scholarly journals Analysis of Proximal Femoral Parameters in Adolescent Idiopathic Scoliosis

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Máté Burkus ◽  
Ádám T. Schlégl ◽  
Kristóf József ◽  
Ian O’Sullivan ◽  
István Márkus ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Mechanical Axis ◽  
Three Dimensional ◽  
Femoral Shaft ◽  
Neck Shaft Angle ◽  
Shaft Angle ◽  
Spinal Abnormality ◽  
Lower Neck ◽  
Femoral Mechanical Axis

Background. Assessment of the proximal femoral parameters in adolescent idiopathic scoliosis using three-dimensional radiological image reconstructions may allow better characterization than conventional techniques. Methods. EOS 3D reconstructions of spines and femurs of 320 scoliotic patients (10-18 years old) and 350 control children lacking spinal abnormality were performed and 6 proximal femoral parameters measured. Results. Individuals with adolescent idiopathic scoliosis showed a small but statistically significant decrease in neck shaft angle (average difference=2.58°) and a higher (0.22°) femoral mechanical axis–femoral shaft angle. When the two sides were compared based on curve direction, greater changes in the neck shaft angle and femoral mechanical axis–femoral shaft angle were found on the side of the convexity. Conclusions. Patients with adolescent idiopathic scoliosis were found to have a small but significantly lower neck shaft angle and higher femoral mechanical axis–femoral shaft angle, which related to the curve direction. This is postulated to be due to mechanical compensation for altered balance and centre of gravity associated with a scoliosis deformity, although the observed difference likely has negligible clinical effect.

scholarly journals Specific sagittal alignment patterns are already present in mild adolescent idiopathic scoliosis

2021 ◽  
Author(s):  
Tom P. C. Schlösser ◽  
René M. Castelein ◽  
Pierre Grobost ◽  
Suken A. Shah ◽  
Kariman Abelin-Genevois
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Inflection Point ◽  
Thoracic Kyphosis ◽  
Sagittal Alignment ◽  
Three Dimensional ◽  
Sagittal Profile ◽  
Thoracolumbar Kyphosis ◽  
C7 Slope ◽  
Sagittal Malalignment

Abstract Purpose The complex three-dimensional spinal deformity in AIS consists of rotated, lordotic apical areas and neutral junctional zones that modify the spine’s sagittal profile. Recently, three specific patterns of thoracic sagittal ‘malalignment’ were described for severe AIS. The aim of this study is to define whether specific patterns of pathological sagittal alignment are already present in mild AIS. Methods Lateral spinal radiographs of 192 mild (10°–20°) and 253 severe (> 45°) AIS patients and 156 controls were derived from an international consortium. Kyphosis characteristics (T4–T12 thoracic kyphosis, T10–L2 angle, C7 slope, location of the apex of kyphosis and of the inflection point) and sagittal curve types according to Abelin-Genevois were systematically compared between the three cohorts. Results Even in mild thoracic AIS, already 49% of the curves presented sagittal malalignment, mostly thoracic hypokyphosis, whereas only 13% of the (thoraco) lumbar curves and 6% of the nonscoliosis adolescents were hypokyphotic. In severe AIS, 63% had a sagittal malalignment. Hypokyphosis + thoracolumbar kyphosis occurred more frequently in high-PI and primary lumbar curves, whereas cervicothoracic kyphosis occurred more in double thoracic curves. Conclusions Pathological sagittal patterns are often already present in curves 10°–20°, whereas those are rare in non-scoliotic adolescents. This suggests that sagittal ‘malalignment’ patterns are an integral part of the early pathogenesis of AIS.

scholarly journals THE ETIOLOGIC RELEVANCE OF 3-D PATHOANATOMY OF ADOLESCENT IDIOPATHIC SCOLIOSIS

2017 ◽  
Vol 16 (4) ◽  
pp. 302-307
Author(s):  
Tom Schlösser ◽  
Rob Brink ◽  
René Castelein
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Three Dimensional ◽  
Imaging Studies ◽  
Cross Sectional ◽  
Ongoing Research ◽  
Biomechanical Loading ◽  
Cross Sectional Imaging ◽  
Sectional Imaging ◽  
The One

ABSTRACT Despite many years of dedicated research into the etiopathogenesis of adolescent idiopathic scoliosis, there is still no single distinct cause for this puzzling condition. In this overview, we attempt to link knowledge on the complex three-dimensional pathoanatomy of AIS, based on our ongoing research in this field, with etiopathogenic questions. Evidence from multiple recent cross-sectional imaging studies is provided that supports the hypothesis that AIS has an intrinsic biomechanical basis: an imbalance between the biomechanical loading of the upright human spine due to its unique sagittal configuration on the one hand, and the body’s compensating mechanisms on the other. The question that remains in the etiology of AIS, and the focus of our ongoing research, is to determine what causes or induces this imbalance.

scholarly journals Standard Radiographic Assessment of Femoral Cam Morphology is Influenced by Neck-Shaft Angle and Femoral Version

2020 ◽  
Vol 8 (7_suppl6) ◽  
pp. 2325967120S0039
Author(s):  
Layla Haidar ◽  
Ryan Warth ◽  
Erinn Pemberton Annie Waite ◽  
Alfred Mansour
Keyword(s):  
Femoral Head ◽  
Alpha Angle ◽  
Three Dimensional ◽  
Neck Shaft Angle ◽  
Incremental Change ◽  
Observer Reliability ◽  
Angle Measurements ◽  
Femoral Version ◽  
Shaft Angle ◽  
Head Neck

Objectives: Cam-type femoroacetabular impingement (FAI) is a three-dimensional (3D) deformity that is still difficult to assess using traditional two-dimensional (2D) radiographic views. While measurements of alpha angle and head-neck offset are used to estimate the likelihood of actual impingement, these 2D measurements do not account for z-axis variations in femoral version (FV) and neck-shaft angle (NSA). The purpose of this qualitative proof-of-concept study was to evaluate the potential variation in alpha angle and neck-shaft offset measurements with incremental changes in NSA and FV by simulating traditional radiographic views with software-generated Digitally-Reconstructed Radiographs (DRRs). We hypothesize that incremental changes in hip morphology will produce qualitative changes in alpha angle and neck-shaft offset. Methods: 3D-CT reconstruction images were obtained from one subject with symptomatic cam-type FAI. The 3D reconstruction was cleaned to include only the femoral head, neck and subtrochanteric region along with the ipsilateral hemipelvis. Using 3D medical image processing software (Mimics; Materialise, Inc.; Belgium), the pre-processed 3D model was manipulated in a standardized manner to simulate 5-degree incremental variations in FV and NSA (-15 degrees to +15 degrees for FV; -15 degrees to +10 degrees for NSA). Negative FV reflected external rotation of the femoral head-neck unit, whereas negative NSA reflected abduction of the femoral head-neck unit. Each modified 3D model was then used to generate DRRs corresponding to traditional 2D radiographic views used for assessment of cam-FAI (Anteroposterior [AP], False Profile [FP]), Cross Table Lateral [CTL], Frog Leg Lateral [FLL], 45- and 90-degree Dunn [45D and 90D, respectively]. Alpha angle and head-neck offset were measured on each radiographic view corresponding to each incremental change in FV and NSA. All measurements utilized the perfect circle technique and were made by two independent observers for assessment of inter-observer reliability. Two-way random effects ANOVA was used for statistical assessment of inter-observer reliability and reported as intra-class correlation coefficients (κ). Comparisons between groups were performed using two-tailed paired t-tests assuming unequal variance. P-values less than 0.05 were considered statistically significant. Results: Inter-observer reliability (κ) for head-neck offset and alpha angles were 0.46 (fair) and 0.88 (excellent), respectively. Variations in head-neck offset and alpha angle with incremental variations in FV and NSA are summarized in Figure 1. There were statistically significant changes in mean alpha angles when the NSA was adjusted from Neutral to -5 degrees (p=0.01) and from -5 degrees to -10 degrees (p<0.001). There were no statistically significant differences in alpha angles or head-neck offsets between each incremental change in FV (p<0.05). Alpha angle measurements were significantly more variable than head-neck offset measurements for all variations in FV (p<0.001) and NSA (p=0.02) (Figure 2). Conclusion: Two-dimensional evaluation of three-dimensional Cam morphology (alpha angle and head-neck offset) was found to be significantly affected by alterations in femoral version and head-neck offset. Head-neck offset measurements were significantly less variable than alpha angle measurements across all FVs and NSAs within each radiographic view. Future work should be done to develop standardized procedures for routine 3D radiographic assessment of cam-type FAI. [Figure: see text][Figure: see text]

Adolescent Idiopathic Scoliosis – Future Molecular-Based Diagnostic and Prognostic Testing

2019 ◽  
Vol 21 (4) ◽  
pp. 253-260
Author(s):  
Radoslav Zamborský ◽  
Boris Liščák ◽  
Martin Trepáč ◽  
Andrey Švec ◽  
Ľuboš Danisovič
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Association Studies ◽  
Three Dimensional ◽  
Reliability And Validity ◽  
Genome Project ◽  
Genome Wide Association Studies ◽  
Appropriate Treatment ◽  
Surgical Treatments ◽  
The Human Genome Project

Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine mainly affecting the younger population. Earlier detection of the disorder leads to appropriate treatment and better outcomes, thus avoiding highly invasive surgical treatments. The currently available tests for the disease identification have lost their reliability and validity with time. In the past few decades, efforts have been directed towards developing a highly reliable prognostic test for AIS. Towards this end, several strategies have been employed including biochemical, biomechanical and gene-based tests. Among the three, the gene-based technology has received much attention in recent past. Notably, this is due to the fact that the human genome project, followed by genome-wide association studies (GWAS), facilitated the identification of candidate genes for disorders like AIS. Several promising biomarker genes have been identified. However, their global validations were disappointing as these genes were shown to be limited to a particular group of people/ethnicities. Such observations limit the development of a reliable global molecular/biochemical test for AIS. The currently used AIS ScoliScoreTM also has several limitations. With continued disappointments in the identification of biomarkers for AIS and lack of appropriate tests, researchers have diverted their efforts towards several alternative avenues. A ray of hope is emerging from recent observations on the association of non-coding microRNAs and epigenetic factors that might arise as future reliable markers for AIS, thus paving the way for appropriate clinical management of this disorder.

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