending and only SPA values changed. In type III, the two curvatures were changed to one curvature in the forward bending posture. Moderate correlation was observed between the angles obtained in the two postures (r = 0.55, p < 0.001). Spine deformities of AIS patients vary with different postures. The patterns of changes in sitting and sitting forward bending postures are highly subject dependent. These slides can be retrieved under Electronic Supplementary Material.

Aberrant miR-145-5p/β-catenin signal impairs osteocyte function in adolescent idiopathic scoliosis.

Recently, noncoding RNAs have been thought to play important roles in the sporadic occurrence of spinal deformity of adolescent idiopathic scoliosis (AIS). As a prognostic factor for curve progression, low bone mass has been hypothesized to crosstalk with AIS pathogenesis. Abnormal osteoblasts activities are reported in AIS without a clear mechanism. In this study, bone biopsies from patients with AIS and control subjects and the primary osteoblasts derived from those samples were used to identify the potential microRNA (miRNA) candidates that interfere with osteoblasts and osteocytes function. Microarray analysis identified miRNA-145-5p (miR-145) as a potential upstream regulator. miR-145 and β-catenin mRNA ( CTNNB1) were overexpressed in AIS bone tissues and primary osteoblasts, and their expression correlated positively in AIS. Knockdown of miR-145 restored impaired osteocyte activity through the down-regulation of active β-catenin expression and its transcriptional activity. Significant negative correlations between circulating miR-145 and serum sclerostin, osteopontin, and osteoprotegerin were noted in patients with AIS, which was in line with our cellular findings. This is the first study to demonstrate the effect of aberrant miRNA expression and its effect on osteocyte function in AIS, which may contribute to the low bone mass. Our findings also provide insight into the development of circulating microRNAs as a bone quality biomarker or even a prognostic biomarker for AIS.-Zhang, J., Chen, H., Leung, R. K. K., Choy, K. W., Lam, T. P., Ng, B. K. W., Qiu,Y., Feng, J. Q., Cheng, J. C. Y., Lee, W. Y. W. Aberrant miR-145-5p/β-catenin signal impairs osteocyte function in adolescent idiopathic scoliosis.

Similar coronal curvature may not represent the same 3-dimensional deformity in adolescent idiopathic scoliosis: a matched-pair study using EOS imaging system

Objective: To analyze the preoperative axial plane and the surgical outcomes of the Lenke type 1A patients with adolescent idiopathic scoliosis (AIS) whose coronal curve type was matched but thoracic kyphosis (TK) was different. Methods: This study retrospectively reviewed a series of Lenke type 1A female AIS patients who underwent corrective surgery in the Department of Spine Surgery of Nanjing Drum Tower Hospital from May to August 2017. After matched with the Cobb angle of the main thoracic curve, the apical vertebral, the vertebra number included in the curve, the lumber modifier in the Lenke classification and Risser sign, 12 pairs of AIS patients, whose coronal curve was matched but thoracic kyphosis was different, were included in this study. The patients were divided into normal TK group and thoracic hypokyphosis group. EOS whole-body images were taken preoperatively and reconstructed by three-dimensional reconstruction. The whole spine anteroposterior X-ray was taken at 3 weeks after surgery. The radiographic parameters were measured on the preoperative and postoperative two-dimensional X-ray images: coronal Cobb angle, TK, lumbar lordosis (LL), pelvic incidence (PI) and pelvic tilt (PT). The vertebra rotation was obtained on the EOS three-dimensional reconstructed image, and the average vertebral rotation of the major thoracic curve (MTR), the average vertebral rotation of the proximal thoracic curve (PTR) and the average vertebral rotation of the lumbar curve (LR) were calculated. The paired sample t test was used to compare the difference of preoperative and postoperative radiographic parameters between the groups. Results: A total of 24 patients (12 pairs) were included in this study with an average age of (13.7±2.9) years. The preoperative Cobb angle was similar in the two groups (53.8°±10.2° vs 51.0°±11.1°, t=0.27, P=0.81). The average preoperative TK of the normal TK groups was 28.2°±6.1°, while that of the thoracic hypokyphosis group was 11.2°±5.6°(t=7.68, P<0.01). The MTR in the normal TK group was significantly smaller than that in the thoracic hypokyphosis group (10.2° vs 12.7°, t=-3.74, P<0.01), and there was a significant correlation between TK and MTR (r=0.30, P=0.03). As for the lumbar curve rotation, the LR of the normal TK group was significantly smaller than that in the thoracic hypokyphosis group (t=-2.65, P=0.002), but the absolute value of the two groups was similar (t=-0.33, P=0.31). The lumbar Cobb angle correction rate was significantly greater in patients with thoracic and lumbar curve rotating in the same direction than that in the opposite direction (81.1% vs 61.9%, t=4.24, P=0.005). Conclusions: It indicated that when the coronal deformity is matched, the MTR of the patients with thoracic hypokyphosis is significantly larger than that in the patients with normal thoracic kyphosis. The direction of the thoracic and lumbar curve rotation is required to be well concerned in the preoperative surgical planning.

The effect of deformity correction on psychiatric condition of the adolescent with adolescent idiopathic scoliosis.

The purpose of this prospective study was to evaluate the effects of deformity correction on body image, quality of life, self-esteem, depression and anxiety in patients with adolescent idiopathic scoliosis (AIS) who underwent surgery. Between June 2014 and July 2015, 41 consecutive patients who underwent surgery for AIS were compared with the control group of 52 healthy patients regarding the changes in the pre- and postoperative quality of life and psychiatric status of patients with deformity correction. Body Cathexis Scale (BCS), Pediatric Quality of Life Inventory (PedsQL), Children's Depression Inventory (CDI), Piers-Harris self-esteem questionnaire (PH-SEQ) and state-trait Anxiety Inventory for Children were used to evaluate the patients. There was a significant decrease in postoperative first-year Cobb angle and trunkal shift imbalance compared with the preoperative values (p = 0.0001 and p = 0.0001). Postoperative first-year thoracic kyphosis angle and body height showed a significant increase according to preoperative values (p = 0.0001 and p = 0.0001). Postoperative PH-SEQ score and PedsQL total score showed a significant increase in the study group compared to the preoperative level, but no significant difference was found between the control group. Postoperative CDI score, BCS score, STAI-state and STAI-trait scores decreased significantly in the study group compared with preoperative scores. Surgical correction of deformity in AIS provided significant improvements regarding quality of life and psychiatric condition. Spinal surgeons should be aware of the possible psychological problems of AIS patients and should keep in mind that deformity correction not only improves physical health but also improves mental health. These slides can be retrieved under Electronic Supplementary Material.

Facet joint degeneration in adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) is a poorly understood deformity of the thoracolumbar spine which affects the intervertebral discs (IVDs) and the articular facet joints. The knowledge concerning facet joints in this context is very limited, although facet joint degeneration is a known contributor of back pain. In this study, a comprehensive investigation was performed to characterize the facet joint chondrocytes and extracellular matrix within the scoliotic spine. Surgically removed articular facet joint tissues were collected from patients undergoing spinal corrective surgery for AIS deformities, while non‐scoliotic articular facet joint tissues were obtained from cadaveric organ donors. Alterations in cartilage tissue structure were evaluated histologically with safranin‐O fast green and a modified OARSI grading scale. Pro‐inflammatory cytokines, matrix‐degrading proteases, and fragmented matrix molecules associated with cartilage degradation were analyzed by immunohistochemistry and western blotting. Safranin‐O fast green staining revealed that young scoliotic facet joints show clear signs of degeneration with substantial proteoglycan loss, similar to osteoarthritis (OA). The proteoglycan levels were significantly lower than in healthy asymptomatic non‐scoliotic control individuals. In comparison to controls, scoliotic articular facets showed increased cell density, increased expression of the proliferation marker Ki‐67, and higher expression of MMP‐3, MMP‐13, and IL‐1β. Expression and fragmentation of the small leucine‐rich proteins (SLRPs) chondroadherin, decorin, biglycan, lumican, and fibromodulin were analyzed with western blot. Chondroadherin and decorin were fragmented in cartilage from patients with a curve greater than 70°, whereas biglycan and fibromodulin did not show curve‐related fragmentation. AIS facet joint cartilage shows hallmarks of OA including proteoglycan loss, overexpression of pro‐inflammatory mediators, increased synthesis of matrix‐degrading proteases and fragmentation of SLRPs. As with patients with age‐related OA, the premature joint degeneration seen in scoliotic patients is likely to contribute to the pain perceived in some individuals.

Genetic Variant of GPR126 Gene is Functionally Associated With Adolescent Idiopathic Scoliosis in Chinese Population.

A genetic association study of GPR126 gene with adolescent idiopathic scoliosis (AIS) in the Chinese population. To investigate whether rs9403380, rs6570507, and rs7774095 of GPR126 gene are susceptible locus of AIS and to further determine the functional variants regulating gene expression in tissues of AIS. Previous studies have identified several new susceptibility locus for AIS in GPR126 gene. No studies have, however, investigated GPR126 expression in tissues of AIS, and the regulatory role of susceptible variants in the gene expression remains obscure. Rs9403380, rs6570507, and rs7774095 were genotyped in 1956 patients with AIS and 2094 controls. The differences of genotype and allele distributions between patients and controls were calculated using chi-square test. Paravertebral muscles were collected from 67 patients with AIS, 20 patients with congenital scoliosis, and 20 patients with lumbar disc herniation. Vertebral bones were obtained in eight patients with AIS and five patients with lumbar disc herniation. Patients with AIS were classified into three groups according to the genotypes of each single-nucleotide polymorphism, and one-way analysis of variance test was used to compare GPR126 expression among different groups and genotypes. All the three single-nucleotide polymorphisms were found significantly associated with AIS. Allele C of rs9403380, allele G of rs6570507, and allele A of rs7774095 can significantly add to the risk of AIS with an odds ratio of 1.17, 1.16, and 1.15, respectively. Patients with AIS were found to have significantly higher GPR126 expression than controls. Moreover, there was significant difference between the expression of the GPR126 in the concave side and convex side of the patients with AIS. Patients with rs9403380 genotype CC have a significantly increased expression of GPR126 than those with TT. Rs9403380 could be a functional variant regulating the expression of GPR126 in the paraspinal muscles of AIS, which may serve as a potential biomarker for the early diagnosis of AIS. N/A.

Pulmonary function and thoracic deformities in adolescent idiopathic scoliosis 27 years or longer after spinal fusion with Harrington instrument.

The aim of this study was to conduct an investigation into spinal fusion with Harrington instrument (HI) in patients with adolescent idiopathic scoliosis (AIS) and to survey pulmonary function and thoracic deformity outcomes many years after surgery. Subjects comprised 194 patients diagnosed with AIS and treated with spinal fusion using HI between 1968 and 1987. Patients who gave their informed consent were subjected to a complete standing spine X-ray, chest CT, and pulmonary function tests. Eighteen patients were eligible for inclusion. Mean age at the time of follow-up was 49.9 years and the mean duration of follow-up was 35.3 years. CT axial image was used at the apex of the main thoracic curve. Apical vertebral rotation was determined from RA sag measured by the method of Aaro etal. Thoracic cage deformities were measured as follows: Rib hump index (RHi) according to the method of Aaro etal. and posterior hemithoracic symmetry ratio (PHSr) according to the method of Campbell etal. Pulmonary function tests revealed mean forced vital capacity (FVC) of 2.28 (range: 1.00-3.04) L and mean %FVC of 83.5% (range: 35.6%-117.8%). Restrictive ventilation disorder with %FVC <80% was seen in 5 patients (27.7%). %FVC had strong negative correlations with RA sag (r=-0.798), RHi (r=-0.820, p<0.001), PHSr (r=-0.705), and proximal thoracic curve (r=-0.721). Main thoracic curve (r=-0.674) and apical vertebral rotation of thoracic curve (r=-0.685) showed moderate negative correlations. Multiple regression analysis revealed RHi was a most significant factor on %FVC. In AIS patients examined 27 years or longer after surgery, restrictive ventilation defects were observed in 27.7%. Factors aggravating %FVC were large rib humps and large vertebral rotations. Three-dimensional correction of the spine and thoracic cage deformities is vital in order to avoid pulmonary function impairment many years after surgery.

Axial Plane Deformity of the Shoulder in Adolescent Idiopathic Scoliosis.

Prospective observational study. To study axial plane deformation of the shoulder in adolescent idiopathic scoliosis (AIS) and try to correlate it with curve type and surgical correction. It is established that AIS is a 3-dimensional deformity. The rib hump is the most common manifestation of axial plane deformations; the least common manifestation seems to be upper trunk and shoulder rotation, which has been hitherto undescribed. Fourteen consecutive, operated cases of AIS were analyzed prospectively. Preoperative and postoperative x-rays of the spine and clinical photographs were studied. Clinical photographs (top view) were taken with patients in the sitting position, to show shoulder level in relation to the axis of the head and pelvis. Chest computed tomography scans were also studied to determine the direction of apical vertebra and trunk torsion. All 14 patients in this series had their right shoulders anteriorly rotated preoperatively (anticlockwise). The direction of rotation seemed unrelated to the curve type and shoulder elevation, although most had rib humps on the right. This shoulder rotation was corrected postoperatively by routine maneuvers done for scoliosis correction. Minor residual rotation was seen in 6 patients who also had minimal persisting rib hump. In 1 case the axial plane rotation worsened, although the shoulder level and trunk symmetry improved significantly. The apical vertebral rotation on computed tomography had little bearing on the direction of shoulder rotation. Axial plane rotation of the shoulder is a hitherto un-described dimension of AIS deformity complex. Much of it corrects spontaneously with correction of the thoracic spinal deformity.

Genetic variant of BNC2 gene is functionally associated with adolescent idiopathic scoliosis in Chinese population.

Adolescent idiopathic scoliosis (AIS) is a structural curvature of the spine that was estimated to affect millions of children worldwide. Recent study shows that the functional variant rs10738445 could add to the risk of AIS through the regulation of BNC2 gene. This study aims to investigate whether the rs10738445 of BNC2 gene is a functional susceptible locus for AIS in the Chinese population and to further clarify the association of the BNC2 expression with the curve severity. SNP rs10738445 was genotyped in 1952 patients and 2492 controls, and further replicated in 693 patients and 254 controls. We found that patients have a significantly higher frequency of CC than the controls (21.9 vs. 17.7%, p = 0.004 for stage 1; 12.6 vs. 7.9%, p = 0.03 for stage 2). Allele C can significantly add to the risk of AIS with an OR of 1.14-1.24. AIS patients were found to have significantly higher BNC2 expression than the controls. The BNC2 expression was significantly correlated with the curve severity (r = 0.316, p = 0.02). In conclusion, our study suggests a functional role of BNC2 in the development and progression of the spinal deformity in AIS.

Posterior Selective Fusion with Pedicle Instrumented Correction in Thoracic and Thoracolumbar Idiopathic Scoliosis

Introduction To evaluate clinical and radiological outcome of selective fusion for adolescent idiopathic scoliosis (AIS) in thoracic and thoraco-lumbar curves i.e., Lenke 1C and 5C curves. Material and Methods 32 consecutive patients (22 females, 10 males) with 20 Lenke 1 C and 12 Lenke 5C were operated through posterior approach for AIS. Risser stage at the time of operation was 0–3 in 24patients and more than 3 in 4patients. Mean age was 13.5 years. Not every vertebra was instrumented with pedicle screws. Apical vertebral derotation and translation on the concave side were performed for correction. All patients underwent a selective fusion (1C only thoracic curve fused; 5C only thoracolumbar/lumbar curve fused). The data were prospectively collected preoperatively and at 6 weeks, 1year and 2 years post-operatively. Cobb angle, sagittal and coronal balance, and lowest fused vertebral tilt were documented at all time-points. Uninstrumented compensatory curves were measured at all time points. Results Lowest instrumented vertebra (LIV) was distal end vertebra in 15 patients and was one below distal end vertebra in 3 patients in Lenke1C curves. The main thoracic curve correction in Lenke1C was 66%, from 60° ± 12° preoperative to 20° ± 7° at 6 weeks. The Cobb angle was 20° ± 10° at 1 years and 24° ± 10° at 2 years. The apical vertebral rotation improved by 38%, the non-instrumented lumbar curves improved 50%. The last instrumented vertebral tilt decreased from 22° ± 8° preoperatively to 5° ± 5° postoperatively. The average thoracolumbar/lumbar (TL/L) preoperative Cobb angle in Lenke5C curves was 46° ± 8° which was corrected to 14° ± 7° (70% correction) at a 2-year follow-up. 25% of the uninstrumented thoracic curve had spontaneous correction. The coronal balance improved significantly ( p &lt; 0.05) and remained stable from the first postoperative visit to the 2-year follow-up visit. The SRS-22 total scores improved significantly from before surgery to 2years after surgery ( p &lt; 0.0001). No pseudarthrosis or reoperation was observed. One 12 girl with Lenke1C (65°) had intra-operative loss of neural monitoring signals who was paralysed postoperatively for a period of 2 weeks. She recovered completely by 2 months. Conclusion Posterior correction of thoracic and thoracolumbar AIS with pedicle screw instrumentation is safe and produces a long-term stable correction and high patient satisfaction. In Lenke 1C and 5C AIS deformity patterns fused selectively, the uninstrumented compensatory curves do not seem to progress. Selective fusions, when successfully performed, will optimize mobile segments of the spine in AIS patients.

Posterior Selective Fusion with Pedicle Instrumented Correction in Thoracolumbar Adolescent Idiopathic Scoliosis (AIS)

Introduction To evaluate clinical and radiological outcome of selective fusion for adolescent idiopathic scoliosis (AIS) in thoraco-lumbar curves i.e., Lenke 5C curves. Material and Methods Twelve(12) patients with Lenke 5C curves were operated through posterior approach for AIS. Risser stage at the time of operation was 0–3 in 6patients and more than 3 in 4patients. Mean age was 13.5 years. Not every vertebra was instrumented with pedicle screws. Apical vertebral derotation and translation on the concave side were performed for correction. All patients underwent a selective fusion (5C only thoracolumbar/lumbar curve fused). The data were prospectively collected preoperatively and at 6 weeks, 1year and 2years post-operatively. Cobb angle, sagittal and coronal balance, and lowest fused vertebral tilt were documented at all time-points. Uninstrumented compensatory curves were measured at all time points. Results The average thoracolumbar/lumbar (TL/L) preoperative Cobb angle in Lenke5C curves was 46° ± 8° which was corrected to 14° ± 7° (70% correction) at a 2-year follow-up. 25% of the uninstrumented thoracic curve had spontaneous correction. The coronal balance improved significantly ( p &lt; 0.05) and remained stable from the first postoperative visit to the 2-year follow-up visit. The SRS-22 total scores improved significantly from before surgery to 2years after surgery ( p &lt; 0.0001). No pseudarthrosis or reoperation was observed. Conclusion Posterior correction of thoracolumbar AIS with pedicle screw instrumentation is safe and produces a long-term stable correction and high patient satisfaction. In Lenke 5C AIS deformity patterns fused selectively, the uninstrumented compensatory curves do not seem to progress. Selective fusions, when successfully performed, will optimize mobile segments of the spine in AIS patients.

Three-dimensional morphology study of surgical adolescent idiopathic scoliosis patient from encoded geometric models.

The classification of three-dimensional (3D) spinal deformities remains an open question in adolescent idiopathic scoliosis. Recent studies have investigated pattern classification based on explicit clinical parameters. An emerging trend however seeks to simplify complex spine geometries and capture the predominant modes of variability of the deformation. The objective of this study is to perform a 3D characterization and morphology analysis of the thoracic and thoraco/lumbar scoliotic spines (cross-sectional study). The presence of subgroups within all Lenke types will be investigated by analyzing a simplified representation of the geometric 3D reconstruction of a patient's spine, and to establish the basis for a new classification approach based on a machine learning algorithm. Three-dimensional reconstructions of coronal and sagittal standing radiographs of 663 patients, for a total of 915 visits, covering all types of deformities in adolescent idiopathic scoliosis (single, double and triple curves) and reviewed by the 3D Classification Committee of the Scoliosis Research Society, were analyzed using a machine learning algorithm based on stacked auto-encoders. The codes produced for each 3D reconstruction would be then grouped together using an unsupervised clustering method. For each identified cluster, Cobb angle and orientation of the plane of maximum curvature in the thoracic and lumbar curves, axial rotation of the apical vertebrae, kyphosis (T4-T12), lordosis (L1-S1) and pelvic incidence were obtained. No assumptions were made regarding grouping tendencies in the data nor were the number of clusters predefined. Eleven groups were revealed from the 915 visits, wherein the location of the main curve, kyphosis and lordosis were the three major discriminating factors with slight overlap between groups. Two main groups emerge among the eleven different clusters of patients: a first with small thoracic deformities and large lumbar deformities, while the other with large thoracic deformities and small lumbar curvature. The main factor that allowed identifying eleven distinct subgroups within the surgical patients (major curves) from Lenke type-1 to type-6 curves, was the location of the apical vertebra as identified by the planes of maximum curvature obtained in both thoracic and thoraco/lumbar segments. Both hypokyphotic and hyperkypothic clusters were primarily composed of Lenke 1-4 curve type patients, while a hyperlordotic cluster was composed of Lenke 5 and 6 curve type patients. The stacked auto-encoder analysis technique helped to simplify the complex nature of 3D spine models, while preserving the intrinsic properties that are typically measured with explicit parameters derived from the 3D reconstruction.

Adolescent Idiopathic Scoliosis: An in Depth Analysis and Historical Review

Adolescent idiopathic Scoliosis (AIS) is a common disorder of children about which there is a vast amount of research available for review. This manuscript aims to discuss significant classic and modern literature regarding this spinal deformity. An organized review of topics including the definition, epidemiology, etiology, physiology, diagnosis, and management of adolescent idiopathic scoliosis has been included herein. In this review, it is first explained that AIS now falls under the definition of late-onset idiopathic scoliosis. Epidemiologic discussion then reveals the relatively high prevalence of this disorder in children and lists the variations seen in prevalence by gender. Etiologic review explores the multifactorial nature of AIS and describes various conditions implicated in AIS pathogenesis including abnormalities in connective tissue structure, neuro-osseous development, platelet chemistry and hormone levels. The discussion of physiology explains the three dimensional structure of the AIS deformity and reviews long term complications such as back pain and compromised self-image. The section covering diagnostic methods highlights the physical exam for AIS and details important radiographic measurements including the Cobb angle, clavicle angle, and sagittal balance. Finally, the review of management emphasizes the importance of individualized therapy for AIS and discusses techniques involved in the non-operative and operative treatment of this spinal deformity.

The biomechanical effects of spinal fusion on the sacral loading in adolescent idiopathic scoliosis

BackgroundPosterior spinal surgical correction is performed to correct spinal deformities in adolescent idiopathic scoliosis. Althoughthe relative spino-pelvic alignment changes after spinal surgery, pelvis remains unfused in idiopathic scoliosis surgery. The impact of the spinal fusion on the transferred load to the pelvis via sacrum is not documented in the scoliotic subgroups. MethodBi-planar radiographs of 9 scoliotic subjects before and in average 16months after spinal instrumentation surgery, and 12 controls were selected retrospectively. Patient-specific 3D reconstruction and finite element models of the spine, ribcage, and pelvis were developed. Spinal parameters (Cobb angles, kyphosis, lordosis), sacro-pelvic parameters (pelvic incidence, pelvic tilt, sacral slope), frontal and sagittal balances, the position of the trunk center of mass, and the centroid of the stress distribution on the sacrum superior endplate were measured and computed before operation and in the last follow-up. FindingsThe position of the stress distribution centroid on the sacrum superior endplate with respect to the central hip vertical axis was significantly different between pre-operative and post-operative patients p<0.05. The distance between the anterior–posterior position of the trunk center of mass and thecenter of pressure on the superior sacral endplate significantly decreased after the spinal surgery p<0.05. InterpretationThe impact of the scoliosis spinal fusion on the transferred load between the spine and pelvis was evaluated. The biomechanical loading of the sacrum endplate was related to the post-operative postural balance and compensatory changes in the spino-pelvic alignment after scoliosis surgery.

Analysis of the relationship between coronal and sagittal deformities in adolescent idiopathic scoliosis.

To characterize the sagittal alignment of each Lenke type and investigate the relationship between coronal and sagittal deformities in adolescent idiopathic scoliotic (AIS) patients. A cohort of 184 subjects with AIS was retrospectively recruited. Radiographic data were measured and collected, including the Lenke types, Cobb angles of structural curves, and sagittal spino-pelvic parameters. Subjects were grouped according to their genders, Lenke curve types, lumbar modifiers and the amount of coronal structural curves. The sagittal alignment was then compared between the different groups, and correlation analysis was also taken between coronal and sagittal parameters. Besides, each subject's Roussouly type was decided and its distribution was compared among different Lenke types. The cohort included 59 males and 125 females, averagely aged at 15.5 ± 3.3 years old. Most sagittal parameters except thoracic kyphosis (TK) and pelvic tilt (PT) were similar among different Lenke types, while all the sagittal parameters were similar between males and females. The groups with different lumbar modifiers had similar sagittal parameters except TK, which was also true for the groups with different amounts of coronal curves. 42.4 % of the cohort belonged to Roussouly type 3, and the distribution of Roussouly types was comparable among all Lenke types. All sagittal parameters except C7 translation ratio were significantly different among Roussouly types (P < 0.05). Correlation analysis showed that main thoracic (MT) was negatively correlated with lumbar lordosis (LL, r = -0.324), sacral slope (r = -0.321) and spino-sacral angle (r = -0.363). Partial correlation analysis found that thoracolumbar/lumbar was negatively correlated with TK (r = -0.464) and LL (r = -0.422) when MT was controlled. The influence of coronal deformity on sagittal parameters was limited and mainly reflected in the deviation of TK. Most coronal and sagittal parameters were not significantly correlated, and the coronal deformity types did not change the global sagittal postural patterns.

The Biomechanics of Spinal Deformity in Adolescent Idiopathic Scoliosis

Given the variety of anatomic and physical variations that exist, the biomechanics of Adolescent Idiopathic Scoliosis (AIS) comprise a complex topic. Representing the fundamental mechanism behind the three-dimensional deformities observed in this condition, AIS develops as a result of these complex interactions between pathoanatomy and the developmental biomechanics of the spine. The progressive nature of the deformity relates to the interplay between bony anatomical alterations and the surrounding soft tissue response. Various classification systems have evolved to better understand AIS and provide guidance for its management, and myriad techniques have been developed to address the correction of spinal deformity in these patients. For appropriately selected patients, the treating surgeon must exploit all biomechanical advantages available t counteract these deforming forces, and it is important that the biomechanics contributing to the progression of this condition be understood and corrected. All aspects of the case, including preoperative positioning and implant utilization, play a role in the amount of correction that can be obtained and maintained. These implants affect— and are affected by the forces present on the deformed spine, and manipulation of the surrounding anatomy may aid in obtaining the best surgical outcome.

Three-Dimensional Spinopelvic Relative Alignment in Adolescent Idiopathic Scoliosis

Three-dimensional (3D) analysis of the spinopelvic alignment in adolescent idiopathic scoliosis (AIS). To study the 3D pelvic alignment with respect to the spinal deformities in AIS subgroups. Spinopelvic alignment is subject to change in scoliosis. Many sacropelvic parameters were developed to characterize spinopelvic alignment in the sagittal plane. However, not much is known about the 3D pelvic alignment with respect to the thoracic and lumbar spinal deformities in AIS. Eighty AIS subjects with right main thoracic (MT), 80 AIS with left thoracolumbar/lumbar (TL/L) curves, and 35 asymptomatic controls were included. Thoracic and lumbar Cobb angles, kyphosis, lordosis, pelvic incidence, pelvic tilt, and sacral slope were measured. Pelvic tilt and axial rotation in the coronal and transverse planes, respectively, were computed using the ipsilateral anterior superior iliac spine and posterior superior iliac spine positions. Leg length discrepancy was determined by the vertical difference in the position of the center of the femoral heads in the coronal plane. In 59% of the MT subjects and 79% of the TL/L subjects in the erect position, the pelvis was tilted toward the convex side of the major curve in the coronal plane. The direction of the pelvic axial rotation in the transverse plane was in the same direction as the MT apical vertebra rotation in 84% of the MT subjects and 55% of the TL/L group. The pelvic incidence correlated to the lumbar lordosis in AIS (r = 0.41, P < 0.001). Pelvic coronal tilt correlated significantly to the leg length discrepancy in MT (r = 0.67) and TL/L (r = 0.61) subjects (P < 0.001). Novel pelvic parameters were introduced to characterize the spinopelvic relative alignment in scoliotic subgroups. The proposed method related the orientation of the pelvis in the coronal and transverse planes to both thoracic and lumbar spinal deformities.

The formetric TRACER index: a valid measure of aesthetic deformity in adolescent idiopathic scoliosis

Background The gold standard of scoliosis evaluation-Cobb angle measurement-is a valuable tool for assessing spinal deformity and making therapeutic decisions [1,2] but is not fully able to describe the trunk deformity (aesthetics), which is a main concern of patients. Posture, deformity of other bones and soft tissues could be other determinants of the aesthetic impairment due to scoliosis. We do not currently have a commonly accepted measurement of aesthetic impairment due to scoliosis. Purpose The goal of this study was to find a parametric measure to describe aesthetic impairment due to scoliosis. Design: Cross-sectional study. Population: 119 adolescent idiopathic scoliosis (AIS) patients (10.0% males, age 13.9±2.3, 25.4±10.9° Cobb). The sample was randomly divided into two subgroups. Methods Repeated formetric evaluations and simultaneous pictures of the back were performed. An online questionnaire with the photos was completed by 41 laypeople with no scoliosis experience (53.6% males, age 30.3±13.3), who judged the photos on a 0-3 Likert scale (0 normal, 3 highly asymmetric). Statistics: On the first subgroup, we performed a stepwise forward regression technique considering as dependent variable the median of the results of the questionnaire, and as independent variable formetric, clinical and radiological parameters. On the second group, we checked the correlation between the index found (TRACER) and the median of the results of the questionnaire (Spearman’s Rho). Finally, we checked the test-retest repeatability (Spearman’s Rho), concurrent (Spearman’s Rho) and diagnostic (T-test) validity of the index we found. Results The following formula was found: TRACER= [0.726+ (CobbMax*0,018)+(SurfaceRotation*0.037)]/3*100. This TRACER index (0-100) was well-correlated (Rho=0.414, p<0.01) with the median of the questionnaire results in the second group; it was also highly repeatable (Rho=0.922), strongly correlated to Cobb degrees (Rho=0.838), mildly correlated to TRACE index [3] (Rho=0.376) and distinguished pathological and healthy subjects (p<0.01). Conclusions and discussion The TRACER index could be used to measure aesthetic deformity in AIS patients; however, further studies are needed to investigate its role in the conservative and surgical treatment of scoliosis.

Whither the etiopathogenesis (and scoliogeny) of adolescent idiopathic scoliosis? Incorporating presentations on scoliogeny at the 2012 IRSSD and SRS meetings

This paper aims to integrate into current understanding of AIS causation, etiopathogenetic information presented at two Meetings during 2012 namely, the International Research Society of Spinal Deformities (IRSSD) and the Scoliosis Research Society (SRS). The ultimate hope is to prevent the occurrence or progression of the spinal deformity of AIS with non-invasive treatment, possibly medical. This might be attained by personalised polymechanistic preventive therapy targeting the appropriate etiology and/or etiopathogenetic pathways, to avoid fusion and maintain spinal mobility. Although considerable progress had been made in the past two decades in understanding the etiopathogenesis of adolescent idiopathic scoliosis (AIS), it still lacks an agreed theory of etiopathogenesis. One problem may be that AIS results not from one cause, but several that interact with various genetic predisposing factors. There is a view there are two other pathogenic processes for idiopathic scoliosis namely, initiating (or inducing), and those that cause curve progression. Twin studies and observations of family aggregation have revealed significant genetic contributions to idiopathic scoliosis, that place AIS among other common disease or complex traits with a high heritability interpreted by the genetic variant hypothesis of disease. We summarize etiopathogenetic knowledge of AIS as theories of pathogenesis including recent multiple concepts, and blood tests for AIS based on predictive biomarkers and genetic variants that signify disease risk. There is increasing evidence for the possibility of an underlying neurological disorder for AIS, research which holds promise. Like brain research, most AIS workers focus on their own corner and there is a need for greater integration of research effort. Epigenetics, a relatively recent field, evaluates factors concerned with gene expression in relation to environment, disease, normal development and aging, with a complex regulation across the genome during the first decade of life. Research on the role of environmental factors, epigenetics and chronic non-communicable diseases (NCDs) including adiposity, after a slow start, has exploded in the last decade. Not so for AIS research and the environment where, except for monozygotic twin studies, there are only sporadic reports to suggest that environmental factors are at work in etiology. Here, we examine epigenetic concepts as they may relate to human development, normal life history phases and AIS pathogenesis. Although AIS is not regarded as an NCD, like them, it is associated with whole organism metabolic phenomena, including lower body mass index, lower circulating leptin levels and other systemic disorders. Some epigenetic research applied to Silver-Russell syndrome and adiposity is examined, from which suggestions are made for consideration of AIS epigenetic research, cross-sectional and longitudinal. The word scoliogeny is suggested to include etiology, pathogenesis and pathomechanism.

Comparison of trunk and spine deformity in adolescent idiopathic scoliosis.

BackgroundCobb measurement of standing radiographs is the standard for clinical assessment of coronal spinal deformity. Angle of trunk inclination (ATI) is an accepted clinical measurement of trunk asymmetry, and has variable reported correlations with Cobb angles. Transverse plane spine deformity is most accurately measured using axial computed tomography. Aaro and Dahlbourn’s technique for quantifying apical vertebral rotation with respect to the sagittal plane (RAsag) is commonly reported in the literature. To our knowledge no study has correlated ATI with RAsag. The purpose of this study was to determine the relationship between commonly used measures of trunk and spine deformity.MethodsSixteen females that underwent preoperative apical vertebra(e) CT scans were retrospectively studied. Thoracic and thoracolumbar RAsag measurements were date-matched to clinically obtained ATI and Cobb measurements. Two-tailed Pearson correlations were calculated; α = 0.01.ResultsMedian patient age was 14.6 years (11–19); BMI 19.4 (16.0-25.5). Curve patterns: Lenke 1 (5); 2 (5); 3 (1); 4 (1); 5 (2): 6 (2). Twenty-six curves (15T; 11TL) with complete, date-matched data points were analyzed. In thoracic curves, ATI correlated with Cobb (r = 0.711, P < 0.004) and RAsag (r = 0.730, P <0.003). ATI was inversely correlated with Cobb flexibility (r = −0.647, P < 0.01). In thoracolumbar curves, ATI correlated with Cobb (r = 0.789, P < 0.005), and RAsag (r = 0.771, P < 0.006) but not Cobb flexibility (r = −0.452, P = 0.190).ConclusionsTrunk and spine thoracic and thoracolumbar transverse plane deformity are correlated, as are trunk transverse plane and spine coronal plane deformity. Increasing trunk deformity limits thoracic, but not thoracolumbar spine flexibility.