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

Identifying predictors of brace treatment outcomes for adolescents or adults with idiopathic scoliosis: a systematic review

PURPOSE

This systematic review aimed to identify predictors of brace treatment outcomes for adolescents or adults with idiopathic scoliosis.

METHODS

Four databases including MEDLINE, EMBASE, Web of Science, and CINAHL were searched. Free text and indexed terms identifying the populations, predictions analyses and key outcomes were combined to search the literature. Pairs from eight independent reviewers conducted abstracts and full-text screening, and data extraction. The Quality in Prognostic Studies (QUIPS) tool was used to assess the risk of bias (ROB). Strength of evidence summary statements were formulated based on the risk of bias and the consistency of the research findings.

RESULTS

The search found 2224 articles. After screening, seven articles were included. Only one article showed low ROB, while the others showed moderate ROB. All articles reported on patient-related outcome measurements (PROMS) of quality of life (QOL). Only one parameter achieved limited strength of evidence; shorter treatment time from one study predicted better long-term SRS-22 total scores. For other predictors, the level of evidence was unclear. Other predictors of long-term outcomes (> 1 year follow-up), from only 1 study on each outcome, were: larger Cobb angle predicted worse Spinal Appearance Questionnaire (SAQ) chest scores and worse depression; higher age predicted better SAQ curve scores, larger apical translations predicted worse SAQ shoulders and chest scores; a passive introverted personality or an active outgoing (MPI) character type predicted worse SRS-22 satisfaction; higher BMI predicted better SAQ curve, Rolland-Morris questionnaire (RMQ) lumbosacral pain, Quebec Back Pain Disability Scale (QDS) moving scores, and worse SRS-22 total; larger vital capacity predicted better QDS score; longer bracing (total) predicted worse depression; negative parental attitudes predicted worse depression; higher Strengths and Difficulties Questionnaire emotional symptoms, peer problems, prosocial behavior, and total scores predicted worse depression. Poor compliance from one short-term follow-up study predicted worse change of brace questionnaire (BRQ) for health perception, pain, physical and emotional functioning, and total scores. Moderate evidence from two studies with low and moderate RoB showed that age and Cobb angle did not predict long-term total SRS-22 score for prediction.

CONCLUSION

Eleven parameters predicted bracing outcomes, but most studies presented moderate risk of bias. Only one parameter, longer treatment time, with limited strength of evidence was predictive of better long-term SRS-22 total scores. Since most findings still present an unclear level of evidence, common weaknesses were identified to encourage design of high-quality studies predicting bracing outcomes.

Predicting Surgical and Non-surgical Curvature Correction by Radiographic Spinal Flexibility Assessments for Patients With Adolescent Idiopathic Scoliosis: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic Review and Meta-analysis.

OBJECTIVES

This systematic review and meta-analysis aimed to: (1) synthesize the prevalent application ratios of 2 radiographic spinal flexibility assessment methods in AIS patients treated with PSF or bracing; and (2) quantitatively evaluate the accuracy of these methods in predicting post-intervention correction outcomes.

METHODS

A systematic search was conducted across 5 electronic databases: CINAHL, Embase, Ovid, PubMed, and Web of Science. Meta-analyses were performed to investigate the accuracy of the spinal flexibility rate in predicting the post-intervention correction rate in AIS patients treated with PSF surgery or bracing, using RevMan 5.4.1 software.

RESULTS

The results of 31 studies, involving 1868 AIS patients, showed that the side-bending method was utilized more frequently than the fulcrum-bending method in both treatments. Meanwhile, the spinal flexibility evaluated by the fulcrum-bending method may provide a more accurate prediction of post-surgical correction compared to the side-bending approach, particularly for main curves. For the bracing treatment, only a few studies have preliminarily reported good capability of the side-bending method in predicting the initial in-brace correction.

CONCLUSIONS

This review quantitatively assessed the clinical application ratio and effectiveness of side-bending and fulcrum-bending radiographs in predicting post-intervention curve corrections in AIS patients undergoing surgical or bracing treatments. The results of the current review supported to adopt the fulcrum-bending approach for AIS patients undergoing PSF surgery with main thoracic curves, and the side-bending approach for those with thoracolumbar/lumbar curves. For patients receiving bracing treatment, further research is still needed to confirm the clinical value of the side-bending method.

Comparison of the efficacy of thoracolumbosacral and lumbosacral orthosis for adolescent idiopathic scoliosis in patients with major thoracolumbar or lumbar curves: a prospective controlled study

Introduction

Thoracolumbosacral orthosis (TLSO) is the most commonly used type of brace for the conservative treatment of adolescent idiopathic scoliosis (AIS). Although lumbosacral orthosis (LSO) is designed to correct single thoracolumbar or lumbar (TL/L) curves, its effectiveness remains underexplored. This novel article aims to compare the effectiveness of LSO with TLSO in treating AIS with main TL/L curves.

Methods

This prospective controlled cohort study enrolled patients with AIS with main TL/L curves and minor thoracic curves who were treated with either TLSO or LSO. Demographic and radiographic data were compared between the two groups. Treatment outcomes were also assessed. Risk factors for minor curve progression were identified, and a cut-off value was determined within the LSO group.

Results

Overall, 82 patients were recruited, including 44 in the TLSO group and 38 in the LSO group. The initial TL/L curves showed no difference between both groups. However, the baseline thoracic curves were significantly larger in the TLSO group compared to the LSO group (25.98° ± 7.47° vs. 18.71° ± 5.95°, P < 0.001). At the last follow-up, LSO demonstrated similar effectiveness to TLSO in treating TL/L curves but was less effective for thoracic curves. The initial magnitude of thoracic curves was identified as a risk factor for minor curve outcomes in the LSO group. The ROC curve analysis determined a cut-off value of 21° for thoracic curves to predict treatment outcomes.

Discussion

In contrast to TLSO, LSO exhibits comparable effectiveness in treating main TL/L curves, making it a viable clinical option; however, it is less effective for thoracic minor curves. The initial magnitude of the minor thoracic curves may guide the selection of the appropriate brace type for patients with AIS with main TL/L curves.

Associations between spinal flexibility and bracing outcomes in adolescent idiopathic scoliosis: a literature review

OBJECTIVES

To identify the existing assessment methods used to measure the spinal flexibility of adolescents with idiopathic scoliosis before bracing and to evaluate the predictive effect of spinal flexibility on bracing outcomes.

METHODS

A broad literature search was performed in the PubMed, Web of Science, EMBASE, CINAHL, Scopus, and Cochrane Library databases to obtain relevant information about spinal flexibility and bracing outcomes. All literature was retrieved by October 14, 2023. The inclusion and exclusion criteria were meticulously determined. The quality of each included study and the level of evidence were evaluated by the Quality in Prognosis Studies (QUIPS) method and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system, respectively.

RESULTS

After screening 1863 articles retrieved from databases, a total of 14 studies with 2261 subjects were eligible for the final analysis in this review. Overall, nine methods of flexibility assessment were identified, including supine radiographs, supine lateral bending radiographs, lateral bending radiographs but without clear positions, hanging radiographs, fulcrum bending physical method, and ultrasound imaging in the positions of supine, prone, sitting with side bending and prone with side bending. In addition, five studies demonstrated that flexibility had a strong correlation with in-brace correction, and eleven studies illustrated that spinal flexibility was a predictive factor of the bracing outcomes of initial in-brace Cobb angle, initial in-brace correction rate, curve progression, and curve regression. The results of GRADE demonstrated a moderate-evidence rating for the predictive value of spinal flexibility.

CONCLUSION

Supine radiography was the most prevalent method for measuring spinal flexibility at the pre-brace stage. Spinal flexibility was strongly correlated with the in-brace Cobb angle or correction rate, and moderate evidence supported that spinal flexibility could predict bracing outcomes.

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.

Does Risser Casting for Adolescent Idiopathic Scoliosis Still Have a Role in the Treatment of Curves Larger Than 40°? A Case Control Study with Bracing

Background: The most common conservative treatment for Adolescent Idiopathic Scoliosis (AIS) is bracing. However, several papers questioned the effectiveness of bracing for curves between 40° and 50° Cobb: the effectiveness in preventing curve progression could be as low as 35%. Seriate casting is considered a standard approach in early onset scoliosis; however, in the setting of AIS, cast treatment is seldom utilized, with only few studies reporting on its effectiveness. Aim of the study: The main aim of the study is to determine whether a seriate casting with Risser casts associated with bracing is more effective in preventing curve progression than bracing alone in curves larger than 40°. Furthermore, the secondary endpoints were: (1) is there a difference in effectiveness of casting between Thoracic (T) and Thoracolumbar/Lumbar (TL/L) curves? (2) Does the ‘in cast’ correction predicts the treatment outcome? (3) What is the effect on thoracic kyphosis of casting? Methods: This is a retrospective monocentric case−control study; through an Institutional Database search we identified all the patients treated at our institution between 1 January 2017 and 31 December 2020, with a diagnosis of AIS, Risser grade between 0 and 4 at the beginning of the treatment, at least one curve above 40° Cobb and treatment with either seriate Risser casting and bracing (Study Group, SG) or bracing alone (Control Group, CG). Standing full spine X-rays in AP and LL are obtained before and after the cast treatment; only AP standing full spine X-rays ‘in-cast’ are obtained for each cast made. Patients were stratified according to the curve behavior at the end of treatment (Risser 5): progression was defined as ≥6° increase in the curve magnitude or fusion needed; stabilization is defined as a change in curve by ±5°; and improvement was defined as ≥6° reduction in the curve. Results: For the final analysis, 55 compliant patients (12 M, 43 F, mean age 13.5 ± 1.6) were included in the SG and 27 (4 M, 23 F, mean age 13.6 ± 1.6) in the CG. Eight (14.5%) patients in the SG failed the conservative treatment while 14 (51.3%) failed in the CG. Consequently, the Relative Risk for progression in the Efficacy Analysis was 1.8 (95% CI 1, 3−2.6, p = 0.001), and the Number Needed to Treat was 2,4. No significant difference was found between the T and TL/L curves concerning the ‘progressive’ endpoint (z-score 0.263, p = 0.79). The mean percentage of ‘in cast’ curve reduction was 40.1 ± 15.2%; no significant correlation was found between the percentage of correction and the outcome (Spearman Correlation Coefficient 0.18). Finally, no significant differences between baseline and end of FU TK were found (32° ± 16.2 vs. 29.6 ± 15.8, p = ns). Discussion: Seriate Risser casting for AIS with larger curves (>40° Cobb) is effective in reducing curve progression when compared with full time bracing alone in treatment compliant patients. The treatment is equally effective in controlling T and TL/L curves; furthermore, a slight but non-significant decrease in TK was observed in patients treated with casting. This type of treatment should be considered for AIS patients who present with large curves to potentially reduce the percentage of surgical cases. Short Abstract: The aim of the study is to determine whether seriate Risser casting associated with bracing is more effective in preventing curve progression than bracing alone in curves larger than 40°. This is a retrospective monocentric case−control study; we identified all the patients treated at our institution with a diagnosis of AIS, Risser grade 0−4 at the beginning of the treatment, at least one curve above 40° Cobb (35° if treated with bracing alone) and treatment with either seriate Risser casting and bracing (Study Group, SG) or bracing alone (Control Group, CG). Fifty-five patients (12 M, 43 F, mean age 13.5 ± 1.6) were included in the SG and 30 (5 M, 25 F, mean age 13.9 ± 1.7) in the CG. Eight (14,5%) patients in the SG failed the conservative treatment while fifteen (50%) failed in the CG. Consequently, the Relative Risk for progression in the Efficacy Analysis was 1.8 (95% CI 1.3−2.6, p = 0.001), and the Number Needed to Treat was 2,4. Seriate Risser casting for AIS with larger curves (>40°) is effective in reducing curve progression when compared with full time bracing alone. This type of treatment should be considered for AIS patients who present with large curves.

Scoliosis: Causes and Treatments

Scoliosis is an abnormal curvature of the spine, which generally develops during childhood or adolescence. It affects 2–4 percent of the global population and is more prevalent among girls. Scoliosis is classified by its etiology: idiopathic, congenital, or neuromuscular. Among these, the former is the most common. Treatment options for scoliosis vary depending on the severity of the curve. Most scoliosis diagnoses tend to be mild and only require monitoring. However, curves between 20 and 40 degrees require bracing, while 40 degrees and above require surgery. There are various bracings available, such as Boston, Charleston, and Milwaukee. In severe cases of scoliosis, either fusion or fusionless surgery may be required. This review aims to discuss etiologies and different treatment interventions for scoliosis.