More severe thoracic idiopathic scoliosis is associated with a greater three-dimensional loss of thoracic kyphosis

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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Three-Dimensional Analysis of Right Thoracic Idiopathic Scoliosis

Spine ◽

10.1097/00007632-198405000-00009 ◽

1984 ◽

Vol 9 (4) ◽

pp. 377-381 ◽

Cited By ~ 25

Author(s):

ARTHUR A. DE SMET ◽

MARC A. ASHER ◽

LARRY T. COOK ◽

JAMES E. GOIN ◽

HELEN G. SCHEUCH ◽

...

Keyword(s):

Idiopathic Scoliosis ◽

Dimensional Analysis ◽

Three Dimensional ◽

Thoracic Idiopathic Scoliosis

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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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The correlations between the anchor density and the curve correction of adolescent idiopathic scoliosis surgery

BMC Musculoskeletal Disorders ◽

10.1186/s12891-019-2844-1 ◽

2019 ◽

Vol 20 (1) ◽

Cited By ~ 1

Author(s):

Yu-Cheng Yeh ◽

Chi-Chien Niu ◽

Lih-Huei Chen ◽

Wen-Jer Chen ◽

Po-Liang Lai

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Thoracic Kyphosis ◽

Three Dimensional ◽

High Density ◽

Scoliosis Surgery ◽

Low Density ◽

Curve Correction ◽

Kyphosis Correction ◽

Positive Correlations

Abstract Background The optimal anchor density in adolescent idiopathic scoliosis (AIS) surgery to achieve good curve correction remains unclear. The purpose of the study is to analyze the correlations between three-dimensional curve correction and anchor density in the pedicle screw-based posterior fusion of AIS. Methods One hundred and twenty-seven AIS patients receiving primary posterior fusion with pedicle screw instrumentation were retrospectively reviewed. Anchor density (AD) was defined as the screws number per fused spinal segment. The correlations between three-dimensional curve correction radiographic parameters and anchor density were analyzed with subgroup analysis based on different curve types, curve magnitudes, and curve flexibilities. The differences of curve correction parameters between the low-density (AD ≤1.4), middle-density (1.4 < AD ≤1.7) and high-density (AD > 1.7) groups were also calculated. Independent t-test, analysis of variance (ANOVA), and Pearson’s correlation coefficient were used for statistical analysis. Results There were no correlations between the anchor density and the coronal curve correction or apical vertebral rotation (AVR) correction. In the sagittal plane, mild positive correlations existed between anchor density and thoracic kyphosis correction in all patients (r = 0.27, p = 0.002). Subgroup analysis revealed similar mild positive correlations in Lenke 1 (r = 0.31, p = 0.02), Lenke 1–3 (r = 0.27, p = 0.01), small curves (40°-60°, r = 0.38, p < 0.001), and flexible curves (flexibility > 40%, r = 0.34, p = 0.01). There were no differences between low-density (mean 1.31), middle-density (mean 1.55), and high-density (mean 1.83) in terms of coronal or axial curve correction parameters. Low-density group has longer fused level (mean difference 2.14, p = 0.001) and smaller thoracic kyphosis correction (mean difference 9.25°, p = 0.004) than high-density group. Conclusion In our study, the anchor density was not related to coronal or axial curve corrections. Mild positive correlations with anchor density were found in thoracic kyphosis correction, especially in patients with smaller and flexible curves. Low anchor density with longer fusion level achieves similar curve corrections with middle or high anchor density in adolescent idiopathic scoliosis surgery.

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Flexibility of the thoracic curve and three-dimensional thoracic kyphosis can predict pulmonary function in nonoperatively treated adult patients with adolescent idiopathic scoliosis

Journal of Orthopaedic Science ◽

10.1016/j.jos.2019.06.015 ◽

2020 ◽

Vol 25 (4) ◽

pp. 551-556

Author(s):

Masayuki Ohashi ◽

Kei Watanabe ◽

Toru Hirano ◽

Kazuhiro Hasegawa ◽

Keiichi Katsumi ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Pulmonary Function ◽

Thoracic Kyphosis ◽

Three Dimensional ◽

Adult Patients ◽

Thoracic Curve

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Three-Dimensional Analysis of Initial Brace Correction in the Setting of Adolescent Idiopathic Scoliosis

Journal of Clinical Medicine ◽

10.3390/jcm8111804 ◽

2019 ◽

Vol 8 (11) ◽

pp. 1804 ◽

Cited By ~ 2

Author(s):

Haidara Almansour ◽

Wojciech Pepke ◽

Thomas Bruckner ◽

Bassel G. Diebo ◽

Michael Akbar

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Thoracic Kyphosis ◽

Healthcare Providers ◽

Three Dimensional ◽

Transverse Plane ◽

Sagittal Profile ◽

Spinopelvic Parameters ◽

Axial Vertebral Rotation ◽

The Impact

The three-dimensional nature of adolescent idiopathic scoliosis (AIS) necessitates a tridimensional assessment and management. Bracing constitutes the mainstay conservative treatment for mild adolescent idiopathic scoliosis. In the literature hitherto, there has been uncertainty regarding the behavior of the spine, pelvis, and vertebral orientations in the context of bracing, especially in the transverse plane. This poses a challenge to healthcare providers, patients, and their families, as brace treatment, although not as invasive as surgery, is laden with medical and psychological complications and could be considered traumatizing. Hence, a thorough understanding of initial three-dimensional spinal behavior in the context of bracing is important. The purpose of this retrospective study was to investigate the immediate 3D impact of Chêneau-type brace. Thirty-eight patients with AIS undergoing Chêneau-type bracing were included. Patients were stratified according to their structural curve topography into thoracic, thoracolumbar, and lumbar groups. 3D reconstruction of the spine using a dedicated biplanar stereoradiography software with and without the brace was performed. The examined anthropometric radiographic measures were pre- to in-brace variations and differences of spinopelvic parameters and vertebral orientations in the coronal, sagittal, and transverse planes. The complex impact of the Chêneau-type brace on different curves in three planes was delineated. In the coronal plane, the Cobb angle was significantly decreased in all types of curves, and the coronal tilt correction was concentrated in specific segments. The impact of the brace in this study on the sagittal profile was variable, including the loss of thoracic kyphosis and lumbar lordosis. In the transverse plane, an axial vertebral rotation change and detorsion above the apex occurred in the thoracolumbar curves. The results from this exploratory study could shed some light on the initial 3D spinal behavior in the context of bracing and may be of beneficial for treating physicians and brace makers.

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