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

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.

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

2019 ◽  
Vol 8 (11) ◽  
pp. 1804 ◽  
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.

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

2017 ◽  
Vol 11 (5) ◽  
pp. 770-779 ◽  
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><p>Retrospective analysis.</p></sec><sec><title>Purpose</title><p>Our hypothesis is that the surgical correction of adolescent idiopathic scoliosis (AIS) maintains normal sagittal alignment as compared to age-matched normative adolescent population.</p></sec><sec><title>Overview of Literature</title><p>Sagittal spino-pelvic alignment in AIS has been reported, however, whether corrective spinal fusion surgery re-establishes normal alignment remains unverified.</p></sec><sec><title>Methods</title><p>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.</p></sec><sec><title>Results</title><p>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>&lt;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.</p></sec><sec><title>Conclusions</title><p>Surgical correction of the coronal plane in AIS patients preserves sagittal and spino-pelvic alignment as compared to age-matched asymptomatic adolescents.</p></sec>

Three-dimensional analysis of the sagittal profile in surgically treated Lenke 5 curves in adolescent idiopathic scoliosis

2020 ◽  
Vol 8 (6) ◽  
pp. 1287-1294
Author(s):  
Kaiying Shen ◽  
R. Carter Clement ◽  
Burt Yaszay ◽  
Tracey Bastrom ◽  
Vidyadhar V. Upasani ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Sagittal Profile

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

2019 ◽  
Vol 10 (3) ◽  
pp. 303-311 ◽  
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.

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

2019 ◽  
Vol 20 (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.

scholarly journals Cervical sagittal alignment in patients with adolescent idiopathic scoliosis: is it corrected by surgery?

2018 ◽  
Vol 21 (3) ◽  
pp. 292-301 ◽  
Author(s):  
Jae Hwan Cho ◽  
Chang Ju Hwang ◽  
Young Hyun Choi ◽  
Dong-Ho Lee ◽  
Choon Sung Lee
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Clinical Outcomes ◽  
Thoracic Kyphosis ◽  
Sagittal Alignment ◽  
Corrective Surgery ◽  
Related Factors ◽  
Radiological Parameter ◽  
Number Of Patients ◽  
Cervical Sagittal Alignment

OBJECTIVECervical sagittal alignment (CSA) is related to function and quality of life, but it has not been frequently studied in patients with adolescent idiopathic scoliosis. This study aimed to reveal the change in CSA following corrective surgery, compare the cervical sagittal parameters according to curve types, and assess related factors for postoperative aggravation of CSA.METHODSThe authors studied 318 consecutive patients with adolescent idiopathic scoliosis who underwent corrective surgery at a single center. Occiput–C2 and C2–7 lordosis, C2–7 sagittal vertical axis (SVA), T-1 slope, thoracic kyphosis, and lumbar sagittal profiles were measured preoperatively and postoperatively. Scoliosis Research Society Outcomes Questionnaire (SRS-22) scores were used as clinical outcomes. Each radiological parameter was compared preoperatively and postoperatively according to curve types (double major, single thoracic, and double thoracic curves). Patients were grouped based on preoperative CSA: the lordotic group (group L) and the kyphotic group (group K). Each radiological parameter was compared between the groups. Related factors for postoperative aggravation of CSA were assessed using multivariate logistic analysis.RESULTSOf the total number of patients studied, 67.0% (213 of 318) and 54.4% (173 of 318) showed cervical kyphotic alignment preoperatively and postoperatively, respectively. C2–7 lordosis increased (from −5.8° to −1.1°; p < 0.001) and C2–7 SVA decreased (from 24.2 to 20.0 mm; p < 0.001) postoperatively regardless of curve types. Although group K showed improvement in C2–7 lordosis (from −12.7° to −4.8°; p < 0.001), group L showed no difference (from 9.0° to 6.9°; p = 0.115) postoperatively. Clinical outcomes were not related to the degree of cervical kyphosis in this cohort. C2–7 lordosis (p < 0.001) and pelvic tilt (p = 0.019) were related to postoperative aggravation of CSA.CONCLUSIONSRegardless of the trend of improvement in CSA, many patients (54.4%) still showed cervical kyphotic alignment postoperatively. C2–7 lordosis and C2–7 SVA improved postoperatively in all curve types. However, postoperative changes in C2–7 lordosis showed different results based on preoperative CSA, which could be related to T-1 slope and thoracic kyphosis. However, clinical outcomes showed no difference based on CSA in this study cohort. Greater C2–7 lordosis and proximal thoracic curve preoperatively were risk factors for postoperative aggravation of CSA (p < 0.001 and p = 0.019, respectively).

scholarly journals Improved restoration of thoracic kyphosis using a rod construct with differentiated rigidity in the surgical treatment of adolescent idiopathic scoliosis

2017 ◽  
Vol 43 (4) ◽  
pp. E6 ◽  
Author(s):  
Søren Ohrt-Nissen ◽  
Casper Dragsted ◽  
Benny Dahl ◽  
John A. I. Ferguson ◽  
Martin Gehrchen
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Thoracic Kyphosis ◽  
Sagittal Alignment ◽  
Group Versus ◽  
Secondary Outcome ◽  
Curve Correction ◽  
Caudal Portion ◽  
Significant Difference ◽  
The Mean

OBJECTIVEThe objective of this study was to compare postoperative sagittal alignment among 3 rod constructs with different rigidity profiles.METHODSThis was a dual-center retrospective cohort study involving 2 consecutive cohorts in which patients were surgically treated for adolescent idiopathic scoliosis. Lenke Type 5 curves were excluded. Patients were operated on with all–pedicle screw instrumentation using 3 different rod constructs. The first group was operated on using a hybrid construct (HC) consisting of a normal circular rod on the convex side and a beam-like rod (BR) on the concave side. The second group was operated on with a standard construct (SC) using bilateral BRs in the full length of the fusion. The third group was operated on with a modified construct (MC). The modified rods have a beam-like shape in the caudal portion, but in the cranial 2 or 3 fusion levels the rod transitions to a circular shape with a smaller anteroposterior diameter. Radiographs were analyzed preoperatively and at the first postoperative follow-up (range 1–8 weeks). The primary outcome was pre- to postoperative change in thoracic kyphosis (TK), and the secondary outcome was the ability to achieve postoperative TK within the normal range.RESULTSThe HC, SC, and MC groups included 23, 70, and 46 patients, respectively. The 3 groups did not differ significantly in preoperative demographic or radiographic parameters. The mean ± standard deviation of the preoperative main curve was 60.7° ± 12.6°, and the mean of curve correction was 62.9% ± 10.4% with no significant difference among groups (p ≥ 0.680). The groups did not differ significantly in coronal balance or proximal or thoracolumbar curve correction (p ≥ 0.189). Mean postoperative TK was 23.1° ± 6.3°, 19.6° ± 7.6°, and 23.4° ± 6.9° in the HC, SC and MC groups, respectively (p = 0.013), and the mean change in TK was −3.5° ± 11.3°, −7.1° ± 11.6°, and 0.1° ± 10.9°, respectively (p = 0.005). The MC group had significantly higher postoperative TK and less loss of TK compared with the SC group (p ≤ 0.018). Postoperative TK ≤ 10° was found in 12 patients (17%) in the SC group, 1 patient (5%) in the HC group, and 1 patient (2%) in the MC group (p = 0.021). There were no differences in proximal alignment, thoracolumbar alignment, or sagittal vertical axis (p ≥ 0.249). Lumbar lordosis was 58.9° ± 11.2° in the HC group versus 52.0° ± 1.3° and 55.0° ± 11.0° and the SC and MC groups, respectively (p = 0.040).CONCLUSIONSIn the 3 rod constructs with different rigidity profiles, significantly better restoration of kyphosis was achieved with the use of bilateral modified rods compared with bilateral standard rods. In the MC and HC groups, the rate of severe postoperative hypokyphosis was significantly lower than in the SC group. This is the first study to describe the clinical use of a rod with a reduced proximal diameter and show marked radiographic improvement in sagittal alignment.

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