Validation of a Generally Applicable Method for the Characterization of Scoliotic Deformities and Sagittal Spinal Curvatures (original) (raw)
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New Method of Scoliosis Assessment
Spine, 2011
Study Design. A new method for nonradiographic evaluation of scoliosis was independently compared with the Cobb radiographic method, for the quantifi cation of scoliotic curvature. Objective. To develop a protocol for computerized photogrammetry, as a nonradiographic method, for the quantifi cation of scoliosis, and to mathematically relate this proposed method with the Cobb radiographic method. Summary of Background Data. Repeated exposure to radiation of children can be harmful to their health. Nevertheless, no nonradiographic method until now proposed has gained popularity as a routine method for evaluation, mainly due to a low correspondence to the Cobb radiographic method. Methods. Patients undergoing standing posteroanterior full-length spine radiographs, who were willing to participate in this study, were submitted to dorsal digital photography in the orthostatic position with special surface markers over the spinous process, specifi cally the vertebrae C7 to L5. The radiographic and photographic images were sent separately for independent analysis to two examiners, trained in quantifi cation of scoliosis for the types of images received. The scoliosis curvature angles obtained through computerized photogrammetry (the new method) were compared to those obtained through the Cobb radiographic method. Results. Sixteen individuals were evaluated (14 female and 2 male). All presented idiopathic scoliosis, and were between 21.4 ± 6.1 years of age; 52.9 ± 5.8 kg in weight; 1.63 ± 0.05 m in height, with a body mass index of 19.8 ± 0.2. There was no statistically signifi cant difference between the scoliosis angle measurements obtained in the comparative analysis of both methods, and a mathematical relationship was formulated between both methods.
Radiation-free quantitative assessment of scoliosis: a multi center prospective study
European Spine Journal, 2007
Accurate quantitative measurements of the spine are essential for deformity diagnosis and assessment of curve progression. There is much concern related to the multiple exposures to ionizing radiation associated with the Cobb method of radiographic measurement, currently the standard procedure for diagnosis and follow-up of the progression of scoliosis. In addition, the Cobb method relies on 2-D analysis of a 3-D deformity. The aim of this prospective study was to investigate the clinical value of Ortelius800TM that provides a radiation-free method for scoliosis assessment in three planes (coronal, sagittal, apical), with simultaneous automatic calculation of the Cobb angle in both coronal and sagittal views. Analysis of the clinical value of the device for assessing spinal deformities was performed on patients with adolescent idiopathic scoliosis, deformity angles ranging from 10° to 48°. Correlation between Cobb angles measured manually on standard erect posteroanterior radiographs and those calculated by Ortelius800TM showed an absolute difference between the measurements to be significantly less than ± 5° for coronal measurements and significantly less than ± 6° for sagittal measurements indicating good correlation between the two methods. The measurements from four independent sites and six independent examiners were not significantly different. We found the novel clinical tool to be reliable for following mild and moderate idiopathic curves in both coronal and sagittal planes, without exposing the patient to ionizing radiation. Considering the need for further validation of this new method, any change in treatment protocol should still be based on radiographic control.
Assessment of scoliotic deformity from back shape asymmetry using an improved mathematical model
Clinical Biomechanics, 1996
Objective. The objective of the study was to improve with respect to accuracy and smoothness the three-dimensional model of the spinal midline which has been calculated from rasterstereographic back surface data. Design. A new mathematical model using frequency-modulated sine curves has been applied to existing rasterstereographic and radiographic data in an in vivo study. Background. Analysis of back shape (measured by rasterstereography) enables a threedimensional model of the spinal midline to be calculated. The model is based on the so-called symmetry line which coincides approximately with the line of the spinous processes. In addition the surface rotation on the symmetry line is taken as an estimate for vertebral axial rotation in scoliosis. Methods. Four hundred and seventy-eight pairs of radiographs and rasterstereographs of scoliotic patients have been evaluated and compared using the new model. The radiographs were digitized manually, delivering curves of lateral deviation and vertebral rotation. Analysis of back shape from the rasterstereographs delivers a three-dimensional model of the spinal midline, the frontal projection of which is to be compared with the radiographic curve. Likewise, vertebral rotation and surface rotation are compared. Results. The use of frequency-modulated sine curves improved the results as compared to the existing procedure with respect to prediction accuracy of lateral deviation (typically from o, = 4.6 mm to o, = 4.0 mm, P< IO-"). The prediction of axial rotation was not significantly improved (a, 2 3.8"). In addition, the smoothness of the curves is considerably improved. The prediction accuracy proved to be independent of the scoliosis type as represented by apex height (r =-0.09. + 0.03). Conclusion. The use of frequency-modulated sine curves improves significantly the accuracy and smoothness of the spinal model curves. Relevance Accuracy and reliability of data obtained from back shape analysis are of crucial importance for routine clinical application. The presented method delivers a three-dimensional model of the spinal midline which is superior to previous results with respect to accuracy (as compared to radiographs) and quality of curve shape. Thus the usefulness of the method for follow-up studies and possible reduction of radiographs is enhanced.
Comparison of two- and three-dimensional measurement of the Cobb angle in scoliosis
International Orthopaedics, 2016
Purpose The Cobb angle as an objective measure is used to determine the progression of deformity, and is the basis in the planning of conservative and surgical treatment. However, studies have shown that the Cobb angle has two limitations: an inter-and intraobserver variability of the measurement is approximately 3-5 degrees, and high variability regarding the definition of the end vertebra. Scoliosis is a three-dimensional (3D) pathology, and 3D pathologies cannot be completely assessed by two-dimensional (2D) methods, like 2D radiography. The objective of this study was to determine the intraobserver and interobserver reliability of end vertebra definition and Cobb angle measurement using X-rays and 3D computer tomography (CT) reconstructions in scoliotic spines. Methods To assess interoberver variation the Cobb angle and the end vertebra were assessed by five observers in 55 patients using X-rays and 3D CT reconstructions. Definition of end vertebra and measurement of the Cobb angle was repeated two times with a three-week interval. Intraclass correlation coefficients (ICC) were used to determine the interobserver and intraobserver reliabilities. 95% prediction limits were provided for measurement errors. Results Intraclass correlation coefficient (ICC) showed excellent reliability for both methods. The measured Cobb angle was on average 9.2 degrees larger in the 3D CT group (72.8°, range 30-144) than on 2D radiography (63.6°, range 24-152). Conclusions In scoliosis treatment it is very essential to determine the curve magnitude, which is larger in a 3D measurement compared to 2D radiography.
The method for measurement of the three-dimensional scoliosis angle from standard radiographs
BMC Musculoskeletal Disorders, 2020
Background: Three-dimensional idiopathic scoliosis cannot be accurately assessed with the aid of a single plane parameterthe Cobb angle. We propose a novel method for evaluating the three-dimensional (3D) pattern of scoliosis based on two X-rays (PA and lateral). The proposed method consists of the measurements of the angles between the upper endplate of the upper-end vertebra and the lower endplate of the lower-end vertebra (3D scoliosis angle). Methods: The 3D-angles of thirty scoliosis curves were measured with either computed tomography (CT) or digitally reconstructed radiographs (DRRs): PA and lateral. CT was used as a reference. In the case of CT, the 3D angle was calculated based on the coordinates of three points situated on the upper endplate and those of three points situated on the lower endplate of the scoliosis curve. In the case of the DRR, the 3D angle was calculated using the four-angle method: the angles formed by the endplates of the curve with the transverse plane. The results were tested with the Student's t-test, and the agreement of measurements was tested with the intraclass correlation coefficient. Results: There was no significant difference between the 3D-angle measurements obtained with DRRs versus CT, p > 0.05. There was, however, a significant difference between the 3D-scoliosis angle and the Cobb angle measurements performed based on the X-rays. The reproducibility and reliability of 3D angle measurements were high. Conclusions: Based on two standard radiographs, PA and lateral, it is possible to calculate the 3D scoliosis angle. The proposed method facilitates 3D-scoliosis assessment without the use of sophisticated devices. Considering the 3D nature of AIS, the 3D parameters of the spine may help to apply a more effective treatment and estimate a more precise prognosis for patient with scoliosis.
Trends in Medicine, 2019
Study design: A cross-sectional study Summary and background data: Both Scoliometer and Debrunner's Kyphometer are validated and widely accepted as surface non-invasive, non-radiating measurement instruments for school screening programs for detection and measurement of scoliosis, thoracic kyphosis and lumbar lordosis. Objectives of the study: The authors have questioned if the prevalence of scoliosis and its distribution among gender and spinal levels has changed in the last 20 years; and if the additional measurement of sagittal spinal curvatures is of great importance just like the scoliosis is. Methods: This cross-sectional observational study was conducted in 2016 in a randomly selected school population in a metropolitan town in the southwestern Europe. In 897 adolescents, aged 12-14 years the authors measured both coronal and sagittal spinal curvatures using the scoliometer to measure scoliosis and the Debrunner kyphometer to measure thoracic kyphosis and lumbar lordosis. Previously validated mathematical formulae were used to estimate with high accuracy the predicted Cobb angle. Leg discrepancy was evaluated and correlated with scoliosis. Results: The reliability of measurement with the Debrunner's kyphometer and Scoliometer was high. There were 124 (13.8%) subjects with scoliosis curve-ATR/ value of ≥2 o. The 99.94% were single-level curves, and 0.06% double curves. The right thoracic curve was the most frequent (49%), followed by the right thoracolumbar (19%); left lumbar (12%); left thoracic (8%); right lumbar (6%) and left thoracolumbar (6%). Girls showed higher prevalence than boys in right thoracic (P=0.009) and right thoracolumbar (P= 0.014) curves. In contrary, in 53 subjects (40 girls, 13 boys) with ATR>5 o : no significant gender-related difference and right to left side localization of scoliosis was disclosed; there were 4 (7.5%) individuals with right thoracic ATR: 9 (17%) with left thoracic; 13 (25%) right thoracolumbar; 4 (7.5%) left thoracolumbar; 2 (4%) right lumbar and 10 (19%) left lumbar. There was a statistically significant positive correlation between right lumbar ATR and ipsilateral leg shortening (P=0.000). These findings are within previous similar school screening reports in this country in the last 20 years. Thoracic kyphosis increases linearly with lumbar lordosis. Boys showed greater thoracic kyphosis and less lumbar lordosis than girls. Fourteen (0.15%) individuals with Kyphometer values ≥55 o were sent for radiological examination. Fifty three (5.9%) subjects (3.2% boys and 8.2% girls) with ATR ≥5° were sent for radiological examination. Conclusions: The authors recommend to physicians engaged in scoliosis screening programs to use the Debrunner Kyphometer and Scoliometer together with the mathematic formulas for accurate Cobb angle measurement. We believe that this method will reduce the cost of school screening programs, the over diagnosis, and the unnecessary exposure to radiation of young population in the future.
BMC Musculoskeletal Disorders
Introduction The three dimensional deformation of the spine in scoliosis is specific for a given child with regard to the number and length of curvatures, their degree of rotation and the size of the curvature angle. Early diagnosis of scoliosis in a clinical examination according to the Adams test depends on the correlation between the angle of trunk inclination (ATI) and the Cobb angle and the adopted diagnosis criterion. The aim of the study was to demonstrate the need to adopt different diagnostic criteria for ATI depending on the age and location of scoliosis. Moreover, the observed differences in the ATI/Cobb correlation became the basis for the proposal to introduce the concept of low, medium and high-rotated of curvature to the clinical description of scoliosis. Materials and methods The group consisted of 229 children who were first examined, aged 6 to 17 years, with an average age of -11.57 years (SD ± 3.26), with symptoms of idiopathic scoliosis. The correlation of the cr...
Comparison of Cobb Angle Measurement in Scoliosis by Residents and Spine Experts
Coluna/Columna, 2016
Objective: The adolescent idiopathic scoliosis (AIS) is a spine deformity that occurs in both the coronal plane and the sagittal plane of patients between 10 and 17 years. The Cobb method is the most widely used to determine the angular value of scoliosis and it is defined as the "gold standard". The goal is to verify the reproducibility of the measured angles between orthopedic residents and spinal pathologies specialists, comparing the variability of the angles measured by professionals with greater and lesser experience. Method: A total of 10 radiographs of patients diagnosed with AIS were assessed. Radiographs were handed over to 7 orthopedists specialized in spine and 14 orthopedic residents. The measurement of the angles for each of the examiners was described using means and standard deviations and intraclass correlations were calculated, as well as the measure of repeatability, and Bland-Altman plots were designed with the results of the measurements of each group ...
Application of two-parameter scoliometer values for predicting scoliotic Cobb angle
Biomedical engineering online, 2017
Adolescent idiopathic scoliosis, in which obvious curves are visible in radiographic images, is also seen in combination with lumps in the back. These lumps contribute to inclination, which can be measured by a scoliometer. To the authors' knowledge, there are no previous formulas combining thoracic and lumbar scoliometer values simultaneously to predict thoracic and lumbar Cobb angles, respectively. This study aimed to create more accurate two-parameter mathematical formulas for predicting thoracic and lumbar Cobb angles. Between Dec. 2012 and Jan. 2013, patients diagnosed with idiopathic scoliosis in an outpatient clinic were enrolled. The maximal trunk rotations at the thoracic and lumbar regions were recorded with a scoliometer. Right asymmetry hump was deemed positive (+), and left asymmetry hump was deemed negative (-). The Cobb angles were measured with a Picture Archiving and Communication System. Statistical analysis included Pearson's correlation coefficient, multi...