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

Immediate vs Gradual Brace Weaning Protocols in Adolescent Idiopathic Scoliosis: A Randomized Clinical Trial

Importance

Lack of evidence and consensus for brace weaning protocol in adolescent idiopathic scoliosis (AIS) results in clinicians prescribing gradual weaning in the hope of avoiding curve deterioration after weaning. However, gradual weaning contributes to prolonged brace wear, which can affect spinal stiffness and health-related quality of life (HRQoL).

Objective

To determine whether gradual weaning results in better curve magnitude and truncal balance maintenance after brace weaning vs immediate brace removal for patients with AIS.

Design, Setting, and Participants

This was an open-labeled randomized clinical trial commenced in April 2017 with 24-month follow-up completed in January 2023. Outcome assessors were masked to weaning protocol assigned. The study took place at a territory-wide tertiary scoliosis clinic serving the largest number of referrals in the local population. Patients with AIS ready to wean off of brace wear were eligible (402 were screened; 33 were excluded [15 for <18 hours/day of brace-wear compliance before weaning, 11 were treated with Milwaukee brace, and 7 declined to participate]; and 369 were included), and those who were treated with a custom molded thoracolumbosacral orthosis and had reached skeletal maturity were consecutively recruited.

Interventions

Patients were randomized to gradual weaning protocol (n = 176) with an additional 6 months of nighttime wear before completely stopping or immediate weaning protocol (n = 193) with immediate brace removal at recruitment.

Main Outcomes and Measures

Changes in major curve Cobb angle and truncal balance from the time of weaning to 6-month, 12-month, and 24-month follow-up. HRQoL was also assessed using the refined Scoliosis Research Society 22-item and EuroQol 5-dimension questionnaires.

Results

A total of 369 patients (mean [SD] age, 14.9 [1.1] years; 304 [83.4%] girls) were randomized with 284 (77.0%) completing 24-month longitudinal follow-up. Immediate and gradual weaning groups had no significant differences in change of major Cobb angle at postweaning 6-month (difference, -0.6°; 95% CI, -1.4 to 0.2; P = .17), 12-month (difference, -0.3°; 95% CI, -1.2 to 0.6; P = .47), and 24-month (difference, -0.3°; 95% CI, -1.2 to 0.7; P = .60) follow-up. The number of curve progression, nonprogression, and rebound cases were comparable (χ22 = 2.123; P = .35). Postweaning changes in truncal balance and HRQoL demonstrated no significant differences between groups.

Conclusions

Gradual weaning did not demonstrate superiority to immediate weaning with predefined criteria of Cobb angle and truncal balance maintenance and HRQoL after brace weaning. Gradual and immediate weaning achieved very similar maintenance of brace outcomes in AIS. We therefore recommend the consideration of immediate brace weaning, which aims to benefit patients with earlier time for increased exercises and activity level.

Trial Registration

ClinicalTrials.gov Identifier: NCT03329716.

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.

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.

Functional and radiologic outcomes of non-displaced scaphoid waist fractures in adolescents approaching skeletal maturity: Comparison between conservative treatment and percutaneous screw fixation

BACKGROUND

Treatment of scaphoid waist fractures is generally conservative in children but surgical in adults, given the relatively high risk of non-union in adults. In adolescents, the required therapeutic strategy is less well defined. The objective of this study was to compare the radiographic and clinical parameters, and the rate of complications, between non-surgical orthopedic treatment (OT) and surgical treatment (ST) by percutaneous screw fixation of these fractures in adolescents approaching skeletal maturity.

HYPOTHESIS

ST of non-displaced scaphoid waist fractures in adolescents allows radiographic union, a functional result and a complication rate comparable to that of ST.

METHODS

This single-center retrospective study included patients who presented with a non-displaced scaphoid waist fracture, with a chronological age (CA) and a bone age (BA) between 14 and 18 years. Clinical and radiographic parameters and complications were analyzed during the trauma and at one year, including functional scores, between two groups of patients; OT and ST.

RESULTS

Thirty-seven patients had OT (63.8%) and 21 had ST (36.2%). The median CA was 16 years [14.25-16]. The median BA was 16 years [15;17] according to the Greulich and Pyle method and corresponded to R9 [R7-R10] and U7 [U7;U8] according to the Distal Radius and Ulnar (DRU) classification system. All non-unions were found in the OT group (23.4% vs. 0%, p=0.019). The duration of immobilization (8 weeks) and the number of consultations were higher after OT than ST. Functional scores were lower in patients with non-union after OT (p≤0.002) CONCLUSION: OT of scaphoid waist fractures in adolescents results in a higher rate of non-union than ST, similar to the rate found in adults. Findings from this study recommend a surgical approach by percutaneous screw fixation.

LEVEL OF EVIDENCE

III; comparative retrospective study.

Age-of-cessation of lumbar lordosis development as an assessment parameter

BACKGROUND

In managing paediatric spinal deformities, the currently-in-use growth maturity assessment parameters (clinical or radiological) are based mostly on Caucasian populations. They may be adequate for general treatment planning but may not accurately predict the remaining growth potential. Some therapies (e.g. growing rod distractions or growth modulation surgeries) require more accurate predictions of remaining growth potential and race-specific values. Lumbar lordosis (LL) development ceases at spinal bone maturity. The age-of-cessation seems a more accurate predictor of remaining spinal bone growth potential, compared to currently-in-use growth maturity assessment parameters, but is rarely included in the growth maturity assessment parameters.

AIMS AND OBJECTIVES

As a predictor of remaining spinal growth potential, age-of-cessation of LL development (Race-specific of Black populations) was quantified.

MATERIALS AND METHODS

In archival normal lateral lumbosacral radiographs of patients of a tertiary hospital in South-East Nigeria, LL development across five age groups (Birth- 9, 10-15, 16-20, 21-25 and 26-30 years) was quantified with lumbosacral joint angle (LSJA) in 215 (110 males, 105 females), and lumbosacral angle (LSA) in 238 (119 males, 119 females). Data were analysed with IBM SPSS Statistics 23.0 (NY, USA). P ≤ 0.05 was considered statistically significant.

RESULTS

Both LSJA and LSA age groups' mean values progressively increased with age, and plateaued at 21-25 years range, with LSJA mean of 23.4 ± 1.3 years, and LSA mean 23.5 ± 1.3 years; the means difference was insignificant (P = 0.680).

CONCLUSION

With ageing, there is progressive increment, and later, cessation of LL. Age-of-cessation indirectly infers spinal-maturity-age, and could indirectly be an assessment parameter of spinal-maturity-status.

REPRODUCIBILITY OF THE CLASSIFICATION OF PROXIMAL HUMERAL OSSIFICATION IN IDIOPATHIC SCOLIOSIS

ABSTRACT Objective To evaluate the intra- and interobserver reproducibility of the classification of proximal humeral ossification in patients with idiopathic scoliosis. Methods Observational, descriptive, cross-sectional study. Radiographs (anteroposterior) of 29 patients diagnosed with idiopathic scoliosis were chosen and investigated at the Spine Surgery Outpatient Clinic of the Department of Orthopedics and Traumatology of the Hospital Getúlio Vargas, Recife, Pernambuco. These radiographs were evaluated and classified by 9 spinal orthopedic surgeons at two moments, with a minimum interval of 30 days, for analysis of the intraobserver and interobserver reproducibility of the classification of proximal humeral ossification used as a predictor of peak growth velocity. Results Intraobserver reproducibility achieved moderate to substantial concordance with the kappa index. In the analysis of interobserver reproducibility using the Fleiss’ kappa method, a reasonable to moderate concordance was observed, except for in stage 5, in which concordance ranged from substantial to almost perfect. Conclusion In this study, the reproducibility of the Li classification in most of the stages was reasonable to moderate for the interobserver assessment and moderate to substantial for the intraobserver assessment, which differs from the current literature. Level of evidence III; Diagnostic studies – Investigation of a diagnostic test.

Prediction of Final Body Height for Female Patients With Adolescent Idiopathic Scoliosis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To explore the possibility of predicting final body height at maturity based on associating parameters at the time of diagnosing adolescent idiopathic scoliosis (AIS), while examining the effect of curve magnitude and deterioration.

METHODS

A total of 284 female patients with AIS (mean age 12.2 ± 1.1 years, 52.5% premenarchal) were followed till skeletal maturity, indicated by ≥Risser stage 4, static body height and arm span over the past 6 months, and postmenarche 2 years. Standing body height, arm span, menarchal status, Risser staging, distal radius and ulna (DRU) classification, Sanders staging (SS), Cobb angles (major and minor curves), and Lenke curve types at initial presentation were examined. Patients with/without curve deterioration were compared. Multiple linear regression was used for predicting final body height (cm), and remaining height increase (%).

RESULTS

Baseline body height was 152.1 ± 7.1 cm and major curve Cobb angle was 27.1° ± 7.4°, whereas at maturity they were 159.5 ± 5.4 cm and 32.5° ± 9.3°, respectively. For patients presented at Risser stage 0 or 1, radius grade (R) 6, ulnar grade (U) 5, or SS3, those with curve deterioration exhibited greater height increase potential at initial presentation (P < .05) than those without deterioration. No intergroup difference was found for patients presented at ≥Risser 2, R7, U6, SS4. Predictive baseline parameters were age, body height, Cobb angle (major curve), curve type, and DRU grades. Prediction models of final body height (R ² = 0.735, P < .001) and remaining height increase (R ² = 0.742, P < .001) were established.

CONCLUSIONS

Final body height prediction model was derived for female patients with AIS, with baseline body height and ulnar grading having larger impacts than other parameters.

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.

Controversies with nonoperative management for adolescent idiopathic scoliosis: Study from the APSS Scoliosis Focus Group

PURPOSE

To determine consensus among Asia-Pacific surgeons regarding nonoperative management for adolescent idiopathic scoliosis (AIS).

METHODS

An online REDCap questionnaire was circulated to surgeons in the Asia-Pacific region during the period of July 2019 to September 2019 to inquire about various components of nonoperative treatment for AIS. Aspects under study included access to screening, when MRIs were obtained, quality-of-life assessments used, role of scoliosis-specific exercises, bracing criteria, type of brace used, maturity parameters used, brace wear regimen, follow-up criteria, and how braces were weaned. Comparisons were made between middle-high income and low-income countries, and experience with nonoperative treatment.

RESULTS

A total of 103 responses were collected. About half (52.4%) of the responders had scoliosis screening programs and were particularly situated in middle-high income countries. Up to 34% obtained MRIs for all cases, while most would obtain MRIs for neurological problems. The brace criteria were highly variable and was usually based on menarche status (74.7%), age (59%), and Risser staging (92.8%). Up to 52.4% of surgeons elected to brace patients with large curves before offering surgery. Only 28% of responders utilized CAD-CAM techniques for brace fabrication and most (76.8%) still utilized negative molds. There were no standardized criteria for brace weaning.

CONCLUSION

There are highly variable practices related to nonoperative treatment for AIS and may be related to availability of resources in certain countries. Relative consensus was achieved for when MRI should be obtained and an acceptable brace compliance should be more than 16 hours a day.

Relationship between hand and wrist bone age assessment methods

Assessment of skeletal maturity is crucial for managing growth related problems. Tanner and Whitehouse (TW) hand and wrist bone age assessment is an accurate method; however, it is complex and labor-intensive. Several simplified methods derived from the TW method were proposed, and each had its own character. The purpose of this study is to explore the relationship between these methods for accurate usage.Between 2018 and 2019, a cross-sectional study was performed with consecutive left hand and wrist x-rays obtained from a pediatric orthopedic clinic. Bone age assessments included the distal radius and ulna (DRU) classification, Sanders staging (S), thumb ossification composite index (T), and TW method. Somers delta correlation was conducted to determine the interchangeability of these stages. The mean bone age and standard deviation (SD) of each subgrade were compared and analyzed.Totally 103 films (92 girls) were analyzed with mean age of 12.1 years (range: 8.0-17.9 years). The radius (R) stages had good correlation with S, T, and U stages with a very high Somers delta correlation (P < .05). R5 had relatively large SD (1.5) and referred to T2 and T3; R6 and R7 had the smallest SD (0.3) with reference to T4 or S2; R8 referred to T5 or S3, S4, S5; R9 referred to S6 and S7.The internal relationship between the DRU and digital stages system was well proven. We also provided a simple and accurate way to assess the bone age by combination of some subgrades with smaller SD: 10y-proximal thumb covered without sesamoid (T2); 10.5y-sesamoid just appearing (T3); 11y-distal radial physis just covered (medial double joint line, R6); 11.5y-medial capping of distal radial physis (R7); 12y-bilateral capping of distal radial physis (R8) / phalangeal capping without fusion (S3); 12.5y-distal phalangeal physes start to fuse (S4); 13y-distal phalangeal physes fused (S5); 13.5y-proximal phalangeal physes start to fuse (S6); 14.5y-proximal phalangeal physes fused (S7); 15y-distal radial physis almost fused (R10).Level of Evidence: Diagnostic study, level III.

How do we follow-up patients with adolescent idiopathic scoliosis? Recommendations based on a multicenter study on the distal radius and ulna classification

PURPOSE

To determine the capability of the distal radius and ulna (DRU) classification for predicting the scoliosis progression risk within 1 year in patients with adolescent idiopathic scoliosis (AIS) and to develop simple recommendations for follow-up durations.

METHODS

Medical records of patients with AIS at two tertiary scoliosis referral centers were retrospectively reviewed for their DRU classification and major curve Cobb angles. Baseline DRU grades and Cobb angles with subsequent 1-year follow-up curve magnitudes were studied for scoliosis progression, which was defined as exacerbation of the Cobb angle by ≥ 6°. The relationship between DRU classification and scoliosis progression risk within 1 year was investigated. Patients were divided into three groups according to the Cobb angle (10°-19°, 20°-29°, ≥ 30°).

RESULTS

Of the 205 patients with 283 follow-up visits, scoliosis progression occurred in 86 patients (90 follow-up visits). Radius and ulna grades were significantly related to scoliosis progression (p < 0.001). R6, R7, and U5 grades were significantly related to scoliosis progression risk. The curve progression probability increased as the Cobb angle increased. Cobb angles ≥ 30°, with these grades, led to progression in > 80% of patients within 1 year. Curve progression was less likely for grades R9 and U7. Most patients with more mature DRU grades did not experience progression, even with Cobb angles ≥ 30°.

CONCLUSION

With R6, R7, and U5, scoliosis may progress within a short period; therefore, careful follow-up with short intervals within 6 months is necessary. R9 and U7 may allow longer 1-year follow-up intervals due to the lower progression risk.

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.

Reliability Comparison between "Distal Radius and Ulna" and "Simplified Tanner-Whitehouse III" Assessments for Patients with Adolescent Idiopathic Scoliosis

Study Design

This is a retrospective clinical study.

Purpose

In this study, we aim to evaluate the reliability of the distal radius and ulna assessment (DRU) and simplified Tanner-Whitehouse III classification (sTW3) in Japanese patients with adolescent idiopathic scoliosis (AIS).

Overview of Literature

The greatest curvature of a scoliotic spine occurs at peak-height velocity (PHV), which is the time during which an individual’s height increases at the maximum rate. Diagnosing and appropriately treating AIS before PHV is the most effective way in order to prevent unnecessary deterioration of the scoliosis curve. Although it is difficult to detect scoliosis before PHV, DRU and sTW3, which involve evaluations using a left-hand radiograph, have been reported to be effective.

Methods

We retrospectively evaluated 54 hands of 40 girls with AIS who visited Nara Medical University Hospital from 2000 to 2015 using previously collected radiographs. The examiners included a spine surgeon and a pediatric orthopedic surgeon, each with over 10 years of experience. The reliability of the DRU and sTW3 was evaluated using the kappa coefficient.

Results

The left-hand radiographs of 40 female patients with AIS (mean age, 13.9±1.7 years; N=54 hands) were evaluated by two blinded examiners using the sTW3 and DRU methods. The highest inter-observer and intra-observer reliabilities (kappa, 0.64 and 0.62, respectively) for radius evaluation were determined. Radius evaluation by the DRU showed the highest agreement rate and smallest error between the inter- and intra-observer examinations.

Conclusions

The DRU was the most reliable assessment tool, and it has the potential to be useful for precisely determining the stage of skeletal maturity in outpatient clinics.

Utilization of distal radius and ulna classification scheme in predicting growth peak and curve progression in idiopathic scoliosis girls undergoing bracing treatment

PURPOSE

Distal radius and ulna (DRU) classification scheme has been proposed for predicting skeletal maturity in patients with idiopathic scoliosis (IS). However, the utilization of DRU classification scheme in the assessment of growth peak and curve progression in IS was still inconclusive. This study aimed to correlate the distal radius and ulna stages with several indicators for growth potential and to evaluate the predictive value of DRU system for curve progression in braced female IS patients.

METHODS

This was a consecutive longitudinal study including physically immature IS girls receiving standardized bracing treatment and regularly followed up every 3-6 months until brace weaning. The following data of each visit were collected: chronologic age, standing height, Cobb angle, spinal length, Risser sign, digital skeletal age (DSA) scores and DRU scores. The height velocity (HV), spinal growth velocity (SGV) and angle velocity (AV) of each visit were calculated. The correlation among radius stage, ulna stage, Risser sign, height, spinal length, HV, SGV and AV was studied.

RESULTS

Forty braced IS girls with 349 longitudinal whole spine X-rays were reviewed. The average DRU scores at initial visit were R6.5 ± 1.1 and U4.5 ± 1.2 for radius and ulna, respectively. Both the radius stages between R5 and R8 and ulna stages between U3 and U6 indicated high SGV and high HV. The DSA scores were 402.1 ± 48.8 and 430.8 ± 44.4 at R7 and R8, respectively. The AV values were - 5.9 ± 12.4°/y and - 0.4 ± 1.5°/y at R5 and R6, which increased to 5.9 ± 17.3°/y, 3.1 ± 15.7°/y and 4.2 ± 12.2°/y at R7, R8 and R9, respectively. The DSA scores were 387.3 ± 65.7 for U5 and 432.9 ± 48.5 for U6, respectively. The AV values were - 3.1 ± 0.3°/y at U3, - 1.7 ± 9.3°/y at U4, 2.3 ± 16.1°/y at U5, 5.4 ± 15.5°/y at U6 and 4.4 ± 12.9°/y at U7.

CONCLUSIONS

Both distal radius and ulna scores correlate with the longitudinal growth potential, and thus, the DRU scoring scheme is an alternative predictor for growth potential and curve progression in girls with IS. These slides can be retrieved under Electronic Supplementary Material.

When Should We Wean Bracing for Adolescent Idiopathic Scoliosis?

BACKGROUND

Current brace weaning criteria for adolescents with idiopathic scoliosis (AIS) are not well defined. Risser Stage 4, ≥ 2 years since the onset of menarche, and no further increase in body height over 6 months are considered justifications for stopping bracing. However, despite adherence to such standards, curve progression still occurs in some patients, and so better criteria for brace discontinuation are needed.

QUESTIONS/PURPOSES

(1) Is no change in height measurements over 6 months and Risser Stage 4 sufficient for initiating brace weaning? (2) What is the association between larger curves (45°) at brace weaning and the progression risk? (3) Are a more advanced Risser stage, Sanders stage, or distal radius and ulna classification associated with a decreased risk of curve progression? (4) When should we wean patients with AIS off bracing to reduce the time for brace wear while limiting the risk of postweaning curve progression?

METHODS

All AIS patients who were weaned off their braces from June 2014 to March 2016 were prospectively recruited and followed up for at least 2 years after weaning. A total of 144 patients were recruited with mean followup of 36 ± 21 months. No patients were lost to followup. Patients were referred for brace weaning based on the following criteria: they were Risser Stage 4, did not grow in height in the past 6 months of followup, and were at least 2 years postmenarche. Skeletal maturity was assessed with Risser staging, Sanders staging, and the distal radius and ulna classification. Curve progression was determined as any > 5° increase in the Cobb angle between two measurements from any subsequent six monthly followup visits. All radiographic measurements were performed by spine surgeons independently as part of their routine consultations and without knowledge of this study. Statistical analyses included an intergroup comparison of patients with and without curve progression, binomial stepwise logistic regression analysis, odds ratios (ORs) with their 95% confidence intervals (CIs), and a risk-ratio calculation. A reasonable protective maturity stage would generate an OR < 1.

RESULTS

Among patients braced until they had no change in height for 6 months, were 2 years postmenarche for girls, and Risser Stage 4, 29% experienced curve progression after brace weaning. Large curves (≥ 45°) were associated with greater curve progression (OR, 5.0; 95% CI, 1.7-14.8; p = 0.002) as an independent risk factor. Patients weaned at Sanders Stage 7 (OR, 4.7; 95% CI, 2.1-10.7; p < 0.001), radius Grade 9 (OR, 3.9; 95% CI, 1.75-8.51; p = 0.001), and ulna Grade 7 (OR, 3.1; 95% CI, 1.27-7.38; p = 0.013) were more likely to experience curve progression. The earliest maturity indices with a reasonable protective association were Sanders Stage 8 (OR, 0.21; 95% CI, 0.09-0.48; p < 0.001), and radius Grade 10 (OR, 0.42; 95% CI, 0.19-0.97; p = 0.042) with ulna Grade 9 (no patients with curve progression).

CONCLUSION

Brace weaning indications using Risser staging are inadequate. Curve progression is expected in patients with large curves, irrespective of maturity status. Bone age measurement by either Sanders staging or the distal radius and ulna classification provides clearer guidelines for brace weaning, resulting in the least postweaning curve progression. Weaning in patients with Sanders Stage 8 and radius Grade 10/ulna Grade 9 provides the earliest and most protective timepoints for initiating brace weaning.

LEVEL OF EVIDENCE

Level II, prognostic study.

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.

Rod Lengthening With the Magnetically Controlled Growing Rod: Factors Influencing Rod Slippage and Reduced Gains During Distractions

STUDY DESIGN

Prospective study.

OBJECTIVE

To identify the factors that are associated with rod slippage and to study the pattern of achieved length gain with a standard distraction methodology.

SUMMARY OF BACKGROUND DATA

Ability to achieve successful magnetically controlled growing rod (MCGR) distraction is crucial for gradual spine lengthening. Rod slippage has been described as a failure of internal magnet rotation leading to a slippage and an inability to distract the rod. However, its onset, significance, and risk factors are currently unknown. In addition, how this phenomenon pertains to actual distracted lengths is also unknown.

METHODS

A total of 22 patients with MCGR and at least six distraction episodes were prospectively studied. Patients with rod slippage occurring less than six distraction episodes were considered early rod slippage whereas those with more than six episodes or have yet to slip were grouped as late rod slippage. The association of parameters including body habitus, maturity status, age of implantation, total number of distractions, months of distraction from initial implantation, initial and postoperative Cobb angle, T1-T12, T1-S1, T5-T12 kyphosis, curve flexibility, instrumented length, and distance between magnets in dual rods and between the magnets and apex of the curve with early or late onset of rod slippage were studied. Differences between expected and achieved distraction lengths were assessed with reference to rod slippage episodes and rod exchanges to determine any patterns of diminishing returns.

RESULTS

Patients had mean age of 7.1 years at diagnosis with mean follow-up of 49.8 months. A mean 32.4 distractions were performed per patient. Early rod slippage occurred in 14 patients and late rod slippage occurred in eight patients. Increased height, weight, body mass index, older age, increased T1-12 and T1-S1 lengths, and less distance between magnets were significantly associated with early rod slippage. Expected distraction lengths did not translate to achieve distraction lengths and reduced gains were only observed after achieving one-third of the allowable distracted length in the MCGR. Length gains return to baseline after rod exchange.

CONCLUSION

This is the first study to specifically analyze the impact of rod slippage on distraction lengths and the risk factors associated with its onset and frequency. Increased body habitus and reduced distance between internal magnets significantly influenced rod slippage events. Diminishing returns in distracted length gains were only observed after a period of usage.

LEVEL OF EVIDENCE

3.

Curve Progression in Adolescent Idiopathic Scoliosis Does Not Match Skeletal Growth

BACKGROUND

Determining the peak growth velocity of a patient with adolescent idiopathic scoliosis (AIS) is important for timely treatment to prevent curve progression. It is important to be able to predict when the curve-progression risk is greatest to maximize the benefits of any intervention for AIS. The distal radius and ulna (DRU) classification has been shown to accurately predict skeletal growth. However, its utility in predicting curve progression and the rate of progression in AIS is unknown.

QUESTIONS/PURPOSES

(1) What is the relationship between radius and ulna grades to growth rate (body height and arm span) and curve progression rate? (2) When does peak curve progression occur in relation to peak growth rate as measured by months and by DRU grades? (3) How many months and how many DRU grades elapse between peak curve progression and plateau?

METHODS

This was a retrospective analysis of a longitudinally maintained dataset of growth and Cobb angle data of patients with AIS who presented with Risser Stages 0 to 3 and were followed to maturity at Risser Stage 5 at a single institute with territory-wide school screening service. From June 2014 to March 2016, a total of 513 patients with AIS fulfilled study inclusion criteria. Of these, 195 were treated with bracing at the initial presentation and were excluded. A total of 318 patients with AIS (74% girls) with a mean age of 12 ± 1.5 years were studied. For analysis, only data from initial presentation to commencement of intervention were recorded. Data for patients during the period of bracing or after surgery were not used for analysis to eliminate potential interventional confounders. Of these 318 patients, 192 were observed, 119 were braced, and seven underwent surgery. Therefore 192 patients (60.4%) who were observed were followed up until skeletal maturity at Risser Stage 5; no patients were lost to followup. The mean curve magnitude at baseline was 21.6 ± 4.8. Mean followup before commencing intervention or skeletal maturity was 4.3 ± 2.3 years. Standing body height, arm span, curve magnitude, Risser stage, and DRU classification were studied. A subgroup analysis of 83 patients inclusive of acceleration, peak, and deceleration progression phases for growth and curve progression was studied to determine any time lag between growth and curve progression. Results were described in mean ± SD.

RESULTS

There was positive correlation between growth rate and curve progression rate for body height (r = 0.26; p < 0.001) and arm span (r = 0.26; p < 0.001). Peak growth for body height occurred at radius grade (R) 6 (0.56 ± 0.29 cm/month) and ulna grade (U) 4 (0.65 ± 0.31 cm/month); peak change in arm span occurred at R5 (0.67 ± 0.33 cm/month) and U3 (0.67 ± 0.22 cm/month); and peak curve progression matched with R7 (0.80 ± 0.89 cm/month) and U5 (0.84 ± 0.78 cm/month). Subgroup analysis confirmed that peak curve progression lagged behind peak growth rate by approximately 7 months or one DRU grade. The mean time elapsed between the peak curve progression rate and the plateau phase at R9 U7 was approximately 16 months, corresponding to two DRU grades.

CONCLUSIONS

By using a standard skeletal maturity parameter in the DRU classification, this study showed that the maximal curve progression occurs after the peak growth spurt, suggesting that the curve should be monitored closely even after peak growth. In addition, the period of potential curve continuing progression extends nearly 1.5 years beyond the peak growth phase until skeletal maturity. Future studies may evaluate whether by observing the trend of growth and curve progression rates, we can improve the outcomes of interventions like bracing for AIS.

LEVEL OF EVIDENCE

Level II, prognostic study.

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 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.