Interobserver and intraobserver reliability of Cobb angle measurement: endplate versus pedicle as bony landmarks for measurement: a statistical analysis

Psychometric properties of clinician-reported and performance-based outcomes cited in a scoping review on spinal manipulation and mobilization for pediatric populations with diverse medical conditions: a systematic review

INTRODUCTION

Risks and benefits of spinal manipulations and mobilization in pediatric populations are a concern to the public, policymakers, and international physiotherapy governing organizations. Clinical Outcome Assessments (COA) used in the literature on these topics are contentious. The aim of this systematic review was to establish the quality of clinician-reported and performance-based COAs identified by a scoping review on spinal manipulation and mobilization for pediatric populations across diverse medical conditions.

METHOD AND ANALYSIS

Electronic databases, clinicaltrials.gov and Ebsco Open Dissertations were searched up to 21 October 2022. Qualitative synthesis was performed using Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines to select studies, perform data extraction, and assess risk of bias. Data synthesis used Grading of Recommendations, Assessment, Development and Evaluations (GRADE) to determine the certainty of the evidence and overall rating: sufficient (+), insufficient (-), inconsistent (±), or indeterminate (?).

RESULTS

Four of 17 identified COAs (77 studies, 9653 participants) with supporting psychometric research were classified as:Performance-based outcome measures: AIMS - Alberta Infant Motor Scale (n = 51); or:Clinician-reported outcome measures: LATCH - Latch, Audible swallowing, Type of nipple, Comfort, Hold (n = 10),Cobb Angle (n = 15),Postural Assessment (n = 1).AIMS had an overall sufficient (+) rating with high certainty evidence, and LATCH had an overall sufficient (+) rating with moderate certainty of evidence. For the Cobb Angle and Postural Assessment, the overall rating was indeterminate (?) with low or very low certainty of evidence, respectively.

CONCLUSION

The AIMS and LATCH had sufficient evidence to evaluate the efficacy of spinal manipulation and mobilization for certain pediatric medical conditions. Further validation studies are needed for other COAs.

EPIDEMIOLOGICAL PROFILE AND OUTCOMES IN POSTOPERATIVE NEUROMUSCULAR ESCOLIOSIS

ABSTRACT Objective To outline the epidemiological profile and identify the hospital outcomes of patients submitted to neuromuscular scoliosis correction surgery. Methods This was a descriptive study that included 50 patients hospitalized following surgery for neuromuscular scoliosis in a tertiary-level hospital in São Paulo from January 2017 to July 2017. The variables were collected retrospectively from the patients’ medical records: age, sex, main diagnosis, length of hospital stay, duration of surgery, hospital complications, and mobility. Results Surgeries were performed in boys and girls in similar proportions, adolescents, many with cerebral palsy (42%), with mean hospital stay of 10.8 days. Fifty-two percent presented some complication, such as constipation. Infection of the surgical site was present in 12% of the sample. Forty-two percent had moderate to intense pain and only 2% did not achieve the proposed mobility goals. Conclusion We observed that the epidemiological profile presented data consistent with the scarce literature available, while the definitions of complications, incidence, and hospital outcomes available in the literature were varied quite a bit from the findings in this study. Level of evidence III; Retrospective study.

Oxford Cobbometer Versus Computer Assisted-Software for Measurement of Cobb Angle in Adolescent Idiopathic Scoliosis

OBJECTIVE

The objective was to compare Cobb angle measurements performed using an Oxford Cobbmeter and digital computer software (Surgimap) in a series of 83 adolescent idiopathic scoliosis (AIS) patients.

METHODS

Two independent observers measured the Cobb angles for 123 curves on 83 consecutive long radiographs of patients with AIS using both Oxford Cobbmeter and digital computer software (Surgimap). The measurements were repeated a week. Curves were classified according to the severity into mild, moderate, and severe. The results were statistically analyzed for intraobserver and interobserver reliability.

RESULTS

The mean Cobb angle was 48.12° ± 19.75° (range, 10.54°-110.76°). Globally the results of curve measurements were comparable between and within both observers using both methods, with small mean differences. According to intraclass correlation coefficient, there was high inter- and intraobserver high agreement for both methods. All readings were > 0.9. There was a good interobserver (κ = 0.745, 0.693) and a very good interobserver agreement (κ = 0.810, 0.804) for both methods for curve classification. However, poor agreement was observed as regards to the measurement time, being less with Oxford Cobbometer.

CONCLUSION

The results of this study indicate that the Surgimap digital computer software measurement is an equivalent measuring tool to the Oxford Cobbmeter in Cobb angle measurement. Both have high intra and interobserver agreement for measurement and for curve classification, with small measurement differences. Oxford Cobbmeter is advantageous in being quicker, and therefore it is the method of choice for manual measurement, where PACS (patient archiving and communication system) or digital system is not available.

Importância da experiência clínica para a mensuração da curva escoliótica de crianças pela técnica de Cobb

RESUMO A escoliose é definida como uma deformidade com desvio lateral da coluna no plano coronal, torsão da coluna e do tronco e distúrbio no perfil sagital. Essa alteração postural é avaliada por meio de radiografia de incidência anteroposterior, utilizando-se o método de Cobb. O objetivo do estudo é verificar a influência da experiência do avaliador sobre a confiabilidade intraexaminador e interexaminador do ângulo Cobb em curvaturas escolióticas de crianças. Foram incluídas na pesquisa 39 crianças portadoras de escoliose idiopática, com idade entre 7 e 18 anos. Os exames foram avaliados por dois fisioterapeutas, um quiropraxista e um estudante de fisioterapia - cada um avaliando duas vezes cada exame. A segunda avaliação ocorreu após sete dias, para confiabilidade intraexaminador. Ademais, as primeiras avaliações forneceram dados para confiabilidade interexaminador. A análise estatística foi realizada com coeficiente de correlação intraclasse (CCI), análise de Bland e Altman e análise descritiva do desvio absoluto médio, erro-padrão de medição e mínima mudança detectável. Observou-se boa confiabilidade (CCI>0,5) para as análises intraexaminadores entre os profissionais, e confiabilidade fraca (CCI=0,4) para o avaliador inexperiente. A confiabilidade interexaminador dos profissionais foi boa (CCI=0,6), e com a presença do avaliador inexperiente foi fraca (CCI=0,3). As avaliações entre os profissionais apresentaram menor variabilidade das medidas e valores de desvio-padrão quando comparadas com as do avaliador inexperiente. A mensuração dos ângulos da escoliose por meio do método de Cobb realizada por profissionais experientes apresentou melhores índices de concordância e de confiabilidade intra e interexaminadores e menor desvio-padrão e variabilidade entre as medidas.

The Duration of the correction loss after removing cheneau brace in patients with adolescent idiopathic scoliosis

OBJECTIVE

The aim of the study was to evaluate the loss of truncal rotation over 54 hours after removing Chêneau brace.

METHODS

The studied groups consisted of 39 girls aged 10-18 years old, diagnosed with adolescent idiopathic scoliosis (AIS) and treated with Chêneau brace (CAST) and 20 AIS girls aged 10-18 years old, not treated with bracing. Posterior-anterior radiographs were obtained from the clinical assessment of all subjects and were subsequently used to determine Cobb angles. The measurements of the angle of trunk rotation (ATR) were taken with the Scoliometer® and back-contour device during Adams forward bending test by the two evaluators. The changes in ATRs during 54 hours of observation were performed after the brace had been taken off (0, 2, 24, 30, 48 and 54 hours after debracing). This was described using VATR variable, defined as the change in the absolute Scoliometer® readings in the time intervals against the time interval Δt between the measurements. During back-contour assessment the differential factor (kra) has been used for the digital analysis. The changes in kra over 54 hours of observation were expressed as Vkra factor, defined as the difference in the absolute value of the amplitude differential factor (kra) in the time intervals against the time interval Δt between the measurements.

RESULTS

The highest changes were observed in the thoracic as well as in lumbar spine in patients with Cobb angle ≥30°, axial rotation of the apical vertebrae within 5-15°, Risser sign 0-2. The biggest change in the trunk rotation after Chêneau brace had been taken off was noted within the first two hours of observation.

CONCLUSION

The patients should be advised to take the brace off for a minimum of two hours before the scheduled x-ray, to allow full relaxation of the trunk in order to obtain reliable radiological images of the deformation.

LEVEL OF EVIDENCE

Level III Therapeutic study.

ADOLESCENT IDIOPATHIC SCOLIOSIS AND SIMILAR CONDITIONS: NEW TOOL TO MEASURE THE CORONAL PLANE

ABSTRACT Objective: To create a method to measure the overall coronal plane of the spine, called the sacral clavicular angle (SCA). Methods: A line is drawn at the base of the sacrum; a second central line is drawn perpendicular to the first one in the proximal extension of the spine. A third line is drawn passing through the intersections of the superior points of the clavicles with the two second ribs, forming two angles, the greater of which is measured. Therefore, the degrees exceeding 90° are the SCA values. This tool was tested retrospectively in a study of 46 patients with idiopathic scoliosis who underwent short, apical, single or multiple fixations. Third generation instrumentation was used and the SCA was evaluated in the pre- and postoperative periods, which were compared with another group of 46 patients treated with the traditional technique. Results: Patients submitted to the traditional fixation method presented a median SCA of 3° in the preoperative period, and in the postoperative period, the SCA remained in 3°. Therefore, there was a 0% reduction. Patients submitted to short, apical, single or multiple fixation method presented a median preoperative SCA of 6°, and a postoperative median SCA of 1°, a reduction of approximately 83%. Conclusions: The group treated with short, apical, single or multiple instrumentation presented a reduction in the SCA of approximately 83% in the postoperative period compared to the preoperative period. The difference between preoperative and postoperative values was considered statistically significant. Level of Evidence II; Retrospective study.

A comprehensive review of the diagnosis and management of congenital scoliosis

PURPOSE

To provide the reader with a comprehensive but concise understanding of congenital scoliosis METHODS: We have undertaken to summarize available literature on the pathophysiology, epidemiology, and management of congenital scoliosis.

RESULTS

Congenital scoliosis represents 10% of pediatric spine deformity and is a developmental error in segmentation, formation, or a combination of both leading to curvature of the spine. Treatment options are complicated by balancing growth potential with curve severity. Often associated abnormalities of cardiac, genitourinary, or intraspinal systems are concurrent and should be evaluated as part of the diagnostic work-up. Management balances the risk of progression, growth potential, lung development/function, and associated risks. Surgical treatment options involve growth-permitting systems or fusions.

CONCLUSION

Congenital scoliosis is a complex spinal problem associated with many other anomalous findings. Treatment options are diverse but enable optimization of management and care of these children.

Cobb angle measurements on digital radiographs using Bunnell scoliometer: Validation of the method

BACKGROUND

Electronic rulers on computer screen are used to measure the Cobb angle (CA) instead of traditional methods with rulers, protractors and pens. The variety of software used to assess radiographs might make the CA measurements cumbersome in everyday clinical practice.

OBJECTIVE

The aim of the study was to verify the method of CA measurements on digital radiographs using Bunnell scoliometer (BS).

METHODS

Eighty patients with idiopathic scoliosis were enrolled into the study. CA of each curve was measured by use of Centricity software and BS. CA on 30 randomly chosen patients were measured 3 times by one researcher using only scoliometer. Three researchers measured CA on the same 30 radiographs using BS.

RESULTS

The mean CA of 224 curves measured by Centricity and BS were 29° ± 12.2° and 28° ± 11.7°, respectively. The ICC for agreement for 2 methods was 0.96 with SEM of 1.7°. Excellent intra- and interobserver reliability of CA measurements with scoliometer was noted: ICC of 0.96 with SEM of 1.4° and ICC of 0.93 with SEM of 1.9°, respectively.

CONCLUSIONS

The study revealed excellent reliability of CA measurements on digital radiographs using the BS. The proposed method of using the Bunnell scoliometer for CA measurements may be clinically useful.

Spine and Thoracic Height Measurements Have Excellent Interrater and Intrarater Reliability in Patients With Early Onset Scoliosis

STUDY DESIGN

Reproducibility of measurements.

OBJECTIVE

This study investigates the reliability and standard error of measurement of spine and thoracic height radiographic measurements in patients with early onset scoliosis (EOS).

SUMMARY OF BACKGROUND DATA

Spine and thoracic height radiographic measurements are often used as a surrogate for pulmonary development in patients with EOS. There is limited literature validating the reliability of spine and thoracic height measurements in the EOS population.

METHODS

Using pilot data, we determined measuring 49 unique radiographs would provide 80% power to obtain a 95% confidence interval (CI) width of 0.05 for the interclass correlation coefficients (ICCs). A random sampling strategy, stratified by underlying diagnosis from the Classification of Early Onset Scoliosis (C-EOS), was used to distribute the diagnoses in the study sample. Two attending pediatric spine surgeons, two pediatric orthopedic fellows, and two research assistants measured coronal spine (T1-S1) and thoracic (T1-T12) height on digital radiographs using imaging software (Surgimap; Nemaris, Inc, New York) on two separate occasions at least 3 weeks apart. Order of images was randomized for the second iteration. Linear mixed model regression analyses were used to estimate interrater and intrarater reliability.

RESULTS

The study sample included subjects (N = 48) with idiopathic (N = 17, 35%), congenital (N = 16, 33%, 1 patient excluded), neuromuscular (N = 11, 23%), and syndromic (N = 4, 8%) scoliosis. Overall interrater reliability estimates for spine height (ICC: 0.894, 95% CI: 0.847-0.932) and thoracic height (ICC: 0.890, 95% CI: 0.844-0.929) were excellent. Intrarater reliability estimates for spine height (ICC: 0.906, 95% CI: 0.830-0.943) and thoracic height (ICC: 0.898, 95% CI: 0.817-0.938) were also excellent.

CONCLUSION

There is excellent interrater and intrarater reliability for radiographic measurements of spine and thoracic height in the EOS population at our institution.

LEVEL OF EVIDENCE

2.

Reliability analysis of Cobb measurement in degenerative lumbar scoliosis using endplate versus pedicle as bony landmarks

OBJECTIVES

Degenerative changes of endplates in older patients and tilting of vertebral body in lumbosacral lordosis could make an accurate identification of endplates for the Cobb measurement difficult. Pedicles have been proposed as alternative landmarks because they are usually better visualized, and offer similar clinical validity to the endplates. The objective of this study was to investigate the reliability of the pedicle method of Cobb measurement in degenerative lumbar scoliosis and compare it with the traditional endplate method.

METHODS

Two hundred and eighty-four radiographs of degenerative lumbar scoliosis were evaluated. The radiographs were classified into groups based on the patient's age (< 60 years, 60 to 80 years, and > 80 years), level of lower end vertebra (LEV) (LEV at L5, and LEV at or above L4), and curve severity (< 20°, 20° to 40°, and > 40°). Three observers independently measured the radiographs using the endplate and pedicle methods twice with an interval of 1 week. The intra- and interobserver reliabilities were calculated using intraclass correlation coefficients (ICC).

RESULTS

The intra- and interobserver ICC values were better for all observers in the > 80 years age group using the pedicle method. The intraobserver ICC values of pedicle method were also better in the LEV at L5 group, and the interobserver ICC values showed a slightly better consistency with the pedicle method. For patients with > 40° curves, the intraobserver ICC values for all observers as well as interobserver ICC values were better using the endplate method.

CONCLUSION

The reliabilities of the endplate and pedicle methods for degenerative lumbar scoliosis were both excellent. The pedicle method might be better in older patients (> 80 years) and those with LEV at L5; while the endplate method could have some strength in severe cases (> 40°).

Surgical treatment of Lenke 5 adolescent idiopathic scoliosis: Comparison of anterior vs posterior approach

AIM

To compare the posterior vs anterior approaches for fusion of Lenke 5 adolescent idiopathic scoliosis curves, matched for curve magnitude and for the distal level of fixation (dLOF) standardized to the third lumbar vertebrae (L3).

METHODS

A prospectively collected multicenter database was used for this retrospective comparative study. Our dependent variables included sagittal and coronal radiographic measurements, number of fused vertebrae, estimated blood loss, length of hospitalization and SRS total and individual domain scores at the two-year follow-up. Subject demographics were similar for all group comparisons. Independent t-test was used to compare groups for all analyses at P < 0.01.

RESULTS

For all matched cases of Lenke 5 curves, a selective approach was used only 50% of the time in cases undergoing a posterior fusion. When comparing a posterior selective approach to an anterior selective approach, surgeons utilizing a posterior approach fused significantly more levels than surgeons using an anterior approach with no other significant differences in radiographic or SRS outcomes (Ant = 4.8 ± 1.0 levels vs post = 6.1 ± 1.0 levels, P < 0.0001). When the dLOF was standardized to L3, the anterior approached provided significantly greater lumbar Cobb percent correction than the posterior approach (Ant = 69.1% ± 12.6% vs post = 54.6% ± 16.4%, P = 0.004), with no other significant radiographic or SRS score differences between approaches.

CONCLUSION

Surgeons treating Lenke 5c curves with a posterior instrumentation and fusion vs an anterior approach include more motion segments, even with a selective fusion. When controlled for the distal level of fixation, the anterior approach provides greater correction of the thoracolumbar curve.

COMPARISON OF COBB ANGLE MEASUREMENT IN SCOLIOSIS BY RESIDENTS AND SPINE EXPERTS

ABSTRACT 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 of examiners, according to experience, to assess the agreement/reproducibility of Cobb angle measurements. Results: Each examiner obtained a resulting average of 10 cases summation. In order to assess trends in variability of the measurements of the angles of each group graphs were plotted based on the arithmetic mean of each of the 10 cases by the total number of participants in the group versus the standard deviation in each case. Conclusion: There was a poor correlation (ICC=0.4) in the measurement of Cobb in both groups, demonstrating difficulties in the method, which cannot be overcome by the expertise.

Reliability and Validity Study of Clinical Ultrasound Imaging on Lateral Curvature of Adolescent Idiopathic Scoliosis

Background

Non-ionizing radiation imaging assessment has been advocated for the patients with adolescent idiopathic scoliosis (AIS). As one of the radiation-free methods, ultrasound imaging has gained growing attention in scoliosis assessment over the past decade. The center of laminae (COL) method has been proposed to measure the spinal curvature in the coronal plane of ultrasound image. However, the reliability and validity of this ultrasound method have not been validated in the clinical setting.

Objectives

To evaluate the reliability and validity of clinical ultrasound imaging on lateral curvature measurements of AIS with their corresponding magnetic resonance imaging (MRI) measurements.

Methods

Thirty curves (ranged 10.2°–68.2°) from sixteen patients with AIS were eligible for this study. The ultrasound scan was performed using a 3-D ultrasound unit within the same morning of MRI examination. Two researchers were involved in data collection of these two examinations. The COL method was used to measure the coronal curvature in ultrasound image, compared with the Cobb method in MRI. The intra- and inter-rater reliability of the COL method was evaluated by intra-class correlation coefficient (ICC). The validity of this method was analyzed by paired Student’s t-test, Bland–Altman statistics and Pearson correlation coefficient. The level of significance was set as 0.05.

Results

The COL method showed high intra- and inter-rater reliabilities (both with ICC (2, K) >0.9, p<0.05) to measure the coronal curvature. Compared with Cobb method, COL method showed no significant difference (p<0.05) when measuring coronal curvature. Furthermore, Bland-Altman method demonstrated an agreement between these two methods, and Pearson’s correlation coefficient (r) was high (r>0.9, p<0.05).

Conclusion

The ultrasound imaging could provide a reliable and valid measurement of spinal curvature in the coronal plane using the COL method. Further research is needed to validate the proposed ultrasound measurement in larger clinical trial and to optimize the ultrasound scanning and measuring procedure.

Intra-familial tests of association between familial idiopathic scoliosis and linked regions on 9q31.3-q34.3 and 16p12.3-q22.2

OBJECTIVE

Custom genotyping of markers in families with familial idiopathic scoliosis were used to fine-map candidate regions on chromosomes 9 and 16 in order to identify candidate genes that contribute to this disorder and prioritize them for next-generation sequence analysis.

METHODS

Candidate regions on 9q and 16p-16q, previously identified as linked to familial idiopathic scoliosis in a study of 202 families, were genotyped with a high-density map of single nucleotide polymorphisms. Tests of linkage for fine-mapping and intra-familial tests of association, including tiled regression, were performed on scoliosis as both a qualitative and quantitative trait.

RESULTS AND CONCLUSIONS

Nominally significant linkage results were found for markers in both candidate regions. Results from intra-familial tests of association and tiled regression corroborated the linkage findings and identified possible candidate genes suitable for follow-up with next-generation sequencing in these same families. Candidate genes that met our prioritization criteria included FAM129B and CERCAM on chromosome 9 and SYT1, GNAO1, and CDH3 on chromosome 16.

A comparative analysis of 4 curvature measurement methods in early-onset scoliosis

STUDY DESIGN

Observational study with 3 examiners.

OBJECTIVE

The aim of this study was to enhance the reproducibility and reliability of coronal curvature measurements in early-onset scoliosis.

SUMMARY OF BACKGROUND DATA

Previous reports show high variability of the Cobb method, especially on the measurement of the immature spine.

METHODS

A total of 115 whole-spine posteroanterior radiographs were collected to compare the reliability of the Cobb, lateral tangent, pedicle, and centroid methods in early-onset scoliosis. Radiographs were measured twice by each of the 3 examiners using the 4 measurement methods. Statistical analysis was performed to determine the inter- and intraobserver reliability.

RESULTS

In this study, total inter- and intraobserver inter- and intraclass correlation coefficients (ICCs) in 115 radiographs were excellent in all methods (ICCs >0.961). However, mean absolute differences (MADs) in the lateral tangent method were less than 3.78°, which was higher than other methods (MADs <2.95°). In analysis of different severity groups (<15°, 15°-30°, and >30°), total inter- and intraobserver ICCs gradually increased with increasing the severity of the deformity, whereas MADs of each severity group were similar despite their increased measurement scale. Particularly, interobserver ICCs and MADs of lateral tangent method were more than 0.474 and less than 3.76° with poor reliability, which showed high variability in the less deformed spine group (<15°). However, intraobserver ICCs and MADs of pedicle method were more than 0.853 and less than 2.61°, interobserver ICCs and MADs were more than 0.729 and less than 2.86° with excellent reliability, which showed constantly high reliability regardless of coronal curvature severity.

CONCLUSION

In this study, the pedicle method showed constantly higher ICCs and lower MAD values in the early-onset scoliosis regardless of severity. However, the other 3 methods showed lower ICCs and higher MAD values, which showed lowest reliability in the lateral tangent method. For improved treatment of early-onset scoliosis, we recommend the pedicle method for measuring curvature regardless of severity.

Using ultrasound imaging to identify landmarks in vertebra models to assess spinal deformity

Scoliosis is a type of spinal deformity that commonly develops in adolescents. Cobb angle, using the most tilted vertebrae, is the gold standard to assess scoliosis on radiographs. However, regularly taking radiographs introduces harmful ionizing radiation to patients, thus non-ionizing radiation methods have been explored for many years. Ultrasound has been proposed as one of the non-ionizing radiation methods to measure the deformity. This research was divided into two studies: 1) to investigate the reliability and repeatability of a new proposed method to measure Cobb angle; 2) to determine if landmarks can be identified from ultrasound images to measure curvature of spine. Based on the two studies, the feasibility of using ultrasound images to assess spinal deformity will be determined. Thirty-nine radiographs were used in the first study. The new method agreed well with the traditional Cobb method with intraclass correlation coefficient (ICC) value greater than 0.7 in different severity groups, and the average angle difference was 1.6° ± 3.1°. The second study showed laminae and transverse processes could be recognized from ultrasound images. The difference of the width of the laminae between the phantom and the ultrasound image was 0.3 mm. Therefore, it is feasible to use the proposed method and the laminae from the ultrasound images to assess the severity of scoliosis.

Centroid method: reliable method to determine the coronal curvature of scoliosis: a case control study comparing with the Cobb method

STUDY DESIGN

Observational study with three examiners.

OBJECTIVE

To compare the reliability of the Cobb and centroid methods.

SUMMARY OF BACKGROUND DATA

The Cobb method is considered to be the gold standard in scoliosis measurement despite its low reliability. In adolescent idiopathic scoliosis (AIS) patients, the centroid method can be a good method for measuring scoliosis.

METHODS

Sixty whole spine postero-anterior radiographs were collected to compare the reliability of the Cobb and centroid methods in AIS patients. Sixty radiographs were measured twice by each of the three examiners using the two measurement methods. The data were analyzed statistically to determine the inter- and intraobserver reliability.

RESULT

In comparisons of inter- and intraobserver reliability of all 60 radiographs, the inter- and intraclass coefficients (ICCs) were higher in the centroid (>0.969) than in the Cobb method (>0.832), although both were in the excellent range. The mean absolute difference (MAD) values were higher in the Cobb method (<7.15° vs. <3.75°), and >5° in five comparisons. Regarding measures of mismatched radiograms, the inter- and intraobserver MAD values were higher in the Cobb method (<9.81° vs. <3.82°), and >5° in six comparisons. And, the ICCs were higher in the centroid method (>0.972) than the Cobb method (>0.758). In immature radiograms, the ICCs were higher in the centroid (>0.973) than in the Cobb method (>0.764), even though it was in the excellent range. And, the inter- and intraobserver MAD values were higher in the Cobb method (<8.49° vs. <3.99°), and >5° in seven comparisons.

CONCLUSION

The centroid method is more reliable for measuring scoliosis in AIS than the Cobb method, and it can substitute the Cobb method, which showed high variability.

Mensuração da curva escoliótica pela técnica de cobb intraobservadores e interobservadores e sua importância clínica

OBJETIVO: Analisar a mensuração manual do ângulo de Cobb entre profissionais com diferentes experiências da área de Ortopedia e Traumatologia e Cirurgia da Coluna Vertebral, para observar se existem diferenças na avaliação das radiografias de pacientes portadores de escoliose idiopática intra e interobservadores, a ponto de influenciar no tratamento e seguimento desses pacientes. MÉTODOS: Foram utilizadas para este estudo 22 radiografias simples da coluna toracolombar, póstero-anterior, de pacientes portadores de escoliose idiopática, em acompanhamento regular no ambulatório do Grupo da Coluna do Hospital São Paulo. Os exames foram avaliados por quatro diferentes categorias de profissionais ortopedistas e cirurgiões da coluna vertebral e realizada a mensuração das curvas escolióticas através do método de Cobb. As vértebras terminais das curvas não foram previamente marcadas. Somente foram mensuradas as curvas principais (consideradas as de maior valor angular) de cada radiografia. A reprodutibilidade das mensurações feitas pelos diferentes Observadores (inter-observadores) e entre as duas mensurações de cada Observador (intraobservador) foi analisada pelo Coeficiente de Correlação Intraclasse (CCI). RESULTADOS: Foram observadas, quanto às medidas dos ângulos, concordâncias excelentes entre as avaliações intraobservadores, e observadas concordâncias excelentes entre as avaliações interobservadores, uma vez que o CCI em todas as situações manteve-se maior que 0,75, o que representa excelente reprodutibilidade. CONCLUSÃO: Concluímos que houve concordância excelente (CCI > 0,75) na avaliação dos ângulos nas mensurações das curvas escolióticas intra e interobservadores. Ao mesmo tempo, as mensurações apresentaram variação de até 13,58º intraobservadores, e de até 12,72º interobservadores.