Radiographic versus ultrasound evaluation of the Risser Grade in adolescent idiopathic scoliosis: a prospective study of 46 patients

A Comparative Study on the Consistency of Ultrasound and X-Ray in Assessing Risser Sign

OBJECTIVES

Adolescent idiopathic scoliosis (AIS) is a 3-dimensional spinal deformity involving lateral curvature, sagittal plane imbalance, and vertebral rotation. In China, AIS affects over 3 million individuals, with 300,000 new cases annually. AIS impacts physical and psychological well-being, necessitating tailored treatment plans based on growth risk factors. This study evaluates the consistency of ultrasound and X-ray assessments of the Risser sign in AIS patients and explores correlations between iliac crest distance and pelvic rotation degree.

METHODS

This prospective study enrolled 80 patients diagnosed with AIS from June to September 2023 at Changzhou Sports Hospital. Eligible participants were aged 10-18 with a Cobb angle >10°. Ultrasonographic examinations were conducted by 3 experienced physicians using the VINNO V10 portable ultrasound system. The primary outcome was the Risser stage determined by X-ray and ultrasound, with secondary outcomes including thoracic and thoracic-lumbar segment rotation angles. Statistical analyses included kappa statistics, correlation analyses, and multiple regression.

RESULTS

Among the 77 valid cases, 154 iliac wings were evaluated, with a high concordance rate of 77% between ultrasound and X-ray assessments. kappa values for left and right iliac crests were 0.723 and 0.808, respectively. Grouping Risser grades (0-1, 2-3, and 4-5) into 3 categories yielded kappa values of 0.93, 0.96, and 0.93, indicating high consistency. Significant correlations were found between iliac crest distances and rotation angles (left iliac crest distance and left thoracic rotation angle, r = 0.56, P < .001; right iliac crest distance and right thoracic-lumbar rotation angle, r = 0.69, P < .001; right iliac crest distance and right thoracic rotation angle, r = 0.39, P < .01).

CONCLUSIONS

Ultrasound is a reliable, radiation-free alternative to X-ray for assessing the Risser sign in AIS patients. Despite observed inconsistencies in intermediate Risser grades, ultrasound's ability to reduce radiation exposure and provide consistent results makes it a valuable tool in clinical practice. Further research is needed to optimize ultrasound techniques and explore its potential for early detection and intervention in scoliosis management.

Using B-mode ultrasound to evaluate Risser grading for the determination of skeletal maturity in adolescents

INTRODUCTION

Rapid adolescent growth is associated with an increased risk of disease and disease progression. This study assesses the reliability and validity of non-ionising B-mode ultrasound for the assessment of skeletal maturity (Risser Grade) and offers procedural guidelines for its use.

METHODS

Twenty-three female adolescents with primary-right-thoracic scoliosis (age: 13.8 (1.6) years) and twenty age-matched female control participants without scoliosis (age: 13.1 (1.8) years) were recruited. Skeletal maturity was determined from (i) a series of nine B-mode ultrasound images collected at sites equally spaced between the anterior and posterior superior iliac spines of the pelvis and (ii) clinical spine radiographs obtained as part of standard scoliosis care. Inter-rater reliability was assessed between a novice researcher and an experienced medical doctor. Concurrent-validity was assessed by comparing the location and degree of apophysis growth and fusion obtained via ultrasound with that obtained using radiograph Risser grading for scoliosis participants only.

RESULTS

The inter-rater reliability of ultrasound Risser grading was strong [ICC(2,1): 0.99, p < 0.001]. High concurrent-validity was determined, with no difference in Risser grading identified between the radiograph and ultrasound grading methods (Wilcoxon signed-rank: Z = -1.93, p = 0.053).

CONCLUSION

Ultrasound provides a reliable non-ionising alternative to the gold standard of Risser grading from radiographs to determine and monitor skeletal maturity. This study provides a detailed methodology for using ultrasound to assess skeletal maturity.

IMPLICATIONS FOR PRACTICE

Rapid adolescent growth is associated with an increased risk of disease and disease progression. Therefore, accurately determining and monitoring skeletal maturity in these adolescents is crucial. This study assesses the reliability and validity of non-ionising B-mode ultrasound for the assessment of skeletal maturity and offers procedural guidelines for its use.

Machine learning and regression analysis for age estimation from the iliac crest based on computed tomographic explorations in an Indian population

Age estimation constitutes an integral parameter of identification. In children, sub-adults, and young adults, accurate age estimation is vital on various aspects of civil, criminal, and immigration law. The iliac crest presents as a suitable age marker within these age cohorts, and the modified Risser method constitutes a relatively novel and unexplored method for iliac crest age estimation. The present study attempted to ascertain the applicability of this modified method for age estimation in the Indian population, an aspect previously unexplored, through computed tomographic examination of the iliac crest. Computed tomography scans of consenting individuals undergoing routine examinations of the pelvis/ abdomen for various clinically indicated reasons were collected and scored using the modified Risser stages. Computed tomographic examinations of the iliac crest indicate that the recalibrated method accurately depicts the temporal progression of ossification and fusion changes. Different regression and machine learning models were subsequently derived and/or trained to evaluate the accuracy and precision associated with the method. Amongst the ten regression models derived herein, compound regression exhibited the lowest inaccuracy (4.78 years) and root mean squared error values (5.46 years). Machine learning yielded further reduced error rates, with decision tree regression achieving inaccuracy and root mean squared error values of 1.88 years and 2.28 years, respectively. A comparative evaluation of error computations obtained from regression analysis and machine learning illustrates the statistical superiority of machine learning for forensic age estimation. Error computations obtained with machine learning suggest that the modified Risser method is capable of permitting reliable age estimation within criminal and civil proceedings.

Ultrasound Imaging-Based Methods for Assessing Biological Maturity during Adolescence and Possible Application in Youth Sport: A Scoping Review

Bone maturity is an indicator for estimating the biological maturity of an individual. During adolescence, individuals show heterogeneous growth rates, and thus, differences in biological maturity should be considered in talent identification and development. Radiography of the left hand and wrist is considered the gold standard of biological maturity estimation. The use of ultrasound imaging (US) may be advantageous; however, its validity and reliability are under discussion. The aims of this scoping review are (1) to summarize the different methods for estimating biological maturity by US imaging in adolescents, (2) to obtain an overview of the level of validity and reliability of the methods, and (3) to point out the practicability and usefulness of ultrasound imaging in the field of youth sports. The search included articles published up to November 2022. The inclusion criteria stipulated that participants had to fall within the age range of 8 to 23 years and be free of bone disease and fractures in the region of interest. Nine body regions were investigated, while the hand and wrist were most commonly analyzed. US assessment methods were usually based on the estimation of a bone maturity stage, rather than a decimal bone age. Furthermore, 70% of the assessments were evaluated as applicable, 10% expressed restraint about implementation, and 20% were evaluated as not applicable. When tested, inter- and intra-rater reliability was high to excellent. Despite the absence of ionization, low costs, fast assessment, and accessibility, none of the US assessments could be referred to as a gold standard. If further development succeeds, its application has the potential to incorporate biological age into selection processes. This would allow for more equal opportunities in talent selection and thus make talent development fairer and more efficient.

Earlier appearance of Risser sign on ultrasound versus radiograph in adolescent idiopathic scoliosis

Objective

The usefulness of ultrasound in the detailed assessment of the Risser sign is still unclear. The purpose of this study was to analyze the usefulness of ultrasound for determining the Risser sign compared with that determined by conventional radiography by each Risser grade.

Materials and Methods

Eighty-eight iliac crests from 44 adolescent patients who visited the scoliosis clinic with Risser grades 0-4 were evaluated. The ultrasound probe was placed vertically on the iliac crest and the point where iliac apophysis ossification ended was marked. The length of ossification relative to the length of the iliac crest was calculated.

Results

Agreement between radiographic and ultrasound images were found in 58/86 iliac crests (67%). Kappa value was 0.565. Agreement between the two methods with regard to Risser grade was 53% for grade 0, 43% for grade 1, 47% for grade 2, 88% for grade 3, and 90% for grade 4. With additional analysis by integrating grades into two groups, the agreement rate was 47.7% and the Kappa value was 0.288 in the grade 0-2 group, and 88% and 0.703 in grades 3-4 group, respectively. In cases of disagreements, 93% of the iliac crests were judged as having higher Risser grades by ultrasound than by radiograph.

Conclusion

Risser sign evaluation by ultrasound demonstrated a higher agreement rate in grades 3 and 4, whereas less agreement was found in grades 0-2. In the majority of cases with disagreement, ultrasound showed a higher grade than radiography, suggesting that ossification can be detected earlier with ultrasound than with radiography.

Imaging in the Diagnosis and Monitoring of Children with Idiopathic Scoliosis

The paper reviews the current imaging methods in the diagnosis and monitoring of patients with adolescent idiopathic scoliosis. Radiography is generally used in the initial diagnosis of the condition. Postero-anterior erect full spine radiograph is generally prescribed, and is supplemented by lateral full spine radiograph when indicated. To reduce the radiation hazard, only the area of interest should be exposed, and follow-up radiographs should be taken with as few projections as possible. When available, EOS® stereoradiography should be used. The radiation of the microdose protocol is 45 times less than that of the conventional radiography. Surface topography offers another approach to monitoring changes of curvatures in AIS patients. Recently, 3D ultrasound has been found to be able to measure the Cobb angle accurately. Yet, it is still in the early developmental stages. The inherent intrinsic and external limitations of the imaging system need to be resolved before it can be widely used clinically. For AIS patients with atypical presentation, computed tomography (CT) and/or magnetic resonance imaging (MRI) may be required to assess for any underlying pathology. As CT is associated with a high radiation dose, it is playing a diminishing role in the management of scoliosis, and is replaced by MRI, which is also used for pre-operative planning of scoliosis. The different imaging methods have their limitations. The EOS® stereoradiography is expensive and is not commonly available. The surface topography does not enable measurement of Cobb angle, particularly when the patient is in-brace. The 3D ultrasound scanning has inherent intrinsic technical limitation and cannot be used in all subjects. Radiography, however, enables diagnosis and monitoring of the adolescent idiopathic scoliosis (AIS). It is thus the gold standard in the evaluation and management of scoliosis curves.

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.

Evaluation of accuracy of plain radiography in determining the Risser stage and identification of common sources of errors

Background

Risser’s sign is an established radiological marker for predicting growth potential in adolescent idiopathic scoliosis, but the accuracy of Risser’s staging has been debated. This research was designed to evaluate the accuracy of Risser’s staging and to identify causes of errors in Risser’s staging.

Materials and methods

Plain radiographs of 89 adolescent idiopathic scoliosis patients were evaluated for Risser’s stage using both the Original and French methods. A three-dimensional computed tomography (3D-CT) was used to evaluate the accuracy of the plain radiographs. Inter- and intra-observer reliability of both methods was assessed on radiographs and 3D-CT images using weighted kappa statistics. The concordance rate for Risser’s staging between plain radiographs and 3D-CT images were calculated. The various sources of staging differences between the two imaging methods were noted, grouped, and analyzed to identify common error patterns.

Results

Intra- and inter-observer staging reliabilities on plain radiography were 0.91 and 0.94, respectively, using the Original method and 0.91 and 0.92, respectively, using the French method. Intra- and inter-observer reliabilities on 3D-CT were 0.98 and 0.99, respectively, using the Original method and 0.97 and 0.99, respectively, using the French method. Mean concordance rates between plain radiography and 3D-CT were 59.76% and 67.42% using the Original and French methods, respectively. Common sources of error leading to misinterpretation of Risser’s staging were miscalculation of apophysis excursion, skip ossification, isolated non-linear ossification, micro-fusion, and pseudo-fusion.

Conclusions

Risser’s staging by plain radiography is reliable but not accurate. Variations in the iliac apophysis ossification and misinterpretation of apophysis fusion are the main sources of error.

Spine ultrasonography: interventions and diagnostics

SUMMARY Ultrasound-guided procedures are well established and utilized in the regional anesthesia and radiology practice. Conversely, there have been considerable difficulties in implementation of ultrasound in pain medicine. Ultrasonography has to compete with the more established modalities such as fluoroscopy and computed tomography; however, ultrasound has the advantage of radiation safety and point-of care imaging. It also allows direct visualization of tissue planes, blood vessels and nerves. Ultrasound-guided spine interventions are technically feasible and reasonably accurate when validated with conventional radiological modalities. Epidural, zygapophysial joint and caudal injection techniques have been published. The main pitfall of the ultrasound-guided spinal procedures lies in the inability to diagnose intravascular injections. Future technological improvements will help to solve this problem. Diagnostic spinal sonography may also contribute to the practice of medicine helping in the clinical workup of scoliosis and paraspinal pathology.

Ultrasonographic evaluation of the Risser sign. Is it a reliable and reproducible method?

STUDY DESIGN

A prospective study of ultrasonographic evaluation (UE) results of the Risser sign (RS) in adolescents.

OBJECTIVE

This study aims to assess the efficiency of UE of RS, compare it with radiographic evaluation, and investigate the intraexaminer and interexaminer reliability of UE.

SUMMARY OF BACKGROUND DATA

The use of ultrasound in orthopedic practice has a growing popularity. As a noninvasive radiological method, the evaluation of RS seems to be a promising alternative in patients suffering from scoliosis who require a long-term follow-up.

METHODS

This study consists of 142 patients (70 female and 72 male cases) aged between 10 and 17 years, with a mean age of 13.8 ± 1.7 years. Menarche experience, body mass index, and skinfold thickness of the patients were recorded. Forty-five patients were found to have scoliosis. All ultrasonographic and radiographic evaluations were made by 2 blinded orthopedists. X-ray was considered as the gold standard.

RESULTS

Percentage accuracy of UE was found to be 77.7% (κ = 0.698) for the first examiner and 64.30% (κ = 0.542) for the second examiner. Intraexaminer and interexaminer agreement were 0.971 and 0.924 for the UE, respectively. Moreover, interexaminer agreement for radiographic evaluation was 0.689. No significant difference was observed between the values of scoliosis and nonscoliosis patients. When the patients with a skinfold thickness of 16 mm or less and more than 16 mm were examined, the percentage accuracy of the UE was 80.43% (κ = 0.727) for the first group, whereas it was 72.91% (κ = 0.637) in the other group.

CONCLUSION

We found the intraexaminer and interexaminer agreement for the UE of RS to be reliable. In radiographic evaluation of RS, the intraexaminer and interexaminer agreement were lower. These findings were also consistent with data from the literature. In conclusion, UE of RS is a reliable method; however, the results may vary when x-ray is considered as the gold standard.

Efeitos da Reeducação Postural Global em escolares com escoliose

O objetivo deste estudo foi analisar o efeito do método da Reeducação Postural Global (RPG) em escolares com diagnóstico de escoliose torácica não estrutural (ETNE). Os escolares com indicativo de ETNE ao exame postural e teste de Adams negativo foram encaminhados ao exame radiográfico para comprovação diagnóstica. Foram selecionados 20 participantes (11 meninos e 9 meninas, com 10±3 anos), divididos randomicamente em dois grupos homogêneos: o que realizou o RPG (GRPG) durante 12 semanas com duração de 25 a 30 minutos cada sessão, de acordo com o que aguentou permanecer na postura; e o grupo controle (GC), sem intervenção. Após três meses, os dois grupos repetiram a avaliação postural e o exame radiográfico. Para avaliação das estatísticas, foi utilizada análise de variância (ANOVA) univariada, com medidas repetidas, seguida do Post Hoc de Tukey para identificar as possíveis diferenças intra e intergrupos. O valor de α foi de 0,05. O GRPG apresentou redução significativa no ângulo de Cobb na comparação intragrupo (Δ%=-35,100; p=0,009), mas o GC não (Δ%=9,520; p=0,789). Pode-se concluir que escolares submetidos ao método da RPG apresentaram melhora do quadro de escoliose torácica não estrutural.

[Imaging of non-traumatic spinal diseases in children]

Pain is also the main symptom of spinal diseases in children. The younger the child, the more frequently organic causes are to be found, whereas in adolescents functional dorsalgia and lumbalgia are ubiquitous. Apart from the neonatal period, where ultrasound is used as the primary method for investigation of closed spinal dysraphia, radiography is still considered to be the first choice examination, which nevertheless should only be carried out after a thorough anamnesis and clinical examination. For targeted follow-up and especially exclusion of neoplasms, MRI is the method of choice in most cases. Computed tomography (CT) plays an important role preoperatively and postoperatively in corrective spine surgery and together with scintigraphy in the diagnostics of spondylolysis and some tumors such as osteoid osteoma. Important is the care of children with hereditary spinal malformations, especially dysraphias where the entire CNS may be affected as with the common association of myelomeningocele and Chiari II malformation with hydrocephalus and hydromyalia.

Update on the management of idiopathic scoliosis

PURPOSE OF REVIEW

Idiopathic scoliosis is a lateral curvature of the spine greater than 10 degrees for which there is no known cause. This paper reviews the current literature on the appropriate evaluation and treatment of patients with idiopathic scoliosis.

RECENT FINDINGS

Improved technology and surgical techniques are allowing improved curve correction and improved quality of life for these patients. Specifically, the pedicle screw construct can provide excellent curve correction and stabilization for spinal deformities.

SUMMARY

Idiopathic scoliosis is a diagnosis of exclusion and the approach to a patient with scoliosis should aim toward ruling out other possible causes. In those patients with scoliosis necessitating treatment, bracing should be the first line of treatment and these patients should be followed up closely to track curve progression. Patients who fail conservative management may undergo spinal fusion with pedicle screw instrumentation. Vigilant monitoring and thorough evaluation of scoliosis patients can steer patients toward appropriate management in a judicious manner preventing the significant medical morbidity and deformity that scoliosis can insidiously inflict.