The heritability of coronal and sagittal phenotype in idiopathic scoliosis: a report of 12 monozygotic twin pairs

Abstract Purpose One of the pathways through which genetics may act in the causation of idiopathic scoliosis is inheritance of a specific sagittal profile that predisposes for its development. In this study, coronal and sagittal parameters were compared in an international collection of monozygotic twins with idiopathic scoliosis. Methods Twelve monozygotic twin pairs who underwent biplanar radiography for idiopathic scoliosis were systematically identified in existing scoliosis databases in The Netherlands, Sweden, and Denmark. On the first available radiographs, the coronal and sagittal curve parameters (Roussouly and Abelin types, thoracic kyphosis, lumbar lordosis and length of the posteriorly inclined segment) were determined. Results In all 12 monozygotic twin pairs, both twins were affected by AIS. Four (33%) twin pairs had similar coronal and sagittal spinal phenotype, whereas two (17%) had different coronal phenotype and similar sagittal profiles, and six (50%) pairs had different coronal as well as sagittal phenotype. Conclusions Analysis of biplanar curve characteristics in monozygotic twins showed that all twin pairs were affected by idiopathic scoliosis. However, only 33% of the pairs had similar coronal and sagittal spinal phenotypes. Based on this limited dataset, the hypothesis can be formulated that besides genetic pre-disposition, the individual (inherited) sagittal profile plays a role in the development of different coronal curve type.

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Sagittal profile modifications in hybrid versus all screw technique in adolescent idiopathic scoliosis

Scientific Reports ◽

10.1038/s41598-020-79523-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Laura Scaramuzzo ◽

Antonino Zagra ◽

Giuseppe Barone ◽

Stefano Muzzi ◽

Leone Minoia ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Cobb Angle ◽

Thoracic Kyphosis ◽

Sagittal Alignment ◽

Vertical Axis ◽

Sagittal Profile ◽

Sacral Slope ◽

Sagittal Vertical Axis ◽

Lenke Classification

AbstractAim of the study was to evaluate sagittal parameters modifications, with particular interest in thoracic kyphosis, in patients affected by adolescent idiopathic scoliosis (AIS) comparing hybrid and all-screws technique. From June 2010 to September 2018, 145 patients were enrolled. Evaluation included: Lenke classification, Risser scale, coronal Cobb angle, thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS). Patients were divided in two groups (1 all-screws and 2 hybrid); a further division, in both groups, was done considering preoperative TK values. Descriptive and inferential statistical analysis was conducted. 99 patients were in group 1, 46 in group 2 (mean follow-up 3.7 years). Patients with a normo-kyphotic profile developed a little variation in TK (Δ pre–post = 2.4° versus − 2.0° respectively). Hyper-kyphotic subgroups had a tendency of restoring a good sagittal alignment. Hypo-kyphotic subgroups, patients treated with all-screw implants developed a higher increase in TK mean Cobb angle (Δ pre–post = 10°) than the hybrid subgroup (Δ pre–post = 5.4°) (p = 0.01). All-screws group showed better results in restoring sagittal alignment in all subgroups compared to hybrid groups, especially in hypo-TK subgroup, with the important advantage to give better correction on coronal plane.

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

European Spine Journal ◽

10.1007/s00586-021-06772-w ◽

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.

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Normal Age-Adjusted Sagittal Spinal Alignment Is Achieved with Surgical Correction in Adolescent Idiopathic Scoliosis

Asian Spine Journal ◽

10.4184/asj.2017.11.5.770 ◽

2017 ◽

Vol 11 (5) ◽

pp. 770-779 ◽

Cited By ~ 1

Author(s):

Subaraman Ramchandran ◽

Norah Foster ◽

Akhila Sure ◽

Thomas J. Errico ◽

Aaron J. Buckland

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Lumbar Lordosis ◽

Thoracic Kyphosis ◽

Pelvic Incidence ◽

Sagittal Alignment ◽

Vertical Axis ◽

Surgical Correction ◽

Sagittal Vertical Axis

<sec><title>Study Design</title>Retrospective analysis.</sec><sec><title>Purpose</title>Our hypothesis is that the surgical correction of adolescent idiopathic scoliosis (AIS) maintains normal sagittal alignment as compared to age-matched normative adolescent population.</sec><sec><title>Overview of Literature</title>Sagittal spino-pelvic alignment in AIS has been reported, however, whether corrective spinal fusion surgery re-establishes normal alignment remains unverified.</sec><sec><title>Methods</title>Sagittal profiles and spino-pelvic parameters of thirty-eight postsurgical correction AIS patients ≤21 years old without prior fusion from a single institution database were compared to previously published normative age-matched data. Coronal and sagittal measurements including structural coronal Cobb angle, pelvic incidence, pelvic tilt, thoracic kyphosis, lumbar lordosis, sagittal vertical axis, C2–C7 cervical lordosis, C2–C7 sagittal vertical axis, and T1 pelvic angles were measured on standing full-body stereoradiographs using validated software to compare preoperative and 6 months postoperative changes with previously published adolescent norms. A sub-group analysis of patients with type 1 Lenke curves was performed comparing preoperative to postoperative alignment and also comparing this with previously published normative values.</sec><sec><title>Results</title>The mean coronal curve of the 38 AIS patients (mean age, 16±2.2 years; 76.3% female) was corrected from 53.6° to 9.6° (80.9%, <italic>p</italic><0.01). None of the thoracic and spino-pelvic sagittal parameters changed significantly after surgery in previously hypo- and normo-kyphotic patients. In hyper-kyphotic patients, thoracic kyphosis decreased (<italic>p</italic>=0.003) with a reciprocal decrease in lumbar lordosis (<italic>p</italic>=0.01), thus lowering pelvic incidence-lumbar lordosis mismatch mismatch (<italic>p</italic>=0.009). Structural thoracic scoliosis patients had slightly more thoracic kyphosis than age-matched patients at baseline and surgical correction of the coronal plane of their scoliosis preserved normal sagittal alignment postoperatively. A sub-analysis of Lenke curve type 1 patients (n=24) demonstrated no statistically significant changes in the sagittal alignment postoperatively despite adequate coronal correction.</sec><sec><title>Conclusions</title>Surgical correction of the coronal plane in AIS patients preserves sagittal and spino-pelvic alignment as compared to age-matched asymptomatic adolescents.</sec>

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How Sublaminar Bands Affect Postoperative Sagittal Alignment in AIS Patients with Preoperative Hypokyphosis? Results of a Series of 34 Patients with 2-Year Follow-Up

BioMed Research International ◽

10.1155/2016/1954712 ◽

2016 ◽

Vol 2016 ◽

pp. 1-5 ◽

Cited By ~ 4

Author(s):

Sébastien Pesenti ◽

Antoine Chalopin ◽

Emilie Peltier ◽

Elie Choufani ◽

Matthieu Ollivier ◽

...

Keyword(s):

Idiopathic Scoliosis ◽

Cobb Angle ◽

Lumbar Lordosis ◽

Thoracic Kyphosis ◽

Radiographic Evaluation ◽

Cervical Lordosis ◽

Pelvic Parameters ◽

Sublaminar Bands ◽

Thoracic Idiopathic Scoliosis

Hypokyphosis is currently observed in thoracic idiopathic scoliosis. The use of sublaminar bands allows a good restoration of sagittal balance of the spine. The aim of the study was to provide a middle-term radiographic analysis of patients with adolescent idiopathic scoliosis with preoperative hypokyphosis treated by posterior arthrodesis with sublaminar bands. This retrospective study included 34 patients with Lenke 1 scoliosis associated with hypokyphosis (TK < 20°). A radiographic evaluation was performed with a 2-year follow-up. Cobb angle, cervical lordosis, thoracic kyphosis, lumbar lordosis, and pelvic parameters were measured preoperatively, postoperatively, and at 6-month and 2-year follow-up. The mean preoperative thoracic kyphosis was 10.5° versus 24.1° postoperatively (p<0.001), representing a mean gain of 13°. Cobb angle ranged from 59.3° to 17.9° postoperatively (mean correction 69%,p<0.001). Cobb angle increased between the immediate postoperative measurement and the 6-month follow-up (17.9 versus 19.9,p=0.03). Cervical curvature changed from a 5.6° kyphosis to a 3.5° lordosis (p=0.001). Concerning lumbar lordosis, preoperative measurement was 39.7° versus 41.3° postoperatively (p=0.27). At 6-month follow-up, lumbar lordosis significantly increased to 43.6° (p=0.03). All parameters were stable at final follow-up. Correction performed by sublaminar bands is efficient for both fontal and sagittal planes. Moreover, the restoration of normal thoracic kyphosis is followed by an adaptation of the adjacent curvatures with improved cervical lordosis and lumbar lordosis.

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Patterns of coronal and sagittal deformities in adolescent idiopathic scoliosis

10.21203/rs.3.rs-42561/v3 ◽

2021 ◽

Author(s):

Trixie Mak ◽

Prudence Wing Hang Cheung ◽

Teng Zhang ◽

Jason Pui Yin Cheung

Keyword(s):

Quality Of Life ◽

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Cobb Angle ◽

Sagittal Profile ◽

Sacral Slope ◽

Pelvic Parameters ◽

Curve Magnitude ◽

Sagittal Parameters

Abstract Background: Thoracic scoliosis has been shown to be associated with hypokyphosis in adolescent idiopathic scoliosis (AIS). However, the relationship of sagittal spino-pelvic parameters with different coronal curve patterns and their influence on patient-perceived quality of life is unknown. This study aims to determine the association between coronal and sagittal malalignment in patients with AIS and to determine their effects on SRS-22r scores. Methods: A cross-sectional study was conducted on 1054 consecutive patients with AIS. The coronal Cobb angle, thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), PI-LL mismatch (PI-LL), pelvic tilt (PT), and sacral slope (SS) were measured on standing radiographs. The coronal Cobb angle (mild: 10-20°; moderate: >20-40°; severe: >40°) and PI (low: <35°; average: 35-50°; high: >50°) were divided into 3 sub-groups for comparison. Relationship between coronal curve magnitudes and sagittal parameters was studied as was their association with SRS-22r scores. Results: Low PI had smaller SS (30.1±8.3° vs 44.8±7.7°; p<0.001), PT (-0.3±8.1° vs 14.4±7.5°; p<0.001), and LL (42.0±13.2° vs 55.1±10.6°; p<0.001), negative PI-LL mismatch (-12.1±13.1° vs 4.1±10.5°; p<0.001) as compared to large PI. There were no significant relationships with PI and TK (p=0.905) or curve magnitude (p=0.431). No differences in sagittal parameters were observed for mild, moderate or severe coronal Cobb angles. SRS-22r scores only correlated with coronal Cobb angle and larger Cobb angles were negatively correlated with the function, appearance and pain domains. Conclusions: The sagittal profile for AIS is associated with the pelvic parameters especially PI but not with the coronal curve pattern. All patients have a similar TK regardless of coronal curve type. However, it appears that the coronal deformity is a greater influence on quality of life outcomes especially those >40°.

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Spine’s Sagittal Plane Curves’ Coherence with Anthropometric Parameters in Schoolchildren

Baltic Journal of Sport and Health Sciences ◽

10.33607/bjshs.v3i57.635 ◽

2018 ◽

Vol 3 (57) ◽

Author(s):

Vilma Mauricienė ◽

Kristina Bačiulienė

Keyword(s):

Body Weight ◽

Body Mass ◽

Fat Mass ◽

Lumbar Lordosis ◽

Thoracic Kyphosis ◽

Anthropometric Measurements ◽

Sagittal Profile ◽

Anthropometric Parameters ◽

Significant Difference ◽

Free Body

The aim of this study — to identify how anthropometric measurements are connected with spine sagittal curves inschoolchildren.Anthropometric and sagittal body posture measurements were performed for 405 schoolchildren, age range 10—13years. Such anthropometric measurements as body height, weight, fat mass and fat free mass were assessed. Degreesof thoracic kyphosis and lumbar lordosis as sagittal profile features were evaluated.According to the data analysis could be concluded, that coherence between anthropometric parameters and spine’ssagittal profile differs according to gender. The number of statistically significant connections between these twoparameters’ groups was greater in boys. Anthropometric measurements had greater coherence with thoracic kyphosisin comparison with lumbar lordosis. Body weight and fat mass were statistically significantly different according tokyphosis and lordosis values in boys, although fat-free body mass had no significant difference with sagittal curves’expression. Body weight, fat mass and fat-free body mass among girls were associated only with thoracic kyphosis.Keywords: thoracic kyphosis, lumbar lordosis, height, weight, fat mass.

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Problems with diagnosing early stadia of scoliosis due to discrepancies between ATR and the Cobb angle

10.21203/rs.3.rs-22512/v1 ◽

2020 ◽

Author(s):

Marek Kluszczyński ◽

Jacek Wąsik ◽

Dorota Ortenburger

Keyword(s):

Idiopathic Scoliosis ◽

Cobb Angle ◽

Lumbar Lordosis ◽

Thoracic Kyphosis ◽

Clinical Parameters ◽

Trunk Rotation ◽

X Ray ◽

False Diagnosis ◽

Cobb Method ◽

Threshold Rule

Abstract Background This research analysed discrepancies between the angle of trunk rotation (ATR) and the Cobb angle, in order to study if the commonly used 7° cut-off threshold for ATR helps diagnose scoliosis. In early stadia of scoliosis in children, ATR and the Cobb angle often disagree, increasing the risk of a false diagnosis: while the former does not suggest scoliosis, the latter does. Methods The study analysed ATR clinical parameters and the Cobb angle in the X-ray pictures of 117 (23 boys and 94 girls, aged 6–17 years) children who had not yet started treatment and whose X-ray pictures showed the Cobb angle of at least 10°, indicating idiopathic scoliosis. The degrees of lumbar lordosis and thoracic kyphosis were measured using the Saunders inclinometer, and back asymmetry was measured with Adam’s forward bend test using the Bunnell scoliometer. In the X-ray pictures, the curvature angle was plotted according to the Cobb method. The patients were stratified based on their age, and their ATRs and Cobb angles were compared. Results Although all the children had the Cobb angle over 10°, in 69 out of 117 (59%), ATR was below 7%. So, using the 7° cut-off threshold rule, scoliosis would not be diagnosed in those children. This shows that the two tests often disagree, suggesting that the 7° cut-off threshold or ATR is ineffective in diagnosing scoliosis. Conclusions To improve the method for diagnosing scoliosis based on ATR, consideration should be given to lowering the 7° ATR cut-off threshold.

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The effects of vertebral body tethering on sagittal parameters: evaluations from a 2-years follow-up

European Spine Journal ◽

10.1007/s00586-021-07076-9 ◽

2021 ◽

Author(s):

Alice Baroncini ◽

Aurelien Courvoisier ◽

Pedro Berjano ◽

Filippo Migliorini ◽

Jörg Eschweiler ◽

...

Keyword(s):

Thoracic Kyphosis ◽

Vertical Axis ◽

Sagittal Profile ◽

Sagittal Vertical Axis ◽

Lumbar Level ◽

Thoracic Level ◽

Sagittal Parameters ◽

Type 3

Abstract Introduction While the effects of VBT on coronal parameters have been investigated in various studies, this has not yet been the case for sagittal parameters. This is of particular relevance considering that VBT does not allow direct correction of the sagittal profile. Thus, we investigated the effects of VBT on sagittal parameters in patients with adolescent idiopathic scoliosis. Materials and methods Retrospective, 2-Center study. Patients who underwent VBT and presented a 2-years follow-up were included. The differences in sagittal parameters were evaluated, along with modifications of sagittal profile following Abelin-Genevois’ classification. Results Data from 86 patients were obtained. Mean Cobb angle was 52.4 ± 13.9° at thoracic level and 47.6 ± 14.3° at lumbar level before surgery, and 28.5 ± 13.6 and 26.6 ± 12.7° at the 2-year follow-up, respectively. Mean thoracic kyphosis increased from 28.3 ± 13.8 to 33 ± 13°, the lumbar lordosis (LL) was unvaried (from 47.5 ± 13.1 to 48.4 ± 13.5°), PT decreased from 9.4 ± 8.5 to 7.4 ± 6.1°, the sagittal vertical axis SVA decreased from 4.5 ± 31.4 to − 3.6 ± 27.9 mm. No kyphotic effect on LL in patients who underwent lumbar instrumentation was observed. Before surgery, 39 patients had a type 1 sagittal profile, 18 were type 2a, 14 type 2b and 15 type 3. Postoperatively, 54 were type 1, 8 were 2a, 13 were 2b and 11 were type 3. Conclusions VBT positively influences sagittal parameters and does not have a kyphotic effect on LL.

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Predictability of Coronal Curve Flexibility in Postoperative Curve Correction in Adolescent Idiopathic Scoliosis: The Effect of the Sagittal Profile

Global Spine Journal ◽

10.1177/2192568219877862 ◽

2019 ◽

Vol 10 (3) ◽

pp. 303-311 ◽

Cited By ~ 1

Author(s):

Søren Ohrt-Nissen ◽

Hideki Shigematsu ◽

Jason Pui Yin Cheung ◽

Keith D. K. Luk ◽

Dino Samartzis

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Cobb Angle ◽

Thoracic Kyphosis ◽

Clinical Decision Making ◽

Sagittal Profile ◽

Curve Correction ◽

Sagittal Vertical Axis ◽

Flexibility Index

Study Design: Retrospective cohort study. Objectives: To assess how the thoracic kyphosis affects the ability of the fulcrum bending radiograph (FBR) to predict the coronal thoracic curve correction. Methods: A retrospective study of prospectively collected data was conducted of 107 consecutive patients with thoracic adolescent idiopathic scoliosis (AIS) treated with a standard screw-fixation protocol. Radiographic variables were assessed preoperatively and at 2-year follow-up. Curve flexibility was determined based on the FBR and the Fulcrum Bending Flexibility Index (FBCI). Radiographic variables included preoperative Cobb angle, T5-T12 kyphosis, T12-S1 lordosis, sagittal vertical axis, list, T1-T12 length, truncal shift, and radiographic shoulder height. Patients were also categorized as hypo-, normo-, or hyperkyphotic. Results: Based on multivariate modeling, an increase in FBR Cobb angle and thoracic kyphosis were significantly associated with an increase in FBCI (increased mismatch between the FBR and postoperative Cobb angles) at 2-year follow-up ( P < 0.001). In patients with hyperkyphosis, a longer instrumented length existed despite similar curve size and shorter curve length than the hypo- and normokyphotic groups. Based on these findings, we developed a new predictive postoperative curve correction index, known as the Multiprofile Flexibility Index (MFI). Conclusions: Our results show that an increase in preoperative thoracic kyphosis is associated with an increased difference between the preoperative coronal curve flexibility and the postoperative coronal curve correction. Our findings broaden the understanding of curve flexibility and indicate that selection of fusion levels may need to take into consideration the sagittal profile to improve clinical decision making and optimize outcome.

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