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

Differences in spine growth potential for Sanders maturation stages 7A and 7B have implications for treatment of idiopathic scoliosis

PURPOSE

This study aimed to clarify the differences in spine and total body height growth and curve progression between Sanders maturation stage (SMS) 7A and 7B in patients with adolescent idiopathic scoliosis (AIS).

METHODS

This retrospective case-control study involving patients with AIS at SMS 7 evaluated the differential gains in the spine (T1-S1) and total body height and curve progression between SMS 7A and 7B. A validated formula was used to calculate the corrected height, accounting for height loss due to scoliosis. A multivariable non-linear and logistic regression model was applied to assess the distinct growth and curve progression patterns between the SMS 7 subtypes, adjusting for potential confounders.

RESULTS

A total of 231 AIS patients (83% girls, mean age 13.9 ± 1.2 years) were included, with follow-up averaging 3.0 years. Patients at SMS 7A exhibited larger gains in spine height (9.9 mm vs. 6.3 mm) and total body height (19.8 mm vs. 13.4 mm) compared with SMS 7B. These findings remained consistent even after adjustments for curve magnitude. Non-linear regression models showed continued spine and total body height increases plateauing after 2 years, significantly greater in SMS 7A. More SMS 7A patients had curve progression over 10°, with an adjusted odds ratio of 3.31.

CONCLUSION

This study revealed that patients staged SMS 7A exhibited more spine and total body growth and a greater incidence of substantial curve progression than those at 7B. These findings imply that delaying brace discontinuation until reaching 7B could be beneficial, particularly for those with larger curves.

LEVEL OF EVIDENCE

Level III (Case-control study).

Using the Proximal Femur Maturity Index at Brace Initiation for Adolescent Idiopathic Scoliosis Predicts Curve Progression Risk

BACKGROUND

The Proximal Femur Maturity Index (PFMI) can be used to assess skeletal maturity on existing whole-spine radiographs without additional radiation. However, the relationship between the PFMI at the initiation of bracing for adolescent idiopathic scoliosis (AIS) and subsequent curve progression remains unknown. This study aimed to investigate the relationship between the PFMI and curve progression, and the predictability of risks to adulthood curve progression and surgical thresholds based on the PFMI grade at brace initiation.

METHODS

This was a prospective study of 202 patients with AIS who were prescribed underarm bracing according to the Scoliosis Research Society criteria and had good brace-wear compliance. The patients were followed from brace initiation until complete skeletal maturity. Longitudinal data on the coronal Cobb angle and skeletal maturity assessments using Risser staging, Sanders staging, the distal radius and ulna classification, and the PFMI were collected. Each patient was assessed on whether the major curve progressed to ≥40° (adulthood deterioration) and ≥50° (the surgical threshold). Logistic regressions were used to predict probabilities of curve progression to the 2 thresholds, adjusted for factors that were significant in univariate analyses.

RESULTS

The PFMI correlated with the other skeletal maturity indices (r s [Spearman rank correlation] = 0.60 to 0.72, p < 0.001 for all). The pre-brace PFMI grade correlated with progression to ≥40° (r rb [rank-biserial correlation] = -0.30, p < 0.001) and to ≥50° (r rb = -0.20, p = 0.005). Based on regression models (p < 0.001) adjusted for the pre-brace major Cobb angle and curve type, brace initiation at PFMI grades 2 and 3 for a curve of ≥30° had predicted risks of 30% (95% confidence interval [CI], 4% to 55%) and 12% (95% CI, 7% to 17%), respectively, for progression to the surgical threshold. Brace initiation at PFMI grade 5 had 0% progression risk.

CONCLUSIONS

The PFMI can be used for predicting curve progression and prognosticating brace outcomes in AIS. Patients with brace initiation at PFMI grade 4 for a curve of <30° or at grade 5 were unlikely to progress to the adulthood deterioration or surgical threshold. In comparison, skeletally immature patients initiating bracing at a PFMI grade of ≤3 for a major curve of ≥30° had a higher risk of progression despite compliant brace wear.

LEVEL OF EVIDENCE

Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Effectiveness of bracing to achieve curve regression in adolescent idiopathic scoliosis

Aims

To systematically evaluate whether bracing can effectively achieve curve regression in patients with adolescent idiopathic scoliosis (AIS), and to identify any predictors of curve regression after bracing.

Methods

Two independent reviewers performed a comprehensive literature search in PubMed, Ovid, Web of Science, Scopus, and Cochrane Library to obtain all published information about the effectiveness of bracing in achieving curve regression in AIS patients. Search terms included "brace treatment" or "bracing," "idiopathic scoliosis," and "curve regression" or "curve reduction." Inclusion criteria were studies recruiting patients with AIS undergoing brace treatment and one of the study outcomes must be curve regression or reduction, defined as > 5° reduction in coronal Cobb angle of a major curve upon bracing completion. Exclusion criteria were studies including non-AIS patients, studies not reporting p-value or confidence interval, animal studies, case reports, case series, and systematic reviews. The GRADE approach to assessing quality of evidence was used to evaluate each publication.

Results

After abstract and full-text screening, 205 out of 216 articles were excluded. The 11 included studies all reported occurrence of curve regression among AIS patients who were braced. Regression rate ranged from 16.7% to 100%. We found evidence that bracing is effective in achieving curve regression among compliant AIS patients eligible for bracing, i.e. curves of 25° to 40°. A similar effect was also found in patients with major curve sizes ranging from 40° to 60° when combined with scoliosis-specific exercises. There was also evidence showing that a low apical vertebral body height ratio, in-brace correction, smaller pre-brace Cobb angle, and daily pattern of brace-wear compliance predict curve regression after bracing.

Conclusion

Bracing provides a corrective effect on scoliotic curves of AIS patients to achieve curve regression, given there is high compliance rate and the incorporation of exercises.

Is there a skeletal age index that can predict accurate curve progression in adolescent idiopathic scoliosis? A systematic review

BACKGROUND

The diagnosis of adolescent idiopathic scoliosis requires clinical and radiographic evaluation; the management options vary depending on the severity of the curve and potential for progression. Identifying predictors of scoliosis progression is crucial to avoid incorrect management; clinical and radiographic factors have been studied as potential predictors. The present study aims to review the literature on radiological indexes for the peak height velocity or curve acceleration phase to help clinicians manage treatment of patients with adolescent idiopathic scoliosis.

METHODS

This systematic review was carried out in accordance with Preferential Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The search was carried out including only peer-reviewed articles written in English that described the radiological indexes assessing skeletal maturity in patients with adolescent idiopathic scoliosis and evaluated their correlation with curve progression, expressed as peak height velocity and/or curve acceleartion phase.

RESULTS

Thirteen studies were included and showed promising results in terms of reliable radiological indexes. Risser staging gives a general measure of skeletal maturity, but it cannot be used as a primary index for driving the treatment of patients with adolescent idiopathic scoliosis since more reliable indexes are available.

CONCLUSION

Skeletal maturity quantification for adolescent idiopathic scoliosis has the potential to significantly modify disease management. However, idiopathic scoliosis is a complex and multifactorial disease: therefore, it is unlikely that a single index will ever be sufficient to predict its evolution. Therefore, as more adolescent idiopathic scoliosis progression-associated indexes are identified, a collective scientific effort should be made to develop a therapeutic strategy based on reliable and reproducible algorithms.

Reliability of the Risser+ grade for assessment of bone maturity in pediatric scoliosis cases: Investigation using standing and supine whole-spine radiograph

BACKGROUND

Although several radiography-based systems for assessing skeletal maturity are available to clinicians, the classical Risser grading system remains a clinical gold standard. For scoliosis follow-up, a standing whole-spine radiograph is usually used. However, in our clinical practice, we have occasionally encountered cases in which ossification of the iliac crest is seen differently in the standing and supine whole-spine radiography. Here, we aimed to clarify the reliability of the Risser+ grading system for supine versus standing position radiographs.

METHODS

This study recruited patients with all types of scoliosis who had been radiographed in both the standing and supine positions. We retrospectively evaluated the Risser+ grade of standing and supine whole-spine radiographs taken consecutively. Kappa statistics were computed to investigate the agreement between standing and supine Risser+ grades for this study.

RESULTS

We evaluated 111 patients (age: 12.6 ± 2.0; male-to-female = 23:88). The Kappa value for the standing and supine Risser+ grade systems was 0.74. The degree of agreement between the two positions for each Risser+ grade revealed high agreement for grades 0 and 5 in all cases, whereas grades 2 and 3 had low agreement.

CONCLUSIONS

Overall, there was substantial agreement between the Risser+ grades assigned to standing and supine position radiographs. However, disagreement was observed between standing and supine position radiographs assigned Risser+ grades of 2 or 3. Therefore, we have found a wide range in the visibility of iliac apophysis ossification of the iliac depending on the posture, and there are limitations in assessing bone maturity using the Risser+ grade alone. Clinicians should use other evaluation systems, in addition to the Risser+ system, to achieve a more accurate bone maturity assessment, especially for cases with standing position radiographs assigned Risser grades of 2 or 3.

Predicting Progression in Adolescent Idiopathic Scoliosis at the First Visit by Integrating 2D Imaging and 1D Clinical Information

STUDY DESIGN

Retrospective observational study.

OBJECTIVES

The prediction of curve progression in patients with adolescent idiopathic scoliosis (AIS) remains an unresolved area in orthopedic surgery. To make a rapid meaningful prediction, easily accessible multi-dimensional data at the patient's first consultation should be used. Current studies use clinical growth parameters and numerical values extracted from radiographs to compile a predictive model, leaving out the radiographs themselves. Such practice inevitably wastes a lot of information. Thus, this study aims to create a neural network that can predict AIS progression among patients with curves indicated for bracing by integrating both one-dimensional (1D) clinical and two-dimensional (2D) radiological data collected at the patient's first visit in a fully automated manner.

METHODS

513 idiopathic scoliosis patients indicated for and managed with bracing orthosis were recruited. After exclusion, 463 patients were included in deep learning analysis. Processed first-visit growth parameters and posteroanterior radiographs are used as training inputs and the curve progression outcomes obtained in follow ups are used as binary training outputs. The CapsuleNet architecture was modified and trained accordingly to make a prediction.

RESULTS

The final model achieved 90% sensitivity with an overall accuracy of 73.9% in the prediction of AIS in-brace curve progression by using first-visit multi-dimensional data, outperforming conventional convolutional neural networks.

CONCLUSIONS

This first-ever multidimensional-input model shows promise in serving as a screening tool for AIS in-brace curve progression. The incorporation of such a model into routine AIS diagnostic pipeline can assist orthopedics clinicians in personalizing the most appropriate management for each patient.

The Sanders Classification and Obesity: Do Obese Kids With AIS Present With More Advanced Skeletal Maturity?

INTRODUCTION

Obese and overweight (OOW) patients with adolescent idiopathic scoliosis (AIS) have been shown to initially present with a more advanced Risser score compared to normal weight (NW) patients. The Sanders Maturity Scale (SMS) is now more commonly used by surgeons to assist with treatment decisions because it more reliably predicts skeletal maturity. However, the relationship between SMS and obesity has not been described. We hypothesize that in patients with AIS, OOW patients will have a higher SMS score on initial presentation when compared to NW patients.

METHODS

Billing data from 2 different institutions were used to identify patients with AIS presenting to a pediatric orthopaedic spine surgeon for an initial visit between July 2012 and March 2020. We excluded those without height/weight data, spine radiographs, or left-hand radiographs for measuring SMS stage. Body mass index-for-age percentiles were calculated and used to group patients into NW (<85th percentile) or OOW (85th percentile and above) per Centers for Disease Control guidelines. After collecting preliminary data, a power analysis was performed using average SMS scores between NW and OOW patients with an alpha of 0.5, determining a needed sample size of approximately 300 male and 300 female subjects.

RESULTS

Five hundred ninety patients (296 female, 294 male) were identified. The SMS stage at presentation was significantly greater in OOW compared to NW patients for both females (5.9±1.8 vs. 5.2±1.7; P =0.003) and males (4.9±1.9 vs. 4.1±1.8; P =0.002). The major curve magnitude for OOW females was significantly different from NW females (36±16 degrees vs. 30±16 degrees; P =0.004). The major curve magnitude was not different for OOW and NW males ( P =0.3).

CONCLUSION

At initial presentation, OOW patients present at a greater skeletal maturity as measured by the SMS compared with NW patients. OOW female patients present with a greater major curve magnitudes than NW female patients. These results highlight negative implications of the pediatric obesity epidemic as it relates to the AIS population. These findings can be used to counsel families and provide anticipatory guidance for the AIS treatment plan.

LEVEL OF EVIDENCE

Level III-cross-sectional study.

Can the proximal humeral ossification system (PHOS) effectively guide brace weaning in patients with adolescent idiopathic scoliosis?

PURPOSE

The proximal humeral epiphyses can be conveniently viewed in routine spine radiographs. This study aimed to investigate whether the proximal humeral epiphyseal ossification system (PHOS) can be used to determine the timing of brace weaning in adolescent idiopathic scoliosis (AIS), as assessed by the rate of curve progression after brace weaning.

METHODS

A total of 107 patients with AIS who had weaned brace-wear at Risser Stage  ≥  4, no bodily growth and post-menarche  ≥  2 years between 7/2014 and 2/2016 were studied. Increase in major curve Cobb angle > 5° between weaning and 2-year follow-up was considered curve progression. Skeletal maturity was assessed using the PHOS, distal radius and ulna (DRU) classification, Risser and Sanders staging. Curve progression rate per maturity grading at weaning was examined.

RESULTS

After brace-wear weaning, 12.1% of the patients experienced curve progression. Curve progression rate for weaning at PHOS Stage 5 was 0% for curves < 40°, and 20.0% for curves ≥ 40°. No curve progression occurred when weaning at PHOS Stage 5 with radius grade of 10 for curves ≥ 40°. Factors associated with curve progression were: Months post-menarche (p = 0.021), weaning Cobb angle (p = 0.002), curves < 40° versus ≥ 40° (p = 0.009), radius (p = 0.006) and ulna (p = 0.025) grades, and Sanders stages (p = 0.025), but not PHOS stages (p = 0.454).

CONCLUSION

PHOS can be a useful maturity indicator for brace-wear weaning in AIS, with PHOS Stage 5 having no post-weaning curve progression in curves < 40°. For large curves ≥ 40°, PHOS Stage 5 is also effective in indicating the timing of weaning together with radius grade ≥ 10.

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.

Adolescent Idiopathic Scoliosis for Pediatric Providers

Adolescent idiopathic scoliosis occurs in 2% to 3% of the adolescent population, affecting people between ages 10 and 16 years. Scoliosis onset is usually earlier in girls than in boys-generally occurring between ages 10 and 14 years for girls and 12 and 16 years for boys. The cause of idiopathic scoliosis is unknown. It is probably multifactorial. Much of the research on the etiology has focused on connective tissue abnormalities, nutritional deficiency, and genetic factors. [Pediatr Ann. 2022;51(9):e364-e369.].

The Utility of a Novel Proximal Femur Maturity Index for Staging Skeletal Growth in Patients with Idiopathic Scoliosis

BACKGROUND

For growing patients, it is ideal to have a growth plate visible in routine radiographs for skeletal maturity assessment without additional radiation. The proximal femoral epiphyseal ossification is in proximity to the spine; however, whether it can be used for assessing a patient's growth status remains unknown.

METHODS

Two hundred and twenty sets of radiographs of the spine and the left hand and wrist of patients with idiopathic scoliosis were assessed for skeletal maturity and reliability testing. Risser staging, Sanders staging (SS), distal radius and ulna (DRU) classification, the proximal humeral ossification system (PHOS), and the novel proximal femur maturity index (PFMI) were used. The PFMI was newly developed on the basis of the radiographic appearances of the femoral head, greater trochanter, and triradiate cartilage. It consists of 7 grades (0 to 6) associated with increasing skeletal maturity. The PFMI was evaluated through its relationship with pubertal growth (i.e., the rate of changes of standing and sitting body height [BH] and arm span [AS]) and with established skeletal maturity indices. Longitudinal growth data and 780 corresponding spine radiographs were assessed to detect peak growth using receiver operating characteristic (ROC) curve analysis.

RESULTS

The PFMI was found to be correlated with chronological age (τ b = 0.522), growth rates based on standing BH (τ b = -0.303), and AS (τ b = -0.266) (p < 0.001 for all). The largest growth rate occurred at PFMI grade 3, with mean standing BH growth rates (and standard deviations) of 0.79 ± 0.44 cm/month for girls and 1.06 ± 0.67 cm/mo for boys. Growth rates of 0.12 ± 0.23 cm/mo (girls) and 0 ± 0 cm/mo (boys) occurred at PFMI grade 6, indicating growth cessation. Strong correlations were found between PFMI gradings and Risser staging (τ b = 0.743 and 0.774 for girls and boys), Sanders staging (τ b = 0.722 and 0.736, respectively), and radius (τ b = 0.792 and 0.820) and ulnar gradings (τ b = 0.777 and 0.821), and moderate correlations were found with PHOS stages (τ b = 0.613 and 0.675) (p < 0.001 for all). PFMI gradings corresponded to as young as SS1, R4, U1, and PHOS stage 1. Fair to excellent interrater and intrarater reliabilities were observed. PFMI grade 3 was most prevalent and predictive for peak growth based on ROC results.

CONCLUSIONS

The PFMI demonstrated clear pubertal growth phases with satisfactory reliability. Grade 3 indicates peak growth and grade 6 indicates growth cessation.

CLINICAL RELEVANCE

The use of PFMI can benefit patients by avoiding additional radiation in skeletal maturity assessment and can impact current clinical protocol of patient visits. PFMI gradings had strong correlations with SS, DRU gradings, and Risser staging, and they cross-referenced to their established grades at peak growth and growth cessation. PFMI may aid in clinical decision making.

Curve type, flexibility, correction, and rotation are predictors of curve progression in patients with adolescent idiopathic scoliosis undergoing conservative treatment : a systematic review

AIMS

The aim of this study was to review the current evidence surrounding curve type and morphology on curve progression risk in adolescent idiopathic scoliosis (AIS).

METHODS

A comprehensive search was conducted by two independent reviewers on PubMed, Embase, Medline, and Web of Science to obtain all published information on morphological predictors of AIS progression. Search items included 'adolescent idiopathic scoliosis', 'progression', and 'imaging'. The inclusion and exclusion criteria were carefully defined. Risk of bias of studies was assessed with the Quality in Prognostic Studies tool, and level of evidence for each predictor was rated with the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. In all, 6,286 publications were identified with 3,598 being subjected to secondary scrutiny. Ultimately, 26 publications (25 datasets) were included in this review.

RESULTS

For unbraced patients, high and moderate evidence was found for Cobb angle and curve type as predictors, respectively. Initial Cobb angle > 25° and thoracic curves were predictive of curve progression. For braced patients, flexibility < 28% and limited in-brace correction were factors predictive of progression with high and moderate evidence, respectively. Thoracic curves, high apical vertebral rotation, large rib vertebra angle difference, small rib vertebra angle on the convex side, and low pelvic tilt had weak evidence as predictors of curve progression.

CONCLUSION

For curve progression, strong and consistent evidence is found for Cobb angle, curve type, flexibility, and correction rate. Cobb angle > 25° and flexibility < 28% are found to be important thresholds to guide clinical prognostication. Despite the low evidence, apical vertebral rotation, rib morphology, and pelvic tilt may be promising factors. Cite this article: Bone Joint J 2022;104-B(4):424-432.

Supine correction index as a predictor for brace outcome in adolescent idiopathic scoliosis

Aims

The aim of this study was to assess the ability of morphological spinal parameters to predict the outcome of bracing in patients with adolescent idiopathic scoliosis (AIS) and to establish a novel supine correction index (SCI) for guiding bracing treatment.

Methods

Patients with AIS to be treated by bracing were prospectively recruited between December 2016 and 2018, and were followed until brace removal. In all, 207 patients with a mean age at recruitment of 12.8 years (SD 1.2) were enrolled. Cobb angles, supine flexibility, and the rate of in-brace correction were measured and used to predict curve progression at the end of follow-up. The SCI was defined as the ratio between correction rate and flexibility. Receiver operating characteristic (ROC) curve analysis was carried out to assess the optimal thresholds for flexibility, correction rate, and SCI in predicting a higher risk of progression, defined by a change in Cobb angle of ≥ 5° or the need for surgery.

Results

The baseline Cobb angles were similar (p = 0.374) in patients whose curves progressed (32.7° (SD 10.7)) and in those whose curves remained stable (31.4° (SD 6.1)). High supine flexibility (odds ratio (OR) 0.947 (95% CI 0.910 to 0.984); p = 0.006) and correction rate (OR 0.926 (95% CI 0.890 to 0.964); p < 0.001) predicted a lower incidence of progression after adjusting for Cobb angle, Risser sign, curve type, menarche status, distal radius and ulna grading, and brace compliance. ROC curve analysis identified a cut-off of 18.1% for flexibility (sensitivity 0.682, specificity 0.704) and a cut-off of 28.8% for correction rate (sensitivity 0.773, specificity 0.691) in predicting a lower risk of curve progression. A SCI of greater than 1.21 predicted a lower risk of progression (OR 0.4 (95% CI 0.251 to 0.955); sensitivity 0.583, specificity 0.591; p = 0.036).

Conclusion

A higher supine flexibility (18.1%) and correction rate (28.8%), and a SCI of greater than 1.21 predicted a lower risk of progression. These novel parameters can be used as a guide to optimize the outcome of bracing.

Cite this article: Bone Joint J 2022;104-B(4):495–503.