Initial Cobb angle reduction velocity following bracing as a new predictor for curve progression in adolescent idiopathic scoliosis

Factors Influencing Optimal Bracing Compliance in Adolescent Idiopathic Scoliosis: A Single-center Prospective Cohort Study

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To identify factors contributing to optimal bracing compliance in adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Poor brace compliance is a key factor affecting brace treatment success in AIS. Predictive factors influencing optimal brace compliance to achieve brace treatment success remain unknown.

MATERIALS AND METHODS

This study included AIS patients aged 10 to 15, with a Cobb angle of 20° to 40°. Demographics data, radiographic assessments, and patient-reported outcomes (including the SRS-22r patient questionnaire) were collected. Brace compliance was monitored using in-brace thermometers, defining optimal bracing time as >18 h/d. Multivariable logistic regression analysis was used to identify predictors of optimal bracing time from the demographic and patient-reported outcomes score before bracing.

RESULTS

Among 122 patients, 59.0% achieved optimal bracing time by six months. The achieved group indicated higher scores in the satisfaction domain before bracing (3.3±0.7 vs. 3.1±0.6; P =0.034). Multivariable logistic regression analysis demonstrated that the satisfaction domain before bracing was an independent factor associated with the achievement of the optimal bracing time [OR 1.97 (95% CI: 1.00-3.89), P =0.049]. The model with bracing at one-month follow-up also demonstrated the bracing at 1 month was a significant factor [OR 1.52 (95% CI: 1.30-1.79), P <0.001].

CONCLUSIONS

Optimal bracing compliance in AIS is significantly influenced by prebracing satisfaction and brace compliance at earlier time points. These findings highlight the need to address psychological factors and early compliance in AIS bracing treatment. SRS-22r can be useful to identify the need for psychological support.

Predictors of Clinically Meaningful Results of Bracing in a Large Cohort of Adolescents with Idiopathic Scoliosis Reaching the End of Conservative Treatment

BACKGROUND

We need good outcome predictors to maximize the treatment efficiency of adolescents with idiopathic scoliosis (AIS). The in-brace correction has shown an important predictive effect on brace failure, while the influence of other variables is still debated. We aimed to identify new outcome predictors from a big prospective database of AIS.

METHODS

Design: Retrospective analysis of prospectively collected data.

INCLUSION CRITERIA

AIS between 21 and 45°, Risser 0-2, brace prescription during the observation, treatment conclusion. All of the participants followed a personalized conservative approach according to the SOSORT Guidelines.

OUTCOMES

End of growth below 30°-40°-50°. The regression model included age, BMI, Cobb angle, ATR, TRACE score, real brace wear (RBW), and in-brace correction (IBC).

RESULTS

A total of 1050 patients, 84% females, ages 12.1 ± 1.1, 28.2 ± 7.9° Cobb. IBC increased by 30%, 24%, and 23% the odds of ending treatment below 30°, 40°, and 50°, respectively. The OR did not change after the covariate adjustment. Cobb angle and ATR at the start also showed a predictive effect.

CONCLUSIONS

The systematic evaluation of IBC in clinics is useful for individuating the patient response to brace treatment more accurately, even in relation to the Cobb angle and ATR degrees at the start. Further studies are needed to increase the knowledge on predictors of AIS treatment results.

Outcome of Conservative Therapy of Adolescent Idiopathic Scoliosis (AIS) with Chêneau-Brace

Chêneau-brace (C-Brace) is a potential tool for the treatment of adolescent idiopathic scoliosis (AIS) with a Cobb angle between 20° and 45° for the primary curve. The aim of the present study was (1) to estimate study cohorts with C-brace therapy success and therapy failure and (2) to analyze possible factors that influence the therapy outcome. Seventy-eight patients with AIS were assessed before the initiation of C-brace treatment. Each patient underwent radiography examinations before the brace, in-brace, and at the therapy end. Cobb angle was considered as increased when the value at the end of therapy was increased more than 5° (Δ > 5°), unchanged—when the value was unchanged within ± 5° and decreased- when the value was decreased more than 5° (Δ < −5°). The study cohort was stratified due to curve topography in the thoracic, thoracolumbar, and lumbar scoliosis groups. Global analysis revealed no statistically significant modification of the Cobb angle (Cobb angle pre-brace vs. Cobb angle post-brace: 30.8° ± 8.2 vs. 29.3° ± 15.2, p = 0.26). However, at the end of C-brace therapy, the primary Cobb angle was decreased by more than 5° in 27 patients (35%), unchanged (Δ within the range of ±5°) in 36 patients (46%), and increased more than 5° in 15 patients (19%). Sub-group analysis due to curve topography and skeletal maturity has shown higher rates of brace therapy failure in thoracic curves and in younger patients (Risser grade 0). Patients with higher Cobb angle correction with C-brace had lower rates of therapy failure. The C-brace can be useful for the prevention of scoliotic curve progression in patients with AIS. However, many factors influence the therapy effect.

Bracing for juvenile idiopathic scoliosis: retrospective review from bracing to skeletal maturity

BACKGROUND

Juvenile idiopathic scoliosis (JIS) outcomes with brace treatment are limited with poorly described bracing protocols. Between 49 and 100% of children with JIS will progress to surgery, however, young age, long follow-up, and varying treatment methods make studying this population difficult. The purpose of this study is to report the outcomes of bracing in JIS treated with a Boston brace™ and identify risk factors for progression and surgical intervention.

METHODS

This is a single-center retrospective review of 175 patients with JIS who initiated brace treatment between the age of 4 and 9 years. A cohort of 140 children reached skeletal maturity; 91 children had surgery or at least 2 year follow-up after brace completion. Standard in-brace protocol for scoliosis 320° was a Boston brace for 18-20 h/day after MRI (n = 82). Family history, MRI abnormalities, comorbidities, curve type, curve magnitude, bracing duration, number of braces, compliance by report, and surgical interventions were recorded.

RESULTS

Children were average 7.9 years old (range 4.1-9.8) at the initiation of bracing. The Boston brace™ was prescribed in 82 patients and nine used night bending brace. Mid-thoracic curves (53%) was the most frequent deformity. Maximum curve at presentation was on average 30 ± 9 degrees, in-brace curve angle was 16 ± 8 degrees, and in-brace correction was 58 ± 24 percent. Patients were braced an average of 4.6 ± 1.9 years. 61/91 (67%) went on to posterior spinal fusion at 13.3 ± 2.1 (range 9.3-20.9) years and curve magnitude of 61 ± 12 degrees. Of those that underwent surgery, 49/55 (86%) progressed > 10°, 6/55 (11%) stabilized within 10°, and 0/55 (0%) improved > 10° with brace wear. No children underwent growth-friendly posterior instrumentation. Of the 28 who did not have surgical correction, 3 (11%) progressed > 10°, 13/28 (46%) stabilized within 10°, and 12/28 (43%) improved > 10° with brace wear.

CONCLUSIONS

This large series of JIS patients with bracing followed to skeletal maturity with long-term follow-up. Surgery was avoided in 33% of children with minimal to no progression, and no child underwent posterior growth-friendly constructs. Risk factors of needing surgery were noncompliance and larger curves at presentation.

Coronal deformity angular ratio as a predictive factor for in-brace curve correction and long-term outcome of brace treatment in adolescents with idiopathic scoliosis

PURPOSE

To investigate the relationship between coronal deformity angular ratio (C-DAR) and in-brace correction (IBC) and their role in predicting the long-term bracing outcome in adolescents with idiopathic scoliosis (AIS).

METHODS

In this retrospective multicenter study, the patient's sex, age, primary curve Cobb angle (at initiation of brace treatment, best in-brace, before spinal fusion, and final follow-up), curve pattern, duration of brace treatment, brace type, and C-DAR at initiation of bracing were recorded. The C-DAR values were classified as < 5, 5 ≤ to ≤ 6, and > 6. The IBC values were classified as ≥ 50%, 40% ≤ to ≤ 49%, and < 40%. We classified the patients into two groups of success and failure according to the Cobb angle at the final follow-up.

RESULTS

A total of 164 patients (25 boys and 119 girls) were included. Bracing was successful in 60.4% of them. There was a significant association between C-DAR and bracing outcome (p < 0.0001). 63.9% of the patients with C-DAR < 5 had an IBC ≥ 50%. However, when C-DAR was 5 ≤ to ≤ 6 and > 6, 29.2% and 16.9% of the patients had an IBC of ≥ 50%, respectively. For patients with IBC ≥ 50%, the success rate of bracing was 89.2%. Results of logistic regression analysis revealed that the strongest predictor for brace treatment outcome was the C-DAR, with an odds ratio of 2.11.

CONCLUSION

C-DAR may be used as a predictive factor for the long-term outcome of brace treatment in AIS.

LEVEL OF EVIDENCE

IV.

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.

Initial In-Brace Correction: Can the Evaluation of Cobb Angle Be the Only Parameter Predictive of the Outcome of Brace Treatment in Patients with Adolescent Idiopathic Scoliosis?

Background: Patients with a better initial in-brace correction could show a higher probability of a successful outcome. However, no one has investigated whether parameters can affect the outcomes. The aim of this retrospective study was to evaluate if the initial correction rate (ICR) could be predictive of the bracing outcome and to determine the role of some mechanical and biological parameters in ICR. Methods: The study population comprised 449 patients who met the inclusion criteria. Curve correction > 10° Cobb defines brace treatment success. Success and failure groups were compared in terms of the Risser sign, initial Cobb angle, initial Perdriolle value and ICR. Results: ICR significantly correlates with initial Perdriolle. The success group had a significantly lower value of Pedriolle and initial Cobb angles, Risser sign and ICR than the failure group. The ICR and lower Risser were significantly associated with the brace treatment outcome. This seems particularly suitable for positivity prediction (Predicting value VP+: 87%). Conclusions: This study confirms that immediate in-brace correction can foretell the brace treatment outcome. Patients with a low Risser sign and a high rate of in-brace correction showed a bracing success of 87%. A correlation between rotation and in-brace correction confirms that rotation is among the parameters that influence the deformed spine reaction to corrective actions the most.

Network meta-analysis of short-term effects of different strategies in the conservative treatment of AIS

PURPOSE

To evaluate the short-term effects of different conservative treatments on in adolescent idiopathic scoliosis.

METHODS

By searching the relevant literature of adolescent idiopathic scoliosis, the curative effects of the three regimens of bracing therapy combined with scoliosis-specific exercises, simple treatment with brace and simple scoliosis-specific exercises were compared. Review manager 5.3, Stata MP16 and Network software packages were used for Reticular Meta-analysis of Cobb's angles before and after treatment.

RESULTS

A total of 364 patients were included in four clinical studies. Reticular meta-analysis showed that the short-term effect of bracing treatment combined with scoliosis-specific exercises was better than that of treatment with brace and scoliosis-specific exercises, with effects of 2.71(95% CI 0.83-4.58) and 3.67(95% CI 1.21-6.14), respectively. There was no statistical difference between simple bracing therapy and scoliosis-specific exercises.

CONCLUSION

Among the three common conservative treatments of adolescent idiopathic scoliosis, the short-term effect of bracing treatment combined with scoliosis-specific exercises is better than that of bracing treatment or scoliosis-specific exercises.

Brace Effectiveness Is Related to 3-Dimensional Plane Parameters in Patients with Adolescent Idiopathic Scoliosis

BACKGROUND

Although scoliosis is a 3-dimensional (3D) deformity, little research has been performed on the use of 3D imaging in brace curve correction. The purpose of the present study was to determine the effect of axial-plane parameters on the outcomes of bracing with a thoracolumbosacral orthosis for adolescent idiopathic scoliosis.

METHODS

This prospective longitudinal cohort study included patients with adolescent idiopathic scoliosis who fulfilled the criteria for bracing according to the Scoliosis Research Society, and was conducted from the time the patient began wearing the brace through a minimum follow-up of 2 years or until a surgical procedure was performed. Radiographs made with use of an EOS Imaging System were used to reconstruct 3D images of the spine at the pre-brace, immediate in-brace, 1-year in-brace, and latest follow-up out-of-brace stages. Univariate and multiple linear regressions were performed to determine the association between axial rotation correction and curve progression at the time of the latest follow-up. Logistic regressions were performed to model the probability of risk of progression.

RESULTS

Fifty-three patients were enrolled, and 46 patients were included in the analysis. At the time of the latest follow-up, 30 patients did not experience curve progression and 16 patients had curve progression. There was no difference in baseline demographic characteristics between groups. For the transverse-plane parameters, there was a significant difference between non-progression and progression groups in pre-brace apical vertebral rotation (4.5° ± 11.2° compared with -2.4° ± 9.8°, respectively; p = 0.044) and in 1-year in-brace apical vertebral rotation correction velocity (2.0° ± 5.0°/year compared with -1.7° ± 4.4°/year, respectively; p = 0.016). Logistic regression analysis showed that pre-brace apical vertebral rotation (odds ratio, 1.063; 95% confidence interval, 1.000 to 1.131; p = 0.049) and 1-year in-brace apical vertebral rotation correction velocity (odds ratio, 1.19; 95% confidence interval, 1.021 to 1.38; p = 0.026) were associated with an increased risk of curve progression. There was no difference in Scoliosis Research Society 22-Item scores between patients who experienced curve progression and those who did not.

CONCLUSIONS

In this prospective study, we demonstrated that axial-plane parameters and the correction of these parameters during bracing are related to the successful use of the brace.

LEVEL OF EVIDENCE

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

Predictors for long-term curve progression after Boston brace treatment of idiopathic scoliosis

BACKGROUND

Identifying factors that predict successful bracing in patients with idiopathic scoliosis may help planning treatment.

AIM

To assess predictors for long-term curve progression and health-related quality of life after Boston brace treatment.

DESIGN

Observational retrospective cohort study with analysis of brace treated patients followed from start until at least 10 years after treatment.

SETTING

Patients recruited from the country's entire population consecutively treated at the National Hospital.

POPULATION

365 patients (339 girls/26 boys) with idiopathic scoliosis. Mean (SD) chronological age/bone age at start bracing was 13.2 (1.9)/12.6 (1.9) years. The primary major curve measured 33.2 (7.4°), and the major levels were thoracic (N.=248), thoracolumbar (N.=78) and lumbar (N.=39). Mean bracing time was 2.8 (1.5) years. Long-term follow-up was in average 23.3 (4.1) years after weaning with a mean major curve of 33.0 (13.1°). Successful treatment was defined as a stable primary curve with progression ≤5°, and secondary the SRS-22 questionnaire assessed quality of life.

METHODS

We applied linear or logistic regression with backward elimination. Internal validation was assessed by bootstrapping. Twelve variables were included in the prediction models: age, bone age, scoliosis in close family, major curve size, level, shape, flexibility and in-brace redressement, compliance, curve magnitude after 1 year, treatment time and quality of life (SRS-22).

RESULTS

290 patients (79%) had rated good compliance using the brace >20 hours daily. Treatment failure was observed in 65 patients (18%), and 27 of them were operated. The best baseline predictors were age and brace redressement. During treatment compliance, major curve after 1 year, and treatment time were the best predictors, while thoracic major curve, curve size at start bracing and scoliosis in close family also contributed to the final model. The model's ability to predict quality of life was low.

CONCLUSIONS

The best predictors for a long-term success were good redressement and compliance, unchanged or reduced major curve after one year and short treatment time.

CLINICAL REHABILITATION IMPACT

Predictors at baseline and during early treatment can help identifying patients who benefit from bracing.

Bracing In The Treatment Of Adolescent Idiopathic Scoliosis: Evidence To Date

Brace effectiveness for adolescent idiopathic scoliosis was controversial until recent studies provided high quality of evidence that bracing can decrease likelihood of progression and need for operative treatment. Very low evidence exists regarding bracing over 40^ο and adult degenerative scoliosis. Initial in-brace correction and compliance seem to be the most important predictive factors for successful treatment outcome. However, the amount of correction and adherence to wearing hours have not been established yet. Moderate evidence suggests that thoracic and double curves, and curves over 30^ο at an early growth stage have more risk for failure. High and low body mass index scores are also associated with low successful rates. CAD/CAM braces have shown better initial correction and are more comfortable than conventional plaster cast braces. For a curve at high risk of progression, rigid and day-time braces are significantly more effective than soft or night-time braces. No safe conclusion on effectiveness can be drawn while comparing symmetrical and asymmetrical brace designs. The addition of physiotherapeutic scoliosis-specific exercises in brace treatment can provide better outcomes and is recommended, when possible. Despite the growing evidence for brace effectiveness, there is still an imperative need for future high methodological quality studies to be conducted.

Vertebra-disc ratio as a new predictor for curve progression in early thoracic AIS with bracing treatment

OBJECTIVES

Previous studies have reported various predictors for curve progression in braced adolescent idiopathic scoliosis (AIS) patients. However, the reported predictors might be insufficient for patients with early AIS. The aim was to investigate whether the initial vertebra-disc ratio (VDR) could serve as an effective predictor for curve progression in early thoracic AIS (premenarchal and Risser 0) undergoing brace treatment.

PATIENTS AND METHODS

This study reviewed a consecutive series of early thoracic AIS girls with thoracic curve. All patients had accepted brace treatment and had regular follow-up. According to the bracing outcomes, patients were divided into two groups: Group P (progressed, curve progressed over six degrees or indicated for surgery) and Group NP (non-progressed).

RESULTS

Totally 203 girls were included. There were 73 and 130 patients in Groups P and NP, respectively. The patients in Group P had greater initial VDR (1.9 ± 0.5 vs. 0.8 ± 0.4, P < 0.01) than Group NP. During the follow-up, it showed continuous higher values in Group P than Group NP. The logistic regression analysis revealed that initial VDR had an effective value for predicting curve progression in the braced early AIS girls. The ideal cut-off point of initial VDR was 1.5 for the prediction of curve progression.

CONCLUSION

The initial VDR could serve as an effective predictor for curve progression in braced early AIS girls. Evaluation of this new parameter should be carefully performed at the bracing initiation.

Association between braced curve behavior by pubertal growth peak and bracing effectiveness in female idiopathic scoliosis: a longitudinal cohort study

BACKGROUND

Pre-pubertal idiopathic scoliosis (IS) is associated with high risk of bracing ineffectiveness. Integrated multidimensional maturity assessments are useful but complex to predict the high-risk occurrence of curve progression. This study is designed to provide a simple screening method for brace effectiveness by determining whether or not the braced curve behavior at growth spurt, being defined as variations in Cobb angle velocity (AV) at peak height velocity (PHV), can be a new factor predictive of brace outcome prescribed before PHV.

METHODS

This is a retrospective study of a series of 35 IS girls with simplified skeletal maturity score no more than 3 at initiation of bracing treatment and followed up through the growth spurt until brace weaning or surgery. Serial Cobb angle and maturity indicators involving height velocity, Risser sign, triradiate cartilage, simplified skeletal maturity score and distal radius and ulna classification were assessed and patients were stratified into either a positive or negative category based on a positive or negative value of AV at PHV. Comparisons were made between the positive and negative AV groups, as well as the failed and successful bracing groups, using independent sample T test and crosstab analysis. Logistic regression analysis was used to identify the predictive factors of failed brace treatment.

RESULTS

Brace treatment prescribed before PHV was found to have an overall failure rate of 57.1% and a surgical rate of 45.7%. Negative AV at PHV accounting for 54.3% of the recruited patients were associated with lower brace failure rate (36.8% vs. 81.2%, p = 0.016) and surgical rate (21.1% vs. 75.0%, p = 0.002). Patients in the failed bracing group showed higher ratio of thoracic curve (80.0% vs. 26.7%,p = 0.002) and higher AV at growth peak (2.3 ± 9.1 vs. -6.5 ± 11.4°/yrs., p = 0.016). The logistic regression analysis revealed that positive AV at PHV (OR = 9.268, 95% CI = 1.279-67.137, p = 0.028) and thoracic curve type (OR = 13.391, 95% CI = 2.006-89.412, p = 0.007) were strong predictive factors of ineffective brace treatment initiated before PHV.

CONCLUSIONS

Sustained curve correction following bracing despite early onset and rapid pubertal growth was strongly predictive of effective brace control of scoliosis.

Brace Success Is Related to Curve Type in Patients with Adolescent Idiopathic Scoliosis

BACKGROUND

Curve magnitude and skeletal maturity are important factors in determining the efficacy of bracing for the treatment of adolescent idiopathic scoliosis, but curve morphology may also affect brace success. The purpose of this study was to determine the influence of curve morphology on the response to bracing with a thoracolumbosacral orthosis (TLSO).

METHODS

A retrospective review of patients managed with an orthosis for the treatment of adolescent idiopathic scoliosis who were prospectively enrolled at the initiation of brace wear and followed through completion of bracing or surgery was performed. Inclusion criteria were main curves of 25° to 45° and a Risser stage of 0, 1, or 2 at the time of brace prescription. Compliance with bracing was measured with Maxim Integrated Thermochrons. Radiographs made at brace initiation, brace cessation, and final follow-up were used to retrospectively categorize curves with use of the modified Lenke (mLenke) classification system and more broadly to categorize them as main thoracic or main lumbar. The effect of morphology on outcome was evaluated using chi-square and Fisher exact tests.

RESULTS

One hundred and sixty-eight patients were included. There was no difference in curve magnitude at the time of brace initiation (p = 0.798) or in average hours of daily brace wear (p = 0.146) between groups. The rate of surgery or progression of the curve to ≥50° was 34.5% (29 of 84) in mLenke-I curves, 54.5% (6 of 11) in mLenke-II curves, 29.4% (10 of 34) in mLenke-III curves, 17.6% (3 of 17) in mLenke-V curves, and 13.6% (3 of 22) in mLenke-VI curves. There were no mLenke-IV curves at the time of brace initiation. The rate of surgery or progression to ≥50° was 34.1% (44 of 129) in the combined thoracic group and 15.4% (6 of 39) in the combined lumbar group (p = 0.0277). In brace-compliant patients (>12.9 hours/day), the rate of surgery or progression to ≥50° was 30.3% (20 of 66) in main thoracic curves and 5.3% (1 of 19) in main lumbar curves (p = 0.0239). One-tenth of curves changed morphology during bracing. The rate of surgery or progression to ≥50° was 35.8% (43 of 120) in persistent main thoracic curves, 20.0% (6 of 30) in persistent main lumbar curves, 12.5% (1 of 8) in main thoracic curves that became main lumbar curves, and 0% (0 of 9) in main lumbar curves that became main thoracic curves (p = 0.0383).

CONCLUSIONS

Thoracic curves are at greater risk for brace failure than lumbar curves are despite similar initial curve magnitudes and average amount of daily brace wear. A change in curve pattern may imply flexibility and is associated with brace success. Patients with thoracic curves should be counseled accordingly.

LEVEL OF EVIDENCE

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

Curve progression risk in a mixed series of braced and nonbraced patients with idiopathic scoliosis related to skeletal maturity assessment on the olecranon

We aimed to determine the curve progression risk of idiopathic scoliosis in patients at the time of peak height velocity by plotting curve magnitudes against olecranon stages of skeletal maturation. Register data of 372 patients with juvenile or adolescent idiopathic scoliosis followed at 6-month intervals from onset of scoliosis to skeletal maturity were reviewed. At the onset of the pubertal growth spurt, curves greater than 30° have a 100% risk of progressing over 45° (P<0.0001). Curves 21-30° have a progression risk of 72.5% (P=0.0034). A curve progression velocity 6-10° per year represents a risk of 71.8% (P=0.0001) to require surgical treatment and a velocity greater than 10° per year represents a risk of 100% (P<0.0001). Plotting curve magnitudes against height measurements and the stages of olecranon maturation offers a reliable prediction of curve progression risk in idiopathic scoliosis during Risser 0.