Reevaluation of the use of the Risser sign in idiopathic scoliosis

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.

Deep learning-based identification of spine growth potential on EOS radiographs

OBJECTIVES

To develop an automatic computer-based method that can help clinicians in assessing spine growth potential based on EOS radiographs.

METHODS

We developed a deep learning-based (DL) algorithm that can mimic the human judgment process to automatically determine spine growth potential and the Risser sign based on full-length spine EOS radiographs. A total of 3383 EOS cases were collected and used for the training and test of the algorithm. Subsequently, the completed DL algorithm underwent clinical validation on an additional 440 cases and was compared to the evaluations of four clinicians.

RESULTS

Regarding the Risser sign, the weighted kappa value of our DL algorithm was 0.933, while that of the four clinicians ranged from 0.909 to 0.930. In the assessment of spine growth potential, the kappa value of our DL algorithm was 0.944, while the kappa values of the four clinicians were 0.916, 0.934, 0.911, and 0.920, respectively. Furthermore, our DL algorithm obtained a slightly higher accuracy (0.973) and Youden index (0.952) compared to the best values achieved by the four clinicians. In addition, the speed of our DL algorithm was 15.2 ± 0.3 s/40 cases, much faster than the inference speeds of the clinicians, ranging from 177.2 ± 28.0 s/40 cases to 241.2 ± 64.1 s/40 cases.

CONCLUSIONS

Our algorithm demonstrated comparable or even better performance compared to clinicians in assessing spine growth potential. This stable, efficient, and convenient algorithm seems to be a promising approach to assist doctors in clinical practice and deserves further study.

CLINICAL RELEVANCE STATEMENT

This method has the ability to quickly ascertain the spine growth potential based on EOS radiographs, and it holds promise to provide assistance to busy doctors in certain clinical scenarios.

KEY POINTS

• In the clinic, there is no available computer-based method that can automatically assess spine growth potential. • We developed a deep learning-based method that could automatically ascertain spine growth potential. • Compared with the results of the clinicians, our algorithm got comparable results.

Substantial mismatch of skeletal maturity assessment between Risser sign and Simplified Skeletal Maturity Scale/Thumb Ossification Composite Index in patients with adolescent idiopathic scoliosis

BACKGROUND

Recently, hand skeletal maturity systems such as the Simplified Skeletal Maturity Scale (SSMS) or Thumb Ossification Composite Index (TOCI) have been introduced to attempt to prospectively predict the occurrence of peak height velocity (PHV) in adolescents. This study aims to compare the frequency of the mismatch in estimation of HV between Risser sign (RS) and SSMS/TOCI stages in adolescent idiopathic scoliosis (AIS) patients.

METHODS

One hundred thirty-three female patients with AIS were included. The mean age of the patients was 13.1 years. A whole spine and hand X-rays were obtained to establish skeletal maturity stage according to RS, SSMS, and TOCI systems. A mismatch resulting in overestimation (MOE) with RS compared to SSMS/TOCI was defined as the combination of RS 3-4/SSMS 3-5 or RS 3-4/TOCI 4-6, whereas a mismatch resulting in underestimation (MUE) with RS and SSMS/TOCI was defined as RS 0-1/SSMS 6-8 or RS 0-1/TOCI 7-8. Height velocity (HV) was compared between MOE/non-MOE and MUE/non-MUE groups.

RESULTS

Between RS and SSMS, the rates of the MOE and MUE groups were 4.3% and 1.7%, respectively. Between RS and TOCI, rates were 2.8% and 1.7%, respectively. With the combination of RS and SSMS stages, an estimate of HV of 5.6 cm/year in the MOE group was significantly larger than that of 2.7 cm/year in the non-MOE group, and 3.7 cm/year in the MUE group was significantly smaller than 6.9 cm/year in the non-MUE group. Likewise, with the combination of RS and TOCI stages, an estimate of HV of 5.8 cm/year in the MOE group was significantly greater that of 2.7 cm/year in the non-MOE group, and 3.7 cm/year in the MUE group was significantly smaller than 6.9 cm/year in the non-MUE group.

CONCLUSIONS

These findings support the use of SSMS/TOCI as the standard for assessing HV and skeletal maturity in patients with AIS.

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.

Does the Use of Sanders Staging and Distal Radius and Ulna Classification Avoid Mismatches in Growth Assessment with Risser Staging Alone?

BACKGROUND

Although Risser stages are visible on the same radiograph of the spine, Risser staging is criticized for its insensitivity in estimating the remaining growth potential and its weak correlation with curve progression in patients with adolescent idiopathic scoliosis. Risser staging is frequently accompanied by other skeletal maturity indices to increase its precision for assessing pubertal growth. However, it remains unknown whether there is any discrepancy between various maturity parameters and the extent of this discrepancy when these indices are used concurrently to assess pubertal growth landmarks, which are important for the timing of brace initiation and weaning.

QUESTIONS/PURPOSES

(1) What is the chronologic order of skeletal maturity grades based on the growth rate and curve progression rate in patients with adolescent idiopathic scoliosis? (2) What are the discrepancies among the grades of each maturity index for indicating the peak growth and start of the growth plateau, and how do these indices correspond to each other? (3) What is the effectiveness of Risser staging, Sanders staging, and the distal radius and ulna classification in assessing peak growth and the beginning of the growth plateau?

METHODS

Between 2014 and 2017, a total of 13,536 patients diagnosed with adolescent idiopathic scoliosis were treated at our tertiary clinic. Of those, 3864 patients with a radiograph of the left hand and wrist and a posteroanterior radiograph of the spine at the same visits including initial presentation were considered potentially eligible for this study. Minimum follow-up was defined as 6 months from the first visit, and the follow-up duration was defined as 2 years since initial consultation. In all, 48% (1867 of 3864) of patients were eligible, of which 26% (485 of 1867) were excluded because they were prescribed bracing at the first consultation. These patients visited the subsequent clinics wearing the brace, which might have affected body height measurement. Six percent (117 of 1867) of eligible patients were also excluded as their major coronal Cobb angle reached the surgical threshold of 50° and had undergone surgery before skeletal maturity. Another 21% (387 of 1867) of patients were lost before minimum follow-up or had incomplete data, leaving 47% (878) for analysis. These 878 patients with 1139 skeletal maturity assessments were studied; 74% (648 of 878) were girls. Standing body height was measured in a standardized manner by a wall-mounted stadiometer. Several surgeons measured curve magnitude as per routine clinical consultation, skeletal maturity was measured according to the distal radius and ulna classification, and two raters measured Risser and Sanders stages. Reliability tests were performed with satisfaction. Data were collected for the included patients at multiple points when skeletal maturity was assessed, and only up to when brace wear started for those who eventually had bracing. The growth rate and curve progression rate were calculated by the change of body height and major coronal Cobb angle over the number of months elapsed between the initial visit and next follow-up. At each skeletal maturity grading, we examined the growth rate (in centimeters per month) and curve progression rate (in degrees per month) since the skeletal maturity assessment, as well as the mean age at which this maturity grading occurred. Each patient was then individually assessed for whether he or she was experiencing peak growth and the beginning of growth plateau at each timepoint by comparing the calculated growth rate with the previously defined peak growth rate of ≥ 0.7 cm per month and the beginning of growth plateau rate of ≤ 0.15 cm per month in this adolescent idiopathic scoliosis population. Among the timepoints at which the peak growth and the beginning of growth plateau occurred, the median maturity grade of each maturity index was identified as the benchmark grade for comparison between indices. We used the McNemar test to investigate whether pubertal growth landmarks were identified by specific maturity grades concurrently. We assessed the effectiveness of these skeletal maturity indices by the difference in proportions (%) between two benchmark grades in indicating peak growth and the growth plateau.

RESULTS

For girls, the chronological order of maturity grades that indicated peak growth was the radius grade, ulna grade, Sanders stage, and Risser stage. Curve progression peaked between the age of 11.6 and 12.1 years at a similar timing by all maturity indices for girls but was inconsistent for boys. For both sexes, radius (R) grade 6, ulna (U) grade 5, Sanders stage (SS) 3, and Risser stage 0+ were the median grades for peak growth, whereas Risser stage 4, R8/9, U7/8, and SS6/7 indicated the beginning of the growth plateau. The largest discrepancy between maturity indices was represented by Risser stage 0+, which corresponded to six grades of the Sanders staging system (SS2 to SS7) and to R6 in only 41% (62 of 152) of girls in the whole cohort. Despite Risser stage 0+ corresponding to the wide range of Sanders and distal radius and ulna grades, none of the R6, U5, SS3, and Risser stage 0+ was found more effective than another grade in indicating the peak growth in girls. R6 most effectively indicated the peak growth in boys, and Risser stage 0+ was the least effective. For the beginning of the growth plateau in girls, SS6/7 was the most effective indicator, followed by U7/8. Risser stage 4 was the least effective because it indicated 29% (95% CI 21% to 36%; p < 0.001) fewer patients who reached the beginning of the growth plateau than did those with R8/9. Risser stage 4 also indicated 36% (95% CI 28% to 43%; p < 0.001) fewer patients who reached the beginning of the growth plateau than those indicated by U7/8, and it identified 39% fewer patients than SS6/7 (95% CI 32% to 47%; p < 0.001). For boys, similarly, R8/9, U7/8, and SS6/7 were all more effective than Risser stage 4 in identifying when the growth plateau began.

CONCLUSION

Risser stage 0+ corresponds to a wide range of Sanders and distal radius and ulna grades. Risser stage 0+ is least effective in indicating the peak growth in boys, and Risser stage 4 is the least effective maturity grade for indicating when the growth plateau starts in both sexes. The concurrent use of R6 and SS3 can be useful for detecting the peak growth, and SS6/7 in conjunction with U7/8 is most effective in indicating the beginning of the growth plateau. Using a combination of specific grades of Sanders staging and the distal radius and ulna classification can indicate pubertal growth landmarks with reduced risk of underestimating or overestimating skeletal maturity. These findings may aid in refining clinical decision-making of brace initiation and weaning at a more precise timing. Among Risser stage 0, the appearance of R6, U5, and SS3 provide the most effective assessment of peak growth that can indicate the most effective bracing period within which curve progression occurs. For initiation of the growth plateau, Risser 4 is not useful, and SS6/7, R8/9 and U7/8 should be used instead.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Automatic bone maturity grading from EOS radiographs in Adolescent Idiopathic Scoliosis

Adolescent Idiopathic Scoliosis (AIS) is a deformation of the spine and it is routinely diagnosed using posteroanterior and lateral radiographs. The Risser sign used in skeletal maturity assessment is commonly accepted in AIS patient's management. However, the Risser sign is subject to inter-observer variability and it relies mainly on the observation of ossification on the iliac crests. This study proposes a new machine-learning-based approach for Risser sign skeletal maturity assessment using EOS radiographs. Regions of interest including right and left humeral heads; left and right femoral heads; and pelvis are extracted from the radiographs. First, a total of 24 image features is extracted from EOS radiographs using a ResNet101-type convolutional neural network (CNN), pre-trained from the ImageNet database. Then, a support vector machine (SVM) algorithm is used for the final Risser sign classification. The experimental results demonstrate an overall accuracy of 84%, 78%, and 80% respectively for iliac crests, humeral heads, and femoral heads. Class activation maps using Grad-CAM were also investigated to understand the features of our model. In conclusion, our machine learning approach is promising to incorporate a large number of image features for different regions of interest to improve Risser grading for skeletal maturity. Automatic classification could contribute to the management of AIS patients.

Reproducibility and reliability analysis of the Luk Distal Radius and Ulna Classification for European patients with adolescent idiopathic scoliosis

PURPOSE

Current clinical and radiological methods of predicting a patient's growth potential are limited in terms of practicality, accuracy and known to differ in different races. This information influences optimal timing of bracing and surgical intervention in adolescent idiopathic scoliosis (AIS). The Luk classification was developed to mitigate limitations of existing tools. Few reliability studies are available and are limited to certain geographical regions with varying results. This study was performed to analyze reproducibility and reliability of the Luk Distal Radius and Ulna Classification in European patients.

METHODS

This is a radiological study of 50 randomly selected left hand and wrist radiographs of patients with AIS referred to a tertiary referral centre. They were assessed for bone maturity using the Luk Distal Radius and Ulna Classification. Assessment was performed twice by four examiners at an interval of one month. Statistical analysis was performed using the intraclass correlation (ICC) method to determine the reliabilities within and between the examiners.

RESULTS

In total, 50 radiographs (M:F = 13:37) with a mean age of 13.7 years (10 to 18) were assessed for reliability. The inter-rater ICC value was 0.918 for radius assessment and 0.939 for ulna assessment. The intra-rater ICC values for radius assessment ranged between 0.897 and 0.769 and between 0.948 and 0.786 for ulna assessment. There was near perfect correlation for both assessments.

CONCLUSION

This study provides independent evidence that the Luk Distal Radius and Ulna Classification is a reliable tool for assessment of skeletal maturity for European patients. Minimal clinical experience is required to reliably utilize it.

LEVEL OF EVIDENCE

IV.

A Simplified Skeletal Maturity Scale and Thumb Ossification Composite Index to Assess Skeletal Maturity and Predict Height Velocity in Japanese Females with Adolescent Idiopathic Scoliosis

INTRODUCTION

Since Little et al. first reported that peak height velocity (PHV) could be described as a reliable clinical marker for the prediction of remaining growth and curve progression of adolescent idiopathic scoliosis (AIS) in clinical practice, much attention has been paid to PHV as a possible predictor of curve progression in patients with AIS. However, PHV itself is only identified retrospectively, so its value is not available at the first outpatient clinic visit. Using the simplified skeletal maturity scale (SSMS) and the thumb ossification composite index (TOCI) staging systems, this study aims to assess skeletal maturity and predict height velocity (HV) in Japanese female patients with AIS.

METHODS

This study involved 95 female patients with AIS, ranging from 9 to 17 years old. A standing AP radiograph of the entire spine and a hand radiograph were retrospectively obtained to establish the skeletal maturity stage in accordance with the SSMS and TOCI systems. Height measurements were recorded at each visit; HV was calculated as the height change (cm) divided by the time interval (years).

RESULTS

The TOCI stage rating increased identically to the SSMS stage rating increase. The chi-square test showed that there was a significant correlation between the two scoring systems (χ2=720.4). The Cramer V correlation also demonstrated a very strong correlation (Cramer V=0.62). Regarding the relationship between HV and each SSMS and TOCI stage, HV decreased as SSMS and TOCI stages increased. η 2 equaled to 0.67 in both groups and displayed a strong correlation between HV and SSMS and TOCI stages.

CONCLUSIONS

These findings suggest that evaluation of the rate of HV using these radiological assessments is of supreme importance for determining the status of pubertal maturity and predicting the remaining amount of adolescent growth at the outpatient clinic visit.

Convolutional Neural Networks for Automatic Risser Stage Assessment

PURPOSE

To develop an automatic method for the assessment of the Risser stage using deep learning that could be used in the management panel of adolescent idiopathic scoliosis (AIS).

MATERIALS AND METHODS

In this institutional review board approved-study, a total of 1830 posteroanterior radiographs of patients with AIS (age range, 10-18 years, 70% female) were collected retrospectively and graded manually by six trained readers using the United States Risser staging system. Each radiograph was preprocessed and cropped to include the entire pelvic region. A convolutional neural network was trained to automatically grade conventional radiographs according to the Risser classification. The network was then validated by comparing its accuracy against the interobserver variability of six trained graders from the authors' institution using the Fleiss κ statistical measure.

RESULTS

Overall agreement between the six observers was fair, with a κ coefficient of 0.65 for the experienced graders and agreement of 74.5%. The automatic grading method obtained a κ coefficient of 0.72, which is a substantial agreement with the ground truth, and an overall accuracy of 78.0%.

CONCLUSION

The high accuracy of the model presented here compared with human readers suggests that this work may provide a new method for standardization of Risser grading. The model could assist physicians with the task, as well as provide additional insights in the assessment of bone maturity based on radiographs.© RSNA, 2020.

Does Curve Regression Occur During Underarm Bracing in Patients with Adolescent Idiopathic Scoliosis?

BACKGROUND

Successful brace treatment entails good control of scoliosis with avoidance of surgery. However, achieving curve regression may be an even better radiological result than prevention of curve progression for patients with adolescent idiopathic scoliosis. Vertebral remodeling may occur with well-fitted braces. Better in-brace curve correction may influence the likelihood of vertebral remodeling and the chance of curve regression. Only a few reports have evaluated curve regression with brace treatment, and the factors associated with these events are unknown.

QUESTIONS/PURPOSES

(1) What changes in curvature are observed with brace treatment for adolescent idiopathic scoliosis? (2) What factors are associated with curve improvement? (3) What factors are associated with curve deterioration? (4) Is curve regression associated with improvements in patient-reported objective outcome scores?

METHODS

Between September 2008 and December 2013, 666 patients with adolescent idiopathic scoliosis underwent underarm brace treatment and were followed until skeletal maturity at 18 years old. Among these patients, 80 were excluded because of early discontinuation of brace treatment (n = 66) and loss to follow-up (n = 14). Hence, 586 patients were included in this study, with a mean brace-wear duration of 3.8 ± 1.5 years and post-weaning follow-up duration of 2.0 ± 1.1 years. The mean age at baseline was 12.6 ± 1.2 years. Most patients were female (87%, 507 of 586) and up to 53% (267 of 507) of females were post-menarche. Bracing outcomes were based on changes in the Cobb angle measured out of brace. These included curve regression, as indicated by at least a 5° reduction in the Cobb angle, curve progression, as indicated by at least a 5° increase in the Cobb angle, and unchanged, as indicated by a change in the Cobb angle of less than 5°. We studied the pre-brace and supine Cobb angles, curve flexibility (pre-brace Cobb angle - supine Cobb angle / pre-brace Cobb angle x 100%), correction rate (pre-brace Cobb angle - in-brace Cobb angle / pre-brace Cobb angle x 100%), location of apical vertebrae, apical ratio (convex vertebral height/concave vertebral height), change in the major curve Cobb angle, and apical ratio post-bracing. The refined 22-item Scoliosis Research Society questionnaire was used for patient-reported outcomes and is composed of five domains (function, pain, appearance, mental health and satisfaction with treatment). Its minimum clinically important difference, based on a scale from 0 to 5, has been quoted as 0.2 for pain, 0.08 for activity and 0.98 for appearance domains. Mental health has no quoted minimum clinically important difference for the adolescent idiopathic scoliosis population. Satisfaction with treatment is described based on improvement or deterioration in domain scores. Intergroup differences between bracing outcomes were evaluated with the Kruskal Wallis test. Univariate analyses of bracing outcomes were performed with a point-biserial correlation coefficient for continuous variables and Pearson's chi-square test for categorical variables. Multivariate logistic regression models were created for improved and deteriorated outcomes. P values < 0.05 were considered significant.

RESULTS

In all, 17% of patients (98 of 586) had an improved angle and 40% of patients (234 of 586) had curve deterioration. In patients who improved, the mean reduction in the Cobb angle was 9 ± 4°, while in patients who deteriorated, the mean increase in the Cobb angle was 15 ± 9°, and this was maintained at the latest post-brace weaning follow-up. Despite a trend for patients with curve regression to have higher baseline flexibility and correction rate, after controlling for age, Risser staging, radius and ulnar grading, and Sanders staging, we found no clinically important differences with increased correction rate or flexibility. We did find that improvement in the Cobb angle after bracing was associated with reduced apical ratio (odds ratio [OR] 0.84 [95% CI 0.80 to 0.87]; p < 0.001). Curve progression was associated with younger age (OR 0.71 [95% CI 0.55 to 0.91]; p = 0.008), pre-menarche status (OR 2.46 [95% CI 1.31 to 4.62]; p = 0.005), and increased apical ratio (OR 1.24 [95% CI 1.19 to 1.30]; p < 0.001) but no clinically important differences were observed with less flexible curves and reduced correction rate. Improvements in scores of the refined 22-item Scoliosis Research Society domains of function (mean difference on a scale from 0 to 5: 0.2; p = 0.001 versus 0.1; p < 0.001) and pain (mean difference on a scale from 0 to 5: 0.2; p = 0.020 versus 0.0; p = 0.853) were greater in the post-brace improvement group than in the deterioration group and fulfilled the minimum clinically important difference threshold. The appearance domain did not fulfill the minimum clinically important difference. Satisfaction with treatment domain score minimally improved with the curve regression group (mean difference on a scale from 0 to 5: 0.2) but deteriorated in the curve progression group (mean difference on a scale from 0 to 5: -0.4).

CONCLUSIONS

Curve regression occurs after underarm bracing and is associated with superior patient-reported outcome scores. This possible change in Cobb angle should be explained to patients before and during bracing. Whether this may help improve patients' duration of brace-wear should be addressed in future studies. Patients with well-fitting braces may experience curve improvement and possible vertebral remodeling. Those braced at a younger age and with increased vertebral wedging are more likely to have curve progression.

LEVEL OF EVIDENCE

Level III, therapeutic study.

High Risk of Mismatch Between Sanders and Risser Staging in Adolescent Idiopathic Scoliosis: Are We Guiding Treatment Using the Wrong Classification?

BACKGROUND

Despite known limitations, Risser staging has traditionally been the primary marker of skeletal maturity utilized in decision-making for treatment of adolescent idiopathic scoliosis (AIS). The purpose of this study is to assess the incidence and factors associated with mismatch between Risser Staging and Sanders classification, and determine interobserver reliability.

METHODS

We reviewed the medical records of consecutive patients aged 10 to 18 referred to our institution for evaluation of AIS from January to June 2016 with a closed triradiate cartilage. Data collected included sex, age, race, height, weight, body mass index percentile, menarchal status, Risser stage, Sanders classification, and major curve. Risser and Sanders stage was determined by 2 fellowship-trained pediatric spine surgeons and 1 pediatric orthopaedic nurse practitioner. Mismatch was defined as Risser stage 2 to 4 corresponding to Sanders 3 to 5, and Risser 0 to 1 corresponding to Sanders 6 to 7.

RESULTS

A total of 165 consecutive patients were identified (mean age: 13.9±1.7 y, major curve 28.2±15.4 degrees, 76% female). The risk of skeletal maturity mismatch, based on the criteria of Risser 2 to 5 (limited growth remaining) corresponding to Sanders 3 to 5 (significant growth remaining) was 21.8%, indicating that 1 of 5 patients would be undertreated if managed by Risser criteria. Conversely, the mismatch risk for Risser 0 to 1 corresponding to Sanders 6 to 7 was 3.6%, leading such patients to be treated conservatively longer than necessary. Males and those of Hispanic ethnicity were at a higher risk of mismatch (23.1% vs. 11.9%, P=0.08; 33.3% vs. 8.8%, P=0.04, respectively). Body mass index percentile, race, and major curve were not associated with mismatch. The unweighted and weighted interobserver κ for Risser staging was 0.74 and 0.82, respectively, and 0.86 and 0.91 for Sanders classification, respectively.

CONCLUSION

Given the limited sensitivity of Risser staging during peak growth velocity, high mismatch risk, and lower interobserver reliability, the Sanders classification should be utilized to guide treatment options in patients with AIS. Compared with Sanders, utilizing Risser staging results in mistreatment in a total of 1 of 4 patients, with the vast majority being undertreated.

LEVEL OF EVIDENCE

Level II.

APSS-ASJ Best Clinical Research Award: Predictability of Curve Progression in Adolescent Idiopathic Scoliosis Using the Distal Radius and Ulna Classification

Study Design

Prospective study.

Purpose

To determine the risk of clinically significant curve progression in adolescent idiopathic scoliosis (AIS) based on the initial Cobb angle and to test the utility of the distal radius and ulna (DRU) classification in predicting these outcomes.

Overview of Literature

Determining the remaining growth potential in AIS patients is necessary for predicting prognosis and initiating treatment. Limiting the maturity Cobb angle to <40° and <50° reduces the risk of adulthood progression and need for surgery, respectively. The risk of curve progression is the greatest with skeletally immature patients and thus warrants close monitoring or early intervention. Many parameters exist for measuring the skeletal maturity status in AIS patients, but the DRU classification has been shown to be superior in predicting peak growth and growth cessation. However, its predictive capabilities for curve progression are unknown.

Methods

Totally, 513 AIS patients who presented with Risser 0–3 were followed until either skeletal maturity or the need for surgery, with a minimum 2-year follow-up period. Outcomes of 40° and 50° were used for probability analysis based on the cut-offs of adulthood progression risk and surgical threshold, respectively.

Results

At the R6/U5 grade, most curves (probability of ≥48.1%–55.5%) beyond a Cobb angle of 25° progressed to the 40° threshold. For curves of ≥35°, there was a high risk of unfavorable outcomes, regardless of skeletal maturity. Most patients with the R9 grade did not progress, regardless of the initial curve magnitude (probability of 0% to reach the 50° threshold for an initial Cobb angle of ≥35°).

Conclusions

This large-scale study illustrates the utility of the DRU classification for predicting curve progression and how it may effectively guide the timing of surgery. Bracing may be indicated for skeletally immature patients at an initial Cobb angle of 25°, and those with a scoliosis ≥35° are at an increased risk of an unfavorable outcome, despite being near skeletal maturity.

2016 SOSORT guidelines: orthopaedic and rehabilitation treatment of idiopathic scoliosis during growth

BACKGROUND

The International Scientific Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT) produced its first guidelines in 2005 and renewed them in 2011. Recently published high-quality clinical trials on the effect of conservative treatment approaches (braces and exercises) for idiopathic scoliosis prompted us to update the last guidelines' version. The objective was to align the guidelines with the new scientific evidence to assure faster knowledge transfer into clinical practice of conservative treatment for idiopathic scoliosis (CTIS).

METHODS

Physicians, researchers and allied health practitioners working in the area of CTIS were involved in the development of the 2016 guidelines. Multiple literature reviews reviewing the evidence on CTIS (assessment, bracing, physiotherapy, physiotherapeutic scoliosis-specific exercises (PSSE) and other CTIS) were conducted. Documents, recommendations and practical approach flow charts were developed using a Delphi procedure. The process was completed with the Consensus Session held during the first combined SOSORT/IRSSD Meeting held in Banff, Canada, in May 2016.

RESULTS

The contents of the new 2016 guidelines include the following: background on idiopathic scoliosis, description of CTIS approaches for various populations with flow-charts for clinical practice, as well as literature reviews and recommendations on assessment, bracing, PSSE and other CTIS. The present guidelines include a total of 68 recommendations divided into following topics: bracing (n = 25), PSSE to prevent scoliosis progression during growth (n = 12), PSSE during brace treatment and surgical therapy (n = 6), other conservative treatments (n = 2), respiratory function and exercises (n = 3), general sport activities (n = 6); and assessment (n = 14). According to the agreed strength and level of evidence rating scale, there were 2 recommendations on bracing and 1 recommendation on PSSE that reached level of recommendation "I" and level of evidence "II". Three recommendations reached strength of recommendation A based on the level of evidence I (2 for bracing and one for assessment); 39 recommendations reached strength of recommendation B (20 for bracing, 13 for PSSE, and 6 for assessment).The number of paper for each level of evidence for each treatment is shown in Table 8.

CONCLUSION

The 2016 SOSORT guidelines were developed based on the current evidence on CTIS. Over the last 5 years, high-quality evidence has started to emerge, particularly in the areas of efficacy of bracing (one large multicentre trial) and PSSE (three single-centre randomized controlled trials). Several grade A recommendations were presented. Despite the growing high-quality evidence, the heterogeneity of the study protocols limits generalizability of the recommendations. There is a need for standardization of research methods of conservative treatment effectiveness, as recognized by SOSORT and the Scoliosis Research Society (SRS) non-operative management Committee.

Managing the Pediatric Spine: Growth Assessment

Management of pediatric spinal deformities requires an accurate prediction of growth spurts to allow for timely initiation of treatment and prevention of curve progression. Determining remaining growth potential is also important for avoiding prolonged unnecessary treatment, e.g. bracing for patients nearing skeletal maturity. Many clinical and radiological growth parameters have been developed to aid clinicians in growth prediction. Of these, several commonly used measures such as height and arm span growth trends, timing of menarche, and the Risser sign are mostly retrospective and lack strong predictive utility. Bone age assessments, such as digital skeletal age and the distal radius and ulna classification, are more accurate parameters, but further research is required to determine interethnic variations and develop their role in management decisions.

The iliac crest in forensic age estimation: evaluation of three methods in pelvis X-rays

Age assessment in children and young adults is a relevant forensic issue. It is requested not only in evaluating criminal responsibility in youths without proper identification documents, often in relation to age thresholds, but also for release of a residency permit, and asylum seekers of minors. The analysis of the Risser sign and the iliac crest ossification process has been proposed as a useful tool for forensic age estimation. We evaluated the applicability of three different age estimation methods on a sample of 497 pelvic radiographs of Italian individuals between 10 and 25 years of age. Each method showed high reliability for both reproducibility and repeatability. The staging technique inspired by Kreitner and Kellinghaus methods (KK-MS) is easier than the Risser method in applicability, as it is not affected by the variations of ossification. We observed that all subjects who attained stage 3c of KK-MS and 5 of Risser Fr were >14 years, suggesting the benefits of these methods for that age threshold. The applicability of the area measurement method, inspired by Cameriere's approach, ranged between 12 and 20 years, but the statistical analysis showed only a moderate correlation with age. In order to evaluate the possible use of this approach it is therefore necessary to clarify and exclude external factors influencing the parameter. In conclusion, the iliac crest ossification is of interest in age estimation for forensic purposes. The evaluation of the pelvis X-ray, in addition to the other common dental and skeletal methods, could become a useful supplementary tool in age estimation for the 14 year threshold in order to fulfill forensic-level requirements.

The use of the distal radius and ulna classification for the prediction of growth: peak growth spurt and growth cessation

AIMS

We report the use of the distal radius and ulna (DRU) classification for the prediction of peak growth (PG) and growth cessation (GC) in 777 patients with idiopathic scoliosis. We compare this classification with other commonly used parameters of maturity.

PATIENTS AND METHODS

The following data were extracted from the patients' records and radiographs: chronological age, body height (BH), arm span (AS), date of menarche, Risser sign, DRU grade and status of the phalangeal and metacarpal physes. The mean rates of growth were recorded according to each parameter of maturity. PG was defined as the summit of the curve and GC as the plateau in deceleration of growth. The rates of growth at PG and GC were used for analysis using receiver operating characteristic (ROC) curves to determine the strength and cutoff values of the parameters of growth.

RESULTS

The most specific grades for PG using the DRU classification were radial grade 6 and ulnar grade 5, and for GC were radial grade 9 and ulnar grade 7. The DRU classification spanned both PG and GC, enabling better prediction of these clinically relevant stages than other methods. The rate of PG (≥ 0.7 cm/month) and GC (≤ 0.15 cm/month) was the same for girls and boys, in BH and AS measurements.

CONCLUSION

This is the first study to note that the DRU classification can predict both PG and GC, providing evidence that it may aid the management of patients with idiopathic scoliosis. Cite this article: Bone Joint J 2016;98-B:1689-96.

Reliability Analysis of the Distal Radius and Ulna Classification for Assessing Skeletal Maturity for Patients with Adolescent Idiopathic Scoliosis

Study Design Prospective radiographic study. Objective To test the reliability of the Distal Radius and Ulna Classification (DRU). Methods This single-center study included prospectively recruited subjects with adolescent idiopathic scoliosis managed with bracing. The left-hand radiographs were measured using the DRU classification by two examiners. Intra- and interobserver reliability analysis were performed using intraclass correlation (ICC) analysis. Results From these clinics, 161 patients (124 females and 37 males) with left-hand radiographs were included in the study. The mean age was 13.3 years (standard deviation: 1.5). There was excellent intra- (ICC: 0.93 to 0.95) and interobserver (ICC: 0.97) reliability. Conclusions The DRU classification scheme has been shown to be accurate in determining the peak growth phase and growth cessation. It has now been confirmed to be a reliable tool. Future prospective studies should be performed to investigate its application in deciding when to apply bracing or operative treatment.

Prediction of Curve Progression in Idiopathic Scoliosis: Validation of the Sanders Skeletal Maturity Staging System

STUDY DESIGN

Retrospective case series.

OBJECTIVE

This study aimed to validate the Sanders Skeletal Maturity Staging System and to assess its correlation to curve progression in idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

The Sanders Skeletal Maturity Staging System has been used to predict curve progression in idiopathic scoliosis. This study intended to validate that initial study with a larger sample size.

METHODS

We retrospectively reviewed 1100 consecutive patients with idiopathic scoliosis between 2005 and 2011. Girls aged 8 to 14 years (<2 yr postmenarche) and boys aged 10 to 16 years who had obtained at least 1 hand and spine radiograph on the same day for evaluation of skeletal age and scoliosis curve magnitude were followed to skeletal maturity (Risser stage 5 or fully capped Risser stage 4), curve progression to 50° or greater, or spinal fusion. Patients with nonidiopathic curves were excluded.

RESULTS

There were 161 patients: 131 girls (12.3 ± 1.2 yr) and 30 boys (13.9 ± 1.1 yr). The distribution of patients within Sanders stage (SS) 1 through 7 was 7, 28, 41, 45, 7, 31, and 2 patients, respectively; modified Lenke curve types 1 to 6 were 26, 12, 63, 5, 38, and 17 patients, respectively. All patients in SS2 with initial Cobb angles of 25° or greater progressed, and patients in SS1 and SS3 with initial Cobb angles of 35° or greater progressed. Similarly, all patients with initial Cobb angles of 40° or greater progressed except those in SS7. Conversely, none of the patients with initial Cobb angles of 15° or less or those in SS5, SS6, and SS7 with initial Cobb angles of 30° or less progressed. Predictive progression of 67%, 50%, 43%, 27%, and 60% was observed for subgroups SS1/30°, SS2/20°, SS3/30°, SS4/30°, and SS6/35° respectively.

CONCLUSION

This larger cohort shows a strong predictive correlation between SS and initial Cobb angle for probability of curve progression in idiopathic scoliosis.

LEVEL OF EVIDENCE

3.

Recommendations for research studies on treatment of idiopathic scoliosis: Consensus 2014 between SOSORT and SRS non-operative management committee

The two main societies clinically dealing with idiopathic scoliosis are the Scoliosis Research Society (SRS), founded in 1966, and the international Society on Scoliosis Orthopedic and Rehabilitation Treatment (SOSORT), started in 2004. Inside the SRS, the Non-Operative Management Committee (SRS-NOC) has the same clinical interest of SOSORT, that is the Orthopaedic and Rehabilitation (or Non-Operative, or conservative) Management of idiopathic scoliosis patients. The aim of this paper is to present the results of a Consensus among the best experts of non-operative treatment of Idiopathic Scoliosis, as represented by SOSORT and SRS, on the recommendation for research studies on treatment of Idiopathic Scoliosis. The goal of the consensus statement is to establish a framework for research with clearly delineated inclusion criteria, methodologies, and outcome measures so that future meta- analysis or comparative studies could occur. A Delphi method was used to generate a consensus to develop a set of recommendations for clinical studies on treatment of Idiopathic Scoliosis. It included the development of a reference scheme, which was judged during two Delphi Rounds; after this first phase, it was decided to develop the recommendations and 4 other Delphi Rounds followed. The process finished with a Consensus Meeting, that was held during the SOSORT Meeting in Wiesbaden, 8-10 May 2014, moderated by the Presidents of SOSORT (JP O'Brien) and SRS (SD Glassman) and by the Chairs of the involved Committees (SOSORT Consensus Committee: S Negrini; SRS Non-Operative Committee: MT Hresko). The Boards of the SRS and SOSORT formally accepted the final recommendations. The 18 Recommendations focused: Research needs (3), Clinically significant outcomes (4), Radiographic outcomes (3), Other key outcomes (Quality of Life, adherence to treatment) (2), Standardization of methods of non-operative research (6).

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.

Progression or not progression? How to deal with adolescent idiopathic scoliosis during puberty

Idiopathic scoliosis is a growing spine disorder. Only a perfect knowledge of normal growth parameters such as bone age, stages of puberty, standing and sitting height, arm spam, Tanner stages, and weight allow the surgeon to plan the best treatment at the right moment. Measurements should be repeated and carefully recorded at regular intervals. Puberty is not a sudden event: it has a gradual onset and it is preceded by an incubation phase. It is not a point on a chart: it is a period that lasts two years beginning at a bone age of 11 and 13 years in girls and in boys, respectively. Two years of rapid growth ("acceleration phase") are followed by three years of steady reduction of growth rates ("deceleration phase"). Skeletal maturation needs to be evaluated carefully to evaluate the progression risk of scoliosis during the phase of accelerating growth velocity. This article explains how to identify pubertal growth spurt, both clinically and radiographically, in order to correctly monitor patients with idiopathic scoliosis.

The Risser sign for forensic age estimation in living individuals: a study of 643 pelvic radiographs

Due to increasing international migratory movements, forensic age estimations of living individuals in criminal proceedings are gaining increasing significance for forensic physicians and radiologists involved in delivering expert opinions. The present study examines the suitability of the radiologically well-known Risser sign grading as a possible new criterion in forensic age diagnostics. For this purpose, anteroposterior pelvic radiographs of 643 patients aged between 10 and 30 years were retrospectively evaluated by means of two different Risser sign grading systems (US and French), each with 5 stages. The left and right sides of the pelvis were assessed separately. The data was analyzed with separation of the sexes. Reliable Risser sign determination was possible in 566 cases. In both sexes, stage 4 of both the US and the French grading systems was predominantly first noted at age 14 years. In the US grading system, stage 5 was also first achieved at age 14 years in the majority of both sexes. In the French grading system, females manifested stage 5 at a minimum of 16 years, whereas in males it was first observed at 17 years. As to the nature of iliac crest maturation, interesting deviations were observed at stages 1 and 5, raising doubts about Risser's ossification process. To conclude, both Risser sign grading systems are suitable for forensic age diagnostics, especially to determine whether the 14th year of life has been completed or not. The French Risser sign system additionally allows for statements as to the completion of the 16th year of age.

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.

2011 SOSORT guidelines: Orthopaedic and Rehabilitation treatment of idiopathic scoliosis during growth

BACKGROUND

The International Scientific Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT), that produced its first Guidelines in 2005, felt the need to revise them and increase their scientific quality. The aim is to offer to all professionals and their patients an evidence-based updated review of the actual evidence on conservative treatment of idiopathic scoliosis (CTIS).

METHODS

All types of professionals (specialty physicians, and allied health professionals) engaged in CTIS have been involved together with a methodologist and a patient representative. A review of all the relevant literature and of the existing Guidelines have been performed. Documents, recommendations, and practical approach flow charts have been developed according to a Delphi procedure. A methodological and practical review has been made, and a final Consensus Session was held during the 2011 Barcelona SOSORT Meeting.

RESULTS

The contents of the document are: methodology; generalities on idiopathic scoliosis; approach to CTIS in different patients, with practical flow-charts; literature review and recommendations on assessment, bracing, physiotherapy, Physiotherapeutic Specific Exercises (PSE) and other CTIS. Sixty-five recommendations have been given, divided in the following topics: Bracing (20 recommendations), PSE to prevent scoliosis progression during growth (8), PSE during brace treatment and surgical therapy (5), Other conservative treatments (3), Respiratory function and exercises (3), Sports activities (6), Assessment (20). No recommendations reached a Strength of Evidence level I; 2 were level II; 7 level III; and 20 level IV; through the Consensus procedure 26 reached level V and 10 level VI. The Strength of Recommendations was Grade A for 13, B for 49 and C for 3; none had grade D.

CONCLUSION

These Guidelines have been a big effort of SOSORT to paint the actual situation of CTIS, starting from the evidence, and filling all the gray areas using a scientific method. According to results, it is possible to understand the lack of research in general on CTIS. SOSORT invites researchers to join, and clinicians to develop good research strategies to allow in the future to support or refute these recommendations according to new and stronger evidence.

Abnormal anthropometric measurements and growth pattern in male adolescent idiopathic scoliosis

PURPOSE

The progression of adolescent idiopathic scoliosis is closely correlated with longitudinal growth during puberty. A decreased incidence of curve progression has been found in male patients with adolescent idiopathic scoliosis compared with female patients with the condition. This finding implies that there might be a sexual dimorphism in the pubertal growth patterns of adolescent idiopathic scoliosis patients. Abnormal pubertal growth in female adolescent idiopathic scoliosis patients has been well characterized; however, the pubertal growth patterns of male adolescent idiopathic scoliosis patients have not been reported. We conducted a cross-sectional study of anthropometric measurements to compare the growth patterns of male patients with adolescent idiopathic scoliosis with those of healthy boys during puberty and explore the difference in the pubertal growth patterns of female and male patients with adolescent idiopathic scoliosis.

METHODS

A total of 688 subjects were involved in the study, including 332 male adolescent idiopathic scoliosis patients and 356 age-matched healthy boys. The subjects were categorized according to their chronological ages. Their body weights, heights and arm spans were obtained using standard methods; the corrected body heights of the adolescent idiopathic scoliosis boys were determined using Bjour's equation. The inter-group differences in the anthropometric parameters were analyzed. Multivariate regression analysis was carried out in the adolescent idiopathic scoliosis patients to identify the anthropometric parameters that influence curve severity.

RESULTS

The corrected standing heights and arm spans of male adolescent idiopathic scoliosis patients were similar to those of the matched controls during puberty. However, the body weights of the adolescent idiopathic scoliosis patients who were more than 14 years old were significantly less than those of the control group. The body mass index of the adolescent idiopathic scoliosis patients between the ages of 15 and 17 were also significantly less than those of the control subjects. Moreover, a significantly higher incidence of underweight was found in adolescent idiopathic scoliosis patients (8.6%) than in the controls (3.4%). Upon multivariate regression analysis, body weight and chronological age were identified as independent predictors of curve magnitude in male adolescent idiopathic scoliosis patients. The male adolescent idiopathic scoliosis patients with variable curve patterns exhibited no significant differences in their anthropometric parameters.

CONCLUSIONS

The results showed abnormal pubertal growth in the male adolescent idiopathic scoliosis patients compared with their age- and gender-matched normal controls. Despite similar longitudinal growth, the male patients with adolescent idiopathic scoliosis exhibited significantly lower body weights and a higher incidence of underweight during the later stage of puberty compared with their normal controls. These abnormalities in the pubertal growth of male patients were different from those observed in female patients with adolescent idiopathic scoliosis. Body weight could be an important parameter for further longitudinal studies on the prognostication of curve progression in adolescent idiopathic scoliosis.

Inter-observer and intra-observer reliability of the Risser sign in a metropolitan scoliosis screening program

BACKGROUND

Risser staging is one of several criteria used in scoliosis screening programs. This study aimed to evaluate the reliability of a radiologist's Risser interpretations from a large metropolitan scoliosis-screening program when compared to interpretations of 2 pediatric orthopaedic surgeons and 2 orthopaedic residents.

METHODS

During the 2008 to 2009 school year, 275 students were reviewed as part of a metropolitan scoliosis-screening program. 100 of the radiographs were randomly chosen and de-identified for inclusion. Two attending orthopaedic surgeons and 2 orthopaedic residents independently interpreted the films on 3 occasions and assigned each a Risser stage. Inter- and intra-rater analyses using Kappa statistics were performed to determine the reliability of the Risser stage interpretations between the orthopaedic surgeons and the radiologist as well as the reliability of the interpretations among the individual surgeons.

RESULTS

Inter-rater kappa values for the attending surgeons and the radiologist averaged 0.526. Inter-rater kappa values for the resident surgeons and the radiologist averaged 0.490 and 0.101. There was significant agreement between the attending surgeons on all 3 occasions (κ = 0.764, 0.809, 0.837). The intra-rater reliability among the attending surgeons (κ = 0.988, 0.957) and the resident surgeons (κ = 0.813, 0.495) showed statistical significance (P < 0.0001). Only half of the films had perfect agreement between the radiologist and the surgeons and 28% of the films were interpreted with a difference of 2 or more Risser stages. The radiologist did not interpret any of the films as a Risser 4 or 5 but 21% of the films were interpreted as a 4 or 5 by the orthopaedic surgeons.

CONCLUSIONS

The scoliosis-screening program utilizes a referral pathway based on the radiologist's Risser stage interpretation in conjunction with the Cobb angle. The radiologist and the orthopaedic surgeons demonstrated only moderate agreement in their interpretations of Risser stages, resulting in a possible 21% over-referral rate. This study questions the efficacy of using the Risser stage as part of a large metropolitan scoliosis screening program and warrants further investigation.

Comparison of the Paley method using chronological age with use of skeletal maturity for predicting mature limb length in children

BACKGROUND

Treating patients with congenital or acquired limb-length inequality requires accurate estimations of limb length at skeletal maturity. There is controversy over the best indicator of maturity to be used for limb-length calculations. Paley popularized the multiplier method, in which chronological age is used, which has the virtue of simplicity but does not account for the wide variance in timing of the adolescent growth spurt. The purpose of this study was to determine whether the use of chronological age or the level of skeletal maturity provides more accurate limb-length predictions.

METHODS

We identified patients with limb-length inequality, for whom scanograms had been obtained before and at maturity, and who had had no surgical procedures on their normal lower limb. Skeletal maturity was determined with use of the Greulich and Pyle atlas, Tanner-Whitehouse-3 method, and simplified stages described by Sanders et al. The length of the lower extremity was compared with the ultimate limb length and the actual multiplier (final limb length divided by current limb length) for each point in time. A linear model was used to determine the log-transformed multipliers for the level of skeletal maturity, and Paley's multipliers were used for chronological age. Residual standard errors were determined to compare the results of the methods. We also conducted piecewise linear regression on each of the methods and used the residual standard errors to rank their performance and cross-validated the results.

RESULTS

We identified twenty-four patients (twelve girls and twelve boys) who met the study criteria. Most subjects had had multiple scanograms along with skeletal age radiographs (average, 4.5) at different ages. When all ages are considered, the Paley method had the best overall performance, with residual standard errors that were typically =5 cm. However, the Paley method did not perform best for subjects at stage-2 skeletal maturity or above; in those cases, skeletal-maturity-based predictions had residual standard errors of &lt;2 cm.

CONCLUSIONS

While the Paley method, which is based on chronological age, provides reasonable estimates of ultimate limb length for most patients, use of skeletal-maturity determinations appears to provide better predictions of mature limb length during adolescence.

Predicting growth and curve progression in the individual patient with adolescent idiopathic scoliosis: design of a prospective longitudinal cohort study

BACKGROUND

Scoliosis is present in 3-5% of the children in the adolescent age group, with a higher incidence in females. Treatment of adolescent idiopathic scoliosis is mainly dependent on the progression of the scoliotic curve. There is a close relationship between curve progression and rapid (spinal) growth of the patient during puberty. However, until present time no conclusive method was found for predicting the timing and magnitude of the pubertal growth spurt in total body height, or the curve progression of the idiopathic scoliosis.The goal of this study is to determine the predictive value of several maturity indicators that reflect growth or remaining growth potential, in order to predict timing of the peak growth velocity of total body height in the individual patient with adolescent idiopathic scoliosis. Furthermore, different parameters are evaluated for their correlation with curve progression in the individual scoliosis patient.

METHODS/DESIGN

This prospective, longitudinal cohort study will be incorporated in the usual care of patients with adolescent idiopathic scoliosis. All new patients between 8 and 17 years with adolescent idiopathic scoliosis (Cobb angle >10 degrees) visiting the outpatient clinic of the University Medical Center Groningen are included in this study. Follow up will take place every 6 months. The present study will use a new ultra-low dose X-ray system which can make total body X-rays. Several maturity indicators are evaluated like different body length dimensions, secondary sexual characteristics, skeletal age in hand and wrist, skeletal age in the elbow, the Risser sign, the status of the triradiate cartilage, and EMG ratios of the paraspinal muscle activity. Correlations of all dimensions will be calculated in relationship to the timing of the pubertal growth spurt, and to the progression of the scoliotic curve. An algorithm will be made for the optimal treatment strategy in the individual patient with adolescent idiopathic scoliosis.

DISCUSSION

This study will determine the value of many maturity indicators and will be useful as well for other clinicians treating children with disorders of growth. Since not all clinicians have access to the presented new 3D X-ray system or have the time to make EMG's, for example, all indicators will be correlated to the timing of the peak growth velocity of total body height and curve progression in idiopathic scoliosis. Therefore each clinician can chose which indicators can be used best in their practice.

TRIAL REGISTRATION NUMBER

NTR2048.

The classic: The iliac apophysis: an invaluable sign in the management of scoliosis. 1958

This biographical sketch of Joseph C. Risser Sr. corresponds to the historic text, The Classic: The Iliac Apophysis: An Invaluable Sign in the Management of Scoliosis, available at DOI 10.1007/s11999-009-1096-z.

Correlation and comparison of Risser sign versus bone age determination (TW3) between children with and without scoliosis in Korean population

BACKGROUND

Most studies comparing the Risser staging for skeletal maturity are representing the American or European standards which are not always applicable to Asian population who have relatively less height and body mass. There is no article available that compares the Risser sign and bone age correlation between patients with idiopathic scoliosis and patients without scoliosis.

MATERIALS AND METHODS

To analyze and compare the skeletal age with the Risser sign between scoliosis and non-scoliosis group, a cross-sectional study was done in 418 scoliosis (untreated, bracing or surgically) and 256 non-scoliosis children of Korean origin. Relationship was found in both groups using Pearson correlation test.

RESULTS

In scoliosis group, Pearson correlation exhibited significant correlation (p < 0.01) between Risser sign and chronological age (r2 = 0.791 for girls, 0.787 for boys) and Risser sign and TW3 age (r2 = 0.718 for girls, 0.785 for boys). Non-scoliosis group also showed significant relationship (p < 0.01) between Risser sign and chronological age (r2 = 0.893 for girls, 0.879 for boys) and Risser sign and TW3 age (r2 = 0.913 for girls, 0.895 for boys). Similarly, comparing Cobb angles of each patient according to their Risser staging, exhibited that if scoliosis remains untreated Cobb angle will increase with the increase in their Risser staging (r2 = 0.363 for girls, 0.443 for boys; p < 0.01).

CONCLUSION

Our results showed that chronological age is equally as reliable as skeletal age method to compare with Risser sign, and therefore, we do not mean to imply that only the Risser sign compared with skeletal age should be considered in the decision making in idiopathic as well as non-scoliosis patients of Korean ethnicity. Concomitant indicators such as menarchal period, secondary sex characteristics, and recent growth pattern will likely reinforce our data comparing Risser sign with skeletal age in decision making.

Risser sign inter-rater and intra-rater agreement: is the Risser sign reliable?

BACKGROUND

Studies directly evaluating the reliability of the Risser sign are few in number, possess small sample sizes, and offer conflicting results. This study establishes the reliability of the Risser sign on a large sample size in an effort to provide clarification on the subject.

METHODS

Two years' worth of AP pelvis radiographs from patients age 8-20 were downloaded from our institution's digital imaging system. One hundred of these images were selected for inclusion by an independent reviewer whose goal was to capture a spread of radiographs that included all Risser stages. Risser grading occurred in two rounds. In each round, three examiners randomly reviewed the 100 radiographs on three different occasions. The full AP pelvis radiograph was graded in Round 1 while only the iliac apophysis was visible in Round 2. Kappa coefficients and their confidence bounds are reported to indicate intra- and inter-observer reliability. The contrast between the rates of agreement about Risser stages in Rounds 1 versus 2 was assessed by McNemar's test. The signed-rank test was used to evaluate differences in intra-observer values between rounds.

RESULTS

Round 1 inter-observer kappa was 0.76. Round 2 inter-observer kappa was 0.51. In Round 1, 63 radiographs showed perfect agreement within the same Risser stage for all observations compared to 44 radiographs with perfect agreement within the same Risser stage in Round 2 (p = 0.004). Round 1 intra-observer kappa values were 0.92, 0.86, and 0.88. Round 2 intra-observer kappa values were 0.91, 0.77, and 0.88. Intra-observer value differences between rounds were not significant for two observers (p = 0.074, 0.061) but was significant for the third observer (p = 0.002).

CONCLUSION

The reliability of the Risser sign is acceptable and can be further improved when other markers of skeletal maturity on the pelvis radiograph are used to assist in grading.

Improved accuracy in Risser sign grading with lateral spinal radiography

Development of the ossification of the iliac crest is used to assess the remaining spinal growth. The clinical value of the Risser sign has been questioned because of its inaccuracy in grades 3 and 4. Estimation of the Risser sign based on the lateral spinal radiograph has not been reported. The aim of the study was to evaluate the course of ossification of the iliac apophysis along its full extension and to investigate relevance of the lateral spinal radiograph for more accurate Risser sign grading. Cross sectional analysis of spinal frontal and lateral long cassette standing spinal radiographs of 201 girls aged from 10.2 to 20.0 years were done. On the lateral spinal view, the ossification of the posterior part of the iliac apophysis was quantified at four grades: absent (A), partial (B), complete (C) or fused (D). The position of the posterior superior iliac spine was studied on both views as well as in pelvic specimens. The results showed that the posterior one-third portion of the iliac apophysis was sagittally oriented and obscured on the frontal radiograph by the sacroiliac junction. It could be studied on the lateral radiograph and revealed a different grading of the apophysis excursion in 58 of 201 (29%) patients, comparing to the frontal view. Both advanced or delayed ossification was observed and assessed with Lateral Risser Modifiers. Twenty-five percent of the patients at Risser 0 or 1 or 2 demonstrated a simultaneous ossification of the most anterior and the most posterior part of the iliac crest. The Risser grades of capping or fusion could be more precisely diagnosed using lateral radiograph in complement to the frontal one. The conclusions drawn from this study were: (1) Currently used Risser sign grading does not consider the actual excursion of the iliac apophysis, because one-third of the apophysis cannot be observed on the frontal radiograph. (2) Iliac apophysis full excursion or fusion can be more accurately estimated when the lateral spinal radiograph is analyzed with Lateral Risser Modifiers.

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

The determination of skeletal age is essential in the management of patients with scoliosis. One of the most frequently used techniques to determine skeletal maturity is the method described by Risser. However, repeated X-ray exposure in the follow-up examinations of scoliosis patients may increase the risk of cancer. We compared conventional radiological evaluation of the Risser grade with ultrasound evaluation. For scoliosis patients routine application of ultrasound in the follow-up examinations may significantly reduce radiation exposure. 46 adolescent idiopathic scoliosis patients (median age, 14.5 years) were investigated. Sonographic and radiographic assessment of Risser sign was carried out by two independent senior staff skeletal radiologists. Agreement of Risser Grade between the two diagnostic methods was determined by Kappa statistics. Coefficients <0.21, 0.21-0.40, 0.41-0.60, 0.61-0.80, and >0.80 were rated as poor, fair, moderate, good, and very good agreement. For Risser Grades I-III 100% agreement was found between the two methods. Disagreement between radiographic and sonographic evaluation was found in Risser Grades IV and V. In five patients, X-ray evaluation yielded Risser Grade V while ultrasound showed Risser Grade IV. In one patient, radiographic examination resulted in Risser Grade IV while Grade V was detected in ultrasound. Overall, the Kappa value showed very good agreement between the two diagnostic methods. Our findings suggest that ultrasound can be applied as an alternative method to X-ray evaluation in Risser Grade determination. It should be routinely used in clinical practice to reduce the patients exposure to radiation.

Skeletal age assessment from elbow radiographs. Review of the literature

Skeletal age is important to evaluate remaining growth. In 50% of normal children and adolescents, skeletal age does not differ from chronological age. During puberty, skeletal age is an important tool when performing a lower limb epiphysiodesis or when treating (conservatively or surgically) patients with spinal deformities. Skeletal age alone is not enough and should be assessed together with other clinical and radiological findings such as standing and sitting heights, Risser sign, Tanner stages and annual growth rate. Puberty starts at 11 years of skeletal age and ends at 13 years of skeletal age in girls; in boys, puberty starts two years later (13 years of skeletal age) and then ends at a skeletal age of 15. Most current clinical and radiographic markers do not help paediatric orthopaedic surgeons to clearly distinguish maturity levels prior to Risser I. Sauvegrain et al. developed a method to assess skeletal age by using elbow radiographs (AP and lateral projections). Between 11 and 13 years of skeletal age in girls and between 13 and 15 years of skeletal age in boys, the olecranon apophysis is characterised by a clear morphological development. This method is a reliable tool to assess skeletal age during puberty because significant morphological changes in the elbow happen every six months.

Histologic, risser sign, and digital skeletal age evaluation for residual spine growth potential in Chinese female idiopathic scoliosis

STUDY DESIGN

A prospective study.

OBJECTIVE

To ascertain the correlation between histologic grades (HGs) of vertebral growth plates and Risser grades as well as DSA stages in the Chinese female idiopathic scoliosis (IS) patients; to identify whether digital skeletal age (DSA) is a reliable indicator for accurate evaluation of the spinal residual growth potential.

SUMMARY OF BACKGROUND DATA

DSA is considered one of the more important indicators for representing the peak height velocity (PHV) typically and predicting spinal growth potential. The correlation between HGs of growth plates and DSA stages in IS patients is unclear.

METHODS

Thirty-nine Chinese female patients were available for this study. Superior and inferior growth plates were obtained at each level when anterior approach surgeries were performed. Histologic examinations were conducted after the specimens were processed. Of these patients, 28 cases were evaluated by DSA stages in this study. Correlations between histologic grades, Risser grades, menarchal status, and chronologic age were analyzed in 39 patients. Correlations between histologic grades, DSA, menarchal status, and chronologic age were analyzed in 28 patients.

RESULTS

There was a negative correlation between the following: HGs and Risser grades in 39 patients (r = -0.645, P = 0.000-0.05), HGs and menarchal status in patients in Risser 4 (r = -0.710, P = 0.002-0.05), HGs and DSA stages in 28 cases (r = -0.541, P = 0.003-0.05), and HGs and menarchal status in patients in DSA Stage III (r = -0.591, P = 0.006-0.05). Statistical significance of growth activity of growth plates was found between patients in Risser Grades 0 to 1 and those in Risser Grades 2 to 5 (P = 0.020-0.05) and patients in DSA Stage II and those in DSA Stage III (P = 0.014-0.05).

CONCLUSION

DSA may be a reliable indicator for predicting the spinal residual growth potential in IS patients, but it should be correlated with menarchal status and chronologic ages.

Progression risk of idiopathic juvenile scoliosis during pubertal growth

STUDY DESIGN

A retrospective study investigated the progression risk of juvenile scoliosis until skeletal maturity or spinal fusion.

OBJECTIVES

To define risk factors of curve progression during pubertal growth and analyze the timing of arthrodesis.

SUMMARY OF BACKGROUND DATA

Juvenile scoliosis is characterized by a major, extremely variable progression risk. Peak growth velocity is the most critical period. Curve progression related to growth needs to be analyzed critically for an adequate treatment.

METHODS

A total of 205 patients, including 163 girls and 42 boys, with juvenile scoliosis were reviewed at skeletal maturity. The scoliosis was divided into juvenile I with an onset of 4-7 years (52 patients) and juvenile II with an onset of 8-10 years (153). Standing and sitting height, weight, Tanner signs, skeletal age, and menarche were regularly assessed. Topographies and Cobb angles of primary and secondary curves were referred to the pubertal growth diagram.

RESULTS

Of 205 patients, 99 (48.3%) were operated on. Of 109 curves < or = 20 degrees at onset of puberty, 15.6% progressed > 45 degrees and were fused. Of 56 curves of 21 degrees to 30 degrees, the surgical rate increased to 75.0%. It was 100% for curves > 30 degrees . Curves > 20 degrees, which increased and were operated on, progressed significantly during peak growth velocity (P = 0.0014). Curves that progressed by 6 degrees to 10 degrees/y were fused in 70.9%, curves which increased > 10 degrees/y in 100% of cases (P = 0.0001). This risk was highest for primary thoracic curves: King V, III, and II (P = 0.0001). There was no difference between males and females or juvenile I and II.

CONCLUSIONS

Curve pattern, Cobb angle at onset of puberty, and curve progression velocity are strong predictive factors of curve progression. Juvenile scoliosis > 30 degrees increases rapidly and presents a 100% prognosis for surgery (curve > 40 degrees to 45 degrees ). Anticipation is necessary if the scoliosis progresses during the first year of puberty. The prediction is difficult for curves of 21 degrees to 30 degrees during the first 2 years of puberty. Curve pattern and curve progression velocity are useful to detect which curves are likely to progress. From this retrospective analysis, spinal fusion could have been indicated earlier sometimes. An earlier intervention is probably preferable to obtain better curve reduction on a supple spine, even if a perivertebral fusion is necessary. We use the 3 parameters for operative indications. If an early spinal fusion leads to better curve correction needs to be verified on prospective data.

Comparison of manual and digital measurements in adolescent idiopathic scoliosis

STUDY DESIGN

Comparison of manual and digital measurement of radiographic parameters in patients with adolescent idiopathic scoliosis (AIS).

OBJECTIVE

To assess the reliability of digital measures as compared to manual measures in the evaluation of AIS.

SUMMARY OF BACKGROUND DATA

Radiographic parameters are critical to the evaluation of patients with AIS, and are frequently used to monitor curve progression and guide treatment decisions. The reliability of many of the more common radiographic measures has only recently been elucidated for both manual and digital measures. However, a comparative analysis of manual versus digital measures has been performed only for coronal Cobb angles. The inter-technique reliability of these parameters will have increasing importance as digital radiographic viewing and analysis become commonplace.

METHODS

There were 2 independent, blinded observers that measured 30 complete sets of preoperative (posterior-anterior, lateral, and both side-bending) and postoperative (posterior-anterior and lateral) radiographs on 4 different occasions. For the first 2 iterations, manual measurements were taken using the same pencil and protractor. For the last 2 iterations, measurements of digitized radiographs were taken on a software measurement program (PhDx, Albuquerque, NM). Coronal measures included the main thoracic and thoracolumbar/lumbar standing and side-bending Cobb angles, apical vertebral translation, coronal balance, T1 tilt angle, lowest instrumented vertebrae angle, angulation of the disc inferior to the lowest instrumented vertebrae, apical Nash-Moe vertebral rotation, and Risser grade. Sagittal parameters included T2-T5 and T5-T12 regional thoracic kyphosis, T2-T12 thoracic kyphosis, T10-L2 thoracolumbar junction sagittal curvature, T12-S1 lumbar lordosis, and global sagittal balance. The technique-dependent measurement variability and the inter-technique (manual vs. digital), intraobserver reliability were evaluated for each radiographic parameter (within 3 degrees ).

RESULTS

Digital measurement showed decreased intraobserver variability for many (9 of 15) of the radiographic parameters assessed. Likewise, digital measures indicated good or excellent correlation with the absolute values obtained with manual measurement for many (10 of 15) parameters. All but 1 of those parameters having moderate-to-poor correlation had been previously shown to have poor reliability, regardless of measurement technique. Statistically significant differences between measurement variability were noted for 6 measures, including 2 favoring digital and 4, manual. Significant differences in the absolute values were noted for 5 measures, determined at a difference of 3 degrees . However, the differences in both parameter variability and absolute values tended to be small and of little clinical significance for manual versus digital measurement.

CONCLUSIONS

Digital measurement showed improved measurement precision and good correlation with manual measurements for the majority of AIS parameters. Absolute differences between manual and digital measurements were generally small. Therefore, digital measures are acceptable as a valid technique for scoliosis evaluation. The importance of digital versus manual measurement reliability will increase as digital radiographic viewing becomes more prevalent.

[Skeletal age determination from the elbow during pubertal growth]

The Sauvegrain et al. method of assessing skeletal age from elbow radiographs is useful during the 2 years of the pubertal growth spurt: between 11 and 13 years in girls and between 13 and 15 years in boys. This method uses four ossification centers of the elbow: lateral condyle, trochlea, olecranon apophysis, and proximal radial epiphysis. It is based on a 27-point scoring system. The scores of these structures are summed, a total score is determined, and a graph is then used to determine the skeletal age. This simple, reliable, and reproducible method complements the Greulich and Pyle atlas, which does not allow assessment of skeletal age in 6-month intervals during the phase of accelerating growth velocity. In clinical practice, maturity can best be evaluated by associating skeletal age, annual growth rate, and Tanner stages. Skeletal age assessment from the elbow is useful to plan the timing of epiphysiodesis in limb length inequality or to evaluate the progression risk of idiopathic scoliosis.

Differences in the Risser grading systems in the United States and France

A grading system for ossification of the iliac apophysis (Risser sign) came into use in the mid 1950s in the United States and was adopted sometime later with modifications in France and other European countries. Although called by the same name, these systems have important differences that could lead to different choices of how and when to treat patients with spinal deformity. In a retrospective study, two experienced examiners (FDB and KPV) independently reviewed 301 randomly selected spine radiographs from 167 patients with adolescent idiopathic scoliosis and graded them for bilateral iliac crest apophyseal excursion each using a different system. The two grading systems were compared using percent agreements and kappa statistics. There was good to excellent agreement between the two Risser systems in only 50.8% of the patients. In disagreements regarding 147 of 148 patients, the US Risser grade was higher than the French Risser grade. In 130 of these patients (88.5%) the disagreement was one grade, and in 17 patients (11.5%), it was two grades. Therefore, the French Risser grading system uniformly undervalued the ossification excursion compared with the US Risser grading system. We think that the observed discordance is a source of miscommunication and descriptive confusion in the literature and in patient treatment.

LEVEL OF EVIDENCE

Diagnostic study, Level III-1 (study of nonconsecutive patients--no consistently applied reference gold standard). See the Guidelines for Authors for a complete description of levels of evidence.

Reliability Analysis for Digital Adolescent Idiopathic Scoliosis Measurements

OBJECTIVE

Analysis of adolescent idiopathic scoliosis (AIS) requires a thorough clinical and radiographic evaluation to completely assess the three-dimensional deformity. Recently, these radiographic parameters have been analyzed for reliability and reproducibility following manual measurements; however, most of these parameters have not been analyzed with regard to digital measurements. The purpose of this study is to determine the intra- and interobserver reliability of common scoliosis radiographic parameters using a digital software measurement program.

METHODS

Thirty sets of preoperative (posteroanterior [PA], lateral, and side-bending [SB]) and postoperative (PA and lateral) radiographs were analyzed by three independent observers on two separate occasions using a software measurement program (PhDx, Albuquerque, NM). Coronal measures included main thoracic (MT) and thoracolumbar-lumbar (TL/L) Cobb, SB MT Cobb, MT and TL/L apical vertical translation (AVT), C7 to center sacral vertical line (CSVL), T1 tilt, LIV tilt, disk below lowest instrumented vertebra (LIV), coronal balance, and Risser, whereas sagittal measures included T2-T5, T5-T12, T2-T12, T10-L2, T12-S1, and sagittal balance. Analysis of variance for repeated measures or Cohen three-way kappa correlation coefficient analysis was performed as appropriate to calculate the intra- and interobserver reliability for each parameter.

RESULTS

The majority of the radiographic parameters assessed demonstrated good or excellent intra- and interobserver reliability. The relationship of the LIV to the CSVL (intraobserver kappaa = 0.48-0.78, fair to excellent; interobserver kappaa = 0.34-0.41, fair to poor), interobserver measurement of AVT (rho = 0.49-0.73, low to good), Risser grade (intraobserver rho = 0.41-0.97, low to excellent; interobserver rho = 0.60-0.70, fair to good), intraobserver measurement of the angulation of the disk inferior to the LIV (rho = 0.53-0.88, fair to good), apical Nash-Moe vertebral rotation (intraobserver rho = 0.50-0.85, fair to good; interobserver rho = 0.53-0.59, fair), and especially regional thoracic kyphosis from T2 to T5 (intraobserver rho = 0.22-0.65, poor to fair; interobserver rho = 0.33-0.47, low) demonstrated lesser reliability. In general, preoperative measures demonstrated greater reliability than postoperative measures, and coronal angular measures were more reliable than sagittal measures.

CONCLUSIONS

Most common radiographic parameters for AIS assessment demonstrated good or excellent reliability for digital measurement and can be recommended for routine clinical and academic use. Preoperative assessments and coronal measures may be more reliable than postoperative and sagittal measurements. The reliability of digital measurements will be increasingly important as digital radiographic viewing becomes commonplace.

Reliability analysis for manual adolescent idiopathic scoliosis measurements

STUDY DESIGN

Manual radiographic measurement analysis.

OBJECTIVES

To determine the intraobserver and interobserver reliability of numerous radiographic process measures used in the assessment of adolescent idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

Analysis of scoliosis requires a thorough radiographic evaluation to completely assess the deformity. Numerous radiographic process measures have been studied extensively and used for outcomes assessment and thus become the de facto standard of care. However, many of these measures have not been evaluated to determine the reliability and reproducibility. Validation of radiographic process measures is necessary to compare these measures with patient-focused outcome measures, as well as to permit valid comparison of different surgical techniques.

METHODS

Thirty complete sets of long-cassette scoliosis radiographs (anteroposterior [AP], lateral and side-bending preoperative and AP, and lateral postoperative) were analyzed by three independent experienced observers on two separate occasions. Coronal image measures included the coronal Cobb angles, side-bending Cobb, apical vertebral translation, coronal balance, T1 tilt, lowest instrumented vertebrae (LIV) tilt, angulation of the disc below the LIV, apical vertebral rotation (Nash-Moe),and Risser sign; sagittal measures included T2-T5, T5-T12, T2-T12, T10-L2, T12-S1, and sagittal balance. Intraobserver and interobserver reliability for each measure was then assessed.

RESULTS

The vast majority of the radiographic process measures assessed demonstrated good to excellent or excellent intraobserver and interobserver reliability. However, the angulation of the disc below the LIV demonstrated only fair interobserver reliability for postoperative measurements (rho = 0.59). Likewise, Risser grade measurements reflected good intraobserver (0.81-0.99) but only fair interobserver reliability (0.60-0.70). Apical vertebral rotation assessed by the technique of Nash and Moe produced good intraobserver reliability before surgery (0.74-0.85) but only fair reliability after surgery (0.50-0.85). The interobserver reliability for apical Nash-Moe rotation was fair to poor (0.53-0.59). For T2-T5 regional kyphosis, intraobserver (0.22-0.83) and interobserver (0.33-0.47) reliability was generally poor. Overall, the reliability of postoperative measurements tended to be decreased relative to preoperative values, likely due to instrumentation overlying radiographic landmarks.

CONCLUSIONS

Most of the radiographic process measures evaluated in this study demonstrated good or excellent reliability. The reliability of measuring the angulation of the disc below the LIV, the apical Nash-Moe rotation, and Risser grading was decreased relative to other measures. The reliability of measuring T2-T5 regional kyphosis was disappointing and poor. With regards to the other 13 measures assessed, our findings support the use of these process measures obtained by experienced deformity surgeons via manual measurement for routine clinical and academic purposes.

The rib epiphysis and other growth centers as indicators of the end of spinal growth

STUDY DESIGN

The association of capping and fusion of the iliac apophysis, and closure of the proximal humerus and rib epiphyseal growth plates to the end of spinal growth, was evaluated in a cohort of patients with juvenile and adolescent idiopathic scoliosis.

OBJECTIVES

To determine the association of closure of the proximal rib epiphysis growth plate, the proximal humeral epiphyseal growth plate, and capping (Risser 4), and fusion (Risser 5) of the iliac apophysis to growth cessation in patients with idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

Accurate evaluation of remaining spinal growth is the basis of decision-making in skeletally immature patients with scoliosis. The ossification of the iliac apophysis (Risser sign) has been the main indicator used for making this determination. The accuracy of this sign has been called into question and may be supplemented with data from other growth centers.

METHODS

A total of 101 patients with juvenile or adolescent idiopathic scoliosis undergoing brace treatment were followed for a minimum of 2 years following termination of bracing. Serial height measurements and evaluation of iliac apophysis ossification, proximal humerus, and rib epiphysis growth center closure were performed for each patient.

RESULTS

The iliac apophysis capped (Risser 4) at a mean age of 14.9 years for girls and 16.0 years in boys. Seventy-six of the 101 patients (75.2%) had further growth after Risser 4 status. The mean growth was 1.75 cm in the girls and 2.46 cm in the boys. No growth occurred after iliac apophysis fusion (Risser 5) or closure of either the rib epiphysis or proximal humerus growth plates.

CONCLUSIONS

Capping of the iliac apophysis is not the final indicator for the end of spinal growth. Other growth centers should be evaluated in conjunction with serial height measurements when making decisions on the management of the scoliosis patient.

Relationship of peak height velocity to other maturity indicators in idiopathic scoliosis in girls

BACKGROUND

Our aim was to compare height velocity data, obtained from clinical height measurements, for girls who had idiopathic scoliosis with the data for adolescents who did not have scoliosis. We also compared the growth data with chronological age, menarchal age, and Risser sign in terms of their accuracy in the prediction of growth and progression of the scoliosis.

METHODS

One hundred and twenty of 371 patients in a database of girls managed with a brace for the treatment of idiopathic scoliosis had sufficient height data for us to quantify their growth peak. Height velocity data was generated from standing-height measurements obtained, in a scoliosis clinic, with a minimum six-month interval between measurements, and the timing of peak height velocity was calculated. The age at menarche was recorded from the patients' records. The Risser sign and Cobb angle were determined by a single observer. Progression of the scoliosis was defined as an increase in the Cobb angle of at least 10 degrees, compared with the curve magnitude at the time of the initial evaluation, after a minimum of six months. Progression to a magnitude requiring surgery was defined as progression of at least 10 degrees to a magnitude of 45 degrees or more.

RESULTS

The height velocity plot grouped by peak height velocity showed a high peak and a sharp decline with values similar to those in normal populations. Extrapolating from percentile charts, 90 percent of our patients ceased growing by 3.6 years after peak height velocity. The growth peak was blunted (averaged over too long a period such that the data for the period of most rapid growth was averaged in with that for a period of slower growth) when chronological age, menarchal age, and Risser sign were used to predict growth; this indicated that these maturity scales grouped the patients poorly in terms of growth. The primary curve was progressive in eighty-eight of the 120 patients. Sixty of these patients had a curve of more than 30 degrees at peak height velocity, and in fifty (83 percent) of the sixty the curve progressed to 45 degrees or more. The remaining twenty-eight patients had a curve of 30 degrees or less at peak height velocity, with only one curve (4 percent) progressing to 45 degrees or more. Peak height velocity also grouped patients for maximal progression of the curve more accurately than did the other maturity scales, as most of the curves progressed maximally at peak height velocity. There was a wider spread of timing of maximal progression when chronological age, menarchal age, and Risser sign were used to predict progression.

CONCLUSIONS

Height velocities generated from clinical height measurements for patients with idiopathic scoliosis document the growth peak and predict cessation of growth reliably. Knowing the timing of the growth peak provides valuable information on the likelihood of progression to a magnitude requiring spinal arthrodesis.

Spinal growth and a histologic evaluation of the Risser grade in idiopathic scoliosis

STUDY DESIGN

Thirty-four patients with idiopathic scoliosis who underwent anterior spinal surgery as part of the correction of spinal deformity were studied prospectively. Superior and inferior endplates were harvested and examined histologically for evidence of residual growth activity. This was then correlated with Risser grades, chronologic age, and pubertal status.

OBJECTIVES

To clarify the correlation between Risser grade and vertebral endplate growth potential in patients with idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

The importance of longitudinal spinal growth in patients with idiopathic scoliosis and its correlation with curve progression and the crankshaft phenomenon after posterior fusion are well recognized. The Risser grade, which shows the extent of excursion of the iliac apophysis on serial plain radiographs, is commonly used to estimate residual spinal growth. However, the correlation between the Risser grade and vertebral endplate growth potential in patients with idiopathic scoliosis remains unclear.

METHODS

Superior and inferior endplates were harvested from these patients and examined histologically for evidence of residual growth. This was correlated with Risser grade, chronologic age, and pubertal status.

RESULTS

Risser Grade 5 was found to be the only indicator of cessation of vertebral growth in idiopathic scoliosis. Of the 14 patients with Risser Grade 4, 10 showed significant growth activity in the vertebral endplates. The reliability of Risser Grade 4 increases when combined with chronologic age and time since menarche in female patients.

CONCLUSIONS

The crankshaft phenomenon is reported to occur only in patients with Risser Grade 2 or less, particularly those with open triradiate cartilages. Our findings of significant endplate growth activity, even in patients with Risser Grade 4, make it unlikely that the crankshaft phenomenon is caused purely by longitudinal spinal growth.