A purpose-design computational method for estimation of plane of maximum curvature in Adolescent Idiopathic Scoliosis

2021 ◽  
Author(s):  
MS Wong ◽  
HD Wu
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Vertical Plane ◽  
Orientation Angle ◽  
Vertical Axis ◽  
Ct Images ◽  
Computational Method ◽  
Spinal Curvature ◽  
Maximum Curvature ◽  
Bland Altman Method

Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional (3D) deformity, and the plane of maximum curvature (PMC) is proposed to reflect these clinical features, which refers to a vertical plane presenting the maximum projected spinal curvature and its parameters include the PMC Cobb and orientation (angle between PMC and sagittal planes). This study aimed to develop a computational method (CM) for PMC estimation. Twenty-nine patients with AIS and computed tomography (CT) images were recruited. For CT, PMC was determined by rotating a vertical plane about its vertical axis with 5° increment until the maximum Cobb angle was measured. For CM, PMC was estimated via identifying the eight points (the corner points of the superior and inferior endplates of the upper and lower end-vertebrae respectively) in the coronal and lateral CT images. Two experienced raters repeated the PMC estimation three times with one-week interval. The intra-class correlation coefficient (ICC) and Bland-Altman method were used for statistical analysis. Twenty-seven right thoracic curves (RTs) (mean Cobb: 46.1°±12.4°) and 23 left thoracolumbar/lumbar (LTLs/LLs) (mean Cobb: 30.6°±11.1°) were analysed. The intra- and inter-rater ICC values were >0.91 and 0.84 in RTs and LTLs/LLs, respectively. The PMCs obtained from the CM and CT were showed good agreement was also observed between the PMCs obtained from the two methods according to ICC (>0.90) and Bland-Altman method assessments. This purpose-design computational method could provide reliable and valid estimation of PMCs for AIS, which has potential to be used as an alternative for 3D assessment.

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 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>

scholarly journals Revision Strategies for Harrington Rod Instrumentation: Radiographic Outcomes and Complications

2020 ◽  
pp. 219256822096075
Author(s):  
Philip K. Louie ◽  
Sravisht Iyer ◽  
Krishn Khanna ◽  
Garrett K. Harada ◽  
Alina Khalid ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Revision Surgery ◽  
Lumbar Lordosis ◽  
Pelvic Incidence ◽  
Vertical Axis ◽  
Sagittal Vertical Axis ◽  
Radiographic Outcomes ◽  
Harrington Rod

Study Design: Retrospective case series. Objective: The purpose of this study is to evaluate the clinical and radiographic outcomes following revision surgery following Harrington rod instrumentation. Methods: Patients who underwent revision surgery with a minimum of 1-year follow-up for flatback syndrome following Harrington rod instrumentation for adolescent idiopathic scoliosis were identified from a multicenter dataset. Baseline demographics and intraoperative information were obtained. Preoperative, initial postoperative, and most recent spinopelvic parameters were compared. Postoperative complications and reoperations were subsequently evaluated. Results: A total of 41 patients met the inclusion criteria with an average follow-up of 27.7 months. Overall, 14 patients (34.1%) underwent a combined anterior-posterior fusion, and 27 (65.9%) underwent an osteotomy for correction. Preoperatively, the most common lower instrumented vertebra (LIV) was at L3 and L4 (61%), whereas 85% had a LIV to the pelvis after revision. The mean preoperative pelvic incidence–lumbar lordosis mismatch and C7 sagittal vertical axis were 23.7° and 89.6 mm. This was corrected to 8.1° and 28.9 mm and maintained to 9.04° and 34.4 mm at latest follow-up. Complications included deep wound infection (12.2%), durotomy (14.6%), implant related failures (14.6%), and temporary neurologic deficits (22.0%). Eight patients underwent further revision surgery at an average of 7.4 months after initial revision. Conclusions: There are multiple surgical techniques to address symptomatic flatback syndrome in patients with previous Harrington rod instrumentation for adolescent idiopathic scoliosis. At an average of 27.7 months follow-up, pelvic incidence–lumbar lordosis mismatch and C7 sagittal vertical axis can be successfully corrected and maintained. However, complication and reoperation rates remain high.

scholarly journals Long-term effects of the Chêneau brace on coronal and sagittal alignment in adolescent idiopathic scoliosis

2015 ◽  
Vol 23 (4) ◽  
pp. 505-509 ◽  
Author(s):  
Ming-Qiao Fang ◽  
Chong Wang ◽  
Guang-Heng Xiang ◽  
Chao Lou ◽  
Nai-Feng Tian ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Sagittal Alignment ◽  
Vertical Axis ◽  
Sacral Slope ◽  
Long Term Effects ◽  
Sagittal Vertical Axis ◽  
Pelvic Parameters

OBJECT The aim of the present study was to retrospectively evaluate progressive correction of coronal and sagittal alignment and pelvic parameters in patients treated with a Chêneau brace. METHODS Thirty-two patients with adolescent idiopathic scoliosis (AIS) were assessed before initiation of bracing treatment and at the final follow-up. Each patient underwent radiological examinations, and coronal, sagittal, and pelvic parameters were measured. RESULTS No statistically significant modification of the Cobb angle was noted. The pelvic incidence remained unchanged in 59% of the cases and increased in 28% of the cases. The sacral slope decreased in 34% of the cases but remained unchanged in 50%. Thoracic kyphosis and lumbar lordosis were significantly decreased, whereas the sagittal vertical axis was significantly increased from a mean of -44.0 to -30.2 mm (p = 0.02). The mean pelvic tilt increased significantly from 4.5° to 8.3° (p = 0.002). CONCLUSIONS The Chêneau brace can be useful for preventing curvature progression in patients with AIS. However, the results of this study reveal high variability in the effect of brace treatment on sagittal and pelvic alignment. Treatment with the Chêneau brace may also influence sagittal global balance.

Observer Variation in Assessing Spinal Curvature and Skeletal Development in Adolescent Idiopathic Scoliosis

Spine ◽  
1988 ◽  
Vol 13 (12) ◽  
pp. 1371-1377 ◽  
Author(s):  
MARK S. GOLDBERG ◽  
BENOIT POITRAS ◽  
NANCY E. MAYO ◽  
HUBERT LABELLE ◽  
RICHARD BOURASSA ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Skeletal Development ◽  
Observer Variation ◽  
Spinal Curvature

Impact of Scoliosis Severity on Functional Capacity in Patients With Adolescent Idiopathic Scoliosis

2018 ◽  
Vol 30 (2) ◽  
pp. 243-250 ◽  
Author(s):  
Bruna M.A. Saraiva ◽  
Geferson S. Araujo ◽  
Evandro F. Sperandio ◽  
Alberto O. Gotfryd ◽  
Victor Z. Dourado ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Tidal Volume ◽  
Functional Capacity ◽  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Physiological Responses ◽  
Spinal Curvature ◽  
Control Group ◽  
Walk Test

Purpose: The aim of this study is to evaluate the walked distance and physiological responses during incremental shuttle walk test in patients with different degrees of adolescent idiopathic scoliosis (AIS). Methods: We evaluated 20 healthy teenagers and 46 patients with AIS; they were divided into 2 groups: AIS > 45° and AIS < 45°. The volunteers performed an incremental shuttle walk test, and the following physiological responses were quantified: oxygen consumption, tidal volume, ventilation, and the incremental shuttle walked distance. Respiratory muscle strength was quantified, pulmonary function test was performed, and the forced vital capacity and expiratory volume in the first second were obtained. Results: Patients with AIS > 45° presented significant reduced incremental shuttle walked distance compared with the AIS < 45° and control group [447 (85), 487 (95), and 603 (85), respectively]. Patients with AIS also showed reduced forced vital capacity (P = .001) and expiratory volume in the first second (P = .005) compared with control group. Moderate correlations between forced vital capacity (r = −.506) and tidal volume (r = −.476) with scoliosis angles were found. Conclusions: The incremental shuttle walk test was capable of identifying reduced functional capacity in patients with different degrees of AIS. Moreover, the severity of spinal curvature may exert influence on ventilatory and metabolic variables.

scholarly journals Cross-validation of ultrasound imaging in adolescent idiopathic scoliosis

2020 ◽  
Author(s):  
Steven de Reuver ◽  
Rob C. Brink ◽  
Timothy T. Y. Lee ◽  
Yong-Ping Zheng ◽  
Frederik J. A. Beek ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Ultrasound Imaging ◽  
Linear Regression Analysis ◽  
Spinal Curvature ◽  
Validation Group ◽  
Lifetime Cancer Risk ◽  
Spinous Processes ◽  
Spinal Ultrasound

Abstract Purpose Adolescent idiopathic scoliosis (AIS) patients are exposed to 9–10 times more radiation and a fivefold increased lifetime cancer risk. Radiation-free imaging alternatives are needed. Ultrasound imaging of spinal curvature was shown to be accurate, however, systematically underestimating the Cobb angle. The purpose of this study is to create and cross-validate an equation that calculates the expected Cobb angle using ultrasound spinal measurements of AIS patients. Methods Seventy AIS patients with upright radiography and spinal ultrasound were split randomly in a 4:1 ratio to the equation creation (n = 54) or validation (n = 16) group. Ultrasound angles based on the spinous processes shadows were measured automatically by the ultrasound system (Scolioscan, Telefield, Hong Kong). For thoracic and lumbar curves separately, the equation: expected Cobb angle = regression coefficient × ultrasound angle, was created and subsequently cross-validated in the validation group. Results Linear regression analysis between ultrasound angles and radiographic Cobb angles (thoracic: R2 = 0.968, lumbar: R2 = 0.923, p < 0.001) in the creation group resulted in the equations: thoracic Cobb angle = 1.43 × ultrasound angle and lumbar Cobb angle = 1.23 × ultrasound angle. With these equations, expected Cobb angles in the validation group were calculated and showed an excellent correlation with the radiographic Cobb angles (thoracic: R2 = 0.959, lumbar: R2 = 0.936, p < 0.001). The mean absolute differences were 6.5°–7.3°. Bland–Altman plots showed good accuracy and no proportional bias. Conclusion The equations from ultrasound measurements to Cobb angles were valid and accurate. This supports the implementation of ultrasound imaging, possibly leading to less frequent radiography and reducing ionizing radiation in AIS patients.

scholarly journals Automatic Vertebrae Localization and Spine Centerline Extraction in Radiographs of Patients with Adolescent Idiopathic Scoliosis

2021 ◽  
Author(s):  
Gunarajulu Renganathan ◽  
Navin Manaswi ◽  
Ionuţ Ghionea ◽  
Sasa Cukovic
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Frontal Plane ◽  
Intervertebral Discs ◽  
High Variability ◽  
Spinal Curvature ◽  
Anatomical Landmarks ◽  
Spinal Alignment ◽  
Centerline Extraction ◽  
Correction Strategies

Adolescent Idiopathic Scoliosis (AIS) is lifetime disorder indicated by the abnormal spinal curvature, and it is usually detected in children and adolescents. Traditional radiographic assessment of scoliosis is time-consuming and unreliable due to high variability in images and manual interpretation. Vertebrae localization and centerline extraction from a biplanar X-ray is essential for pathological diagnosis, treatment planning, and decision making. The aim of this paper is to develop a fully automated framework to provide correct evaluation of anatomical landmarks and to extract vertebral and intervertebral discs’ centroids. By knowing coordinates of each centroid, developed framework will estimate 2D deformity curve (centerline) called Middle Spinal Alignment (MSA) in frontal plane. By analyzing the MSA lines and deformity segments, many deformity parameters can be calculated which include vertebral transpositions, Cobb angles, apex vertebra position, etc., for planning spinal correction strategies and monitoring.

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