Predictive factors of Osaka Medical College (OMC) brace treatment in patients with adolescent idiopathic scoliosis

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.

Impact of Brace-Related Stress on Brace Compliance in Adolescent Idiopathic Scoliosis: A Single-Center Comparative Study Using Objective Compliance Measurement and Brace-Related Stress

Introduction

This study aimed to investigate the brace compliance and clinical background of patients with adolescent idiopathic scoliosis (AIS) who demonstrate different degrees of psychological brace-related stress.

Methods

Forty-five patients initiating brace treatment with a Cobb angle between 25° and 45° were included. Patients receiving brace treatment for AIS were administered a questionnaire for brace-related stress (i.e., the Japanese version of the Bad Sobernheim Stress Questionnaire-Brace [JBSSQ-brace]). Based on their scores, we allocated the patients into two stress groups: mild-stress (≥16 points) and below-moderate-stress (<16 points). We investigated the character of brace compliance and brace-related psychological stress in all patients and compared the demographics and brace compliance between both groups.

Results

Forty-one of 45 patients completed the study. The mean JBSSQ-brace scores were 18.7±5.1, 19.1±5.2, and 18.7±5.0 points at the 1-month, 4-month, and 1-year follow-ups, respectively. There was no significant change in JBSSQ-brace scores over one year after the brace prescription (P=0.332). There was no difference in-brace compliance between seasons during the first month of brace prescription (P=0.252). Both groups' overall brace compliance was comparable (below-moderate: 17.1±7.1 h/day vs. mild: 20.4±3.0 h/day; P=0.078). The mild-stress group showed better compliance than the below-moderate-stress group on weekdays (below-moderate: 17.0±6.9 h/day vs. mild: 20.5±2.8 h/day; P=0.048) and at nighttime (below-moderate: 82.3%±27.0%/nighttime vs. mild: 93.8%±12.4%/nighttime; P=0.008).

Conclusions

Overall, brace compliance was comparable among patients with different brace-related stress, but brace compliance during weekdays and nighttime was significantly better in the mild-stress group.

Nonoperative management of adolescent idiopathic scoliosis (AIS) using braces

This review presents the state of the art according to the current evidence on nonoperative treatment for adolescent idiopathic scoliosis, focusing on bracing. The definition of braces for the treatment of adolescent idiopathic scoliosis and a short history are provided. The analysis includes biomechanics, types, existing classifications, indications for treatment, time of brace wear and weaning, adherence, three-dimensional modeling, use of ultrasound imaging for bracing, management of treatment, issue of immediate in-brace correction, and documentation of the outcomes usually assessed for brace treatment, including the quality-of-life issues. According to the current evidence, there are two randomized control trials in favor of bracing. There are insufficient data on the superiority of one brace over another, although it is possible to classify and grade braces for efficacy from nonrigid to rigid and very rigid. Nevertheless, there is consensus on patients' management on the need for teamwork focusing on adherence to treatment, acceptability, and family and patient involvement.

The Effectiveness of Different Concepts of Bracing in Adolescent Idiopathic Scoliosis (AIS): A Systematic Review and Meta-Analysis

Brace treatment is the most common noninvasive treatment in adolescent idiopathic scoliosis (AIS); however it is currently not fully known whether there is a difference in effectiveness between brace types/concepts. All studies on brace treatment for AIS were searched for in PubMed and EMBASE up to January 2021. Articles that did not report on maturity of the study population were excluded. Critical appraisal was performed using the Methodological Index for Non-Randomized Studies tool (MINORS). Brace concepts were distinguished in prescribed wearing time and rigidity of the brace: full-time, part-time, and night-time, rigid braces and soft braces. In the meta-analysis, success was defined as ≤5° curve progression during follow-up. Of the 33 selected studies, 11 papers showed high risk of bias. The rigid full-time brace had on average a success rate of 73.2% (95% CI 61-86%), night-time of 78.7% (72-85%), soft braces of 62.4% (55-70%), observation only of 50% (44-56%). There was insufficient evidence on part-time wear for the meta-analysis. The majority of brace studies have significant risk of bias. No significant difference in outcome between the night-time or full-time concepts could be identified. Soft braces have a lower success rate compared to rigid braces. Bracing for scoliosis in Risser 0-2 and 0-3 stage of maturation appeared most effective.

It is not just about the frontal plane: sagittal parameters impact curve progression in AIS patients undergoing brace treatment

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The purpose of this study was to explore the association between pre-brace and in-brace sagittal parameters and curve progression. To date, there has been no published research focused on spinopelvic sagittal parameters and bracing outcomes in AIS. We hypothesize that sagittal spinopelvic parameters are associated with curve progression at 2 years.

METHODS

This study included AIS patients with a pre-brace (PB) major curve between 20° and 45°. The outcome was defined as > 10° curve progression or surgery within 2 years of brace initiation. Spinopelvic parameters included C7-Central Sacral Vertebral Line shift (C7-CSVL), thoracic trunk shift, lumbar lordosis (LL), pelvic incidence (PI), T2-T12 thoracic kyphosis (TK) pelvic incidence-lumbar lordosis (PI-LL) mismatch, sagittal vertical axis (SVA), and pelvic tilt (PT).

RESULTS

Of 50 patients included in this review, [70% Rigo (RCSO) and 30% Boston (BSO)], 16 (32%) patients demonstrated progression (23% of patients with RCSO vs 53% with BSO; p = 0.034). In patients with more than 30% major coronal curve correction (CCC), 23% had progression. 45% of patients progressed when they achieved ≤ 30% correction (p = 0.108). Among PB sagittal parameters and adjusting for coronal curve, patients with an abnormal PB SVA had 3.1 times increased risk of treatment failure compared with patients who had a normal PB SVA. Patients with PB hypo-LL had a 2.8 times increased risk of treatment failure compared with patients who had normal or hyper-LL. Among IB sagittal parameters, patients who had a normal PB PI-LL had a 3.9 times increased risk of treatment failure when they became mismatched in-brace (IB). Patients who had normal pre-brace kyphosis who became hypo-kyphotic IB had an 8.4 times increased risk of treatment failure compared with patients who maintained normal TK or became hyper-kyphotic.

CONCLUSION

These data suggest that we should pay careful attention to sagittal parameters prior to and during brace treatment as braces can control these parameters.

LEVEL OF EVIDENCE

Level III.

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.

3D spinal and rib cage predictors of brace effectiveness in adolescent idiopathic scoliosis

Background

Scoliotic braces are the standard of curve for management of moderate spinal deformities in pediatric patients. The effectiveness of this treatment method has been shown; however, the spinal and rib cage parameters, in the three anatomical planes, that are associated with bracing outcome in adolescent idiopathic scoliosis (AIS) are not fully identified.

Methods

A total number of 45 right thoracic AIS patients who had received a thoraco-lumbo-scaral brace for the first time were included retrospectively. For each patient, radiographic images at three visits, pre-brace, in-brace, and at least 1 year after the first brace fit were included. Age, sex, Risser sign, and curve type at pre-brace, and thoracic and lumbar frontal and sagittal Cobb angles, thoracic and lumbar apical rotations, sagittal and frontal balances at pre-brace and in-brace were determined. Two sagittal curve types (hypothoracolumbar and normal/hyperthoracolumbar kyphosis), two rib cage types based on the costovertebral joints (drooping and horizontal), and two axial shapes of the spine (S shaped and V shaped) were used to stratify the patients. Feature selection and linear regression with regularization determined the parameters and the interaction terms that predicted the brace effectiveness significantly.

Results

Smaller in-brace thoracic Cobb and larger in-brace lordosis predicted brace effectiveness, p < 0.05. Impact of the out of brace lordosis on the brace success increased as the in brace kyphosis angle decreased, p = 0.046. A larger out of brace lordosis in hypothoracolumbar sagittal profile type patients improved the outcomes, p = 0.031. A smaller out of brace thoracic rotation improved the bracing outcomes in patients with horizontal ribs, p = 0.040.

Conclusion

Both 3D patient specific parameters (lordosis, thoracic rotation, shape of the rib cage, and sagittal profile) and brace design (which allows larger in brace lordosis, better in brace Cobb correction) are important predictors of the brace effectiveness in AIS.

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2754-2) contains supplementary material, which is available to authorized users.

Factors That Influence In-Brace Correction in Patients with Adolescent Idiopathic Scoliosis

OBJECTIVE

To identify the factors affecting in-brace correction in patients with adolescent idiopathic scoliosis (AIS).

METHODS

We performed a retrospective analysis of patients with AIS receiving Gensingen brace treatment in our scoliosis center from July 2015 to October 2017 was performed. The selection of patients was in accordance with the Scoliosis Research Society inclusion criteria for a bracing study. Some radiographic and clinical parameters, including the Cobb angle, rib-vertebra angle difference, coronal and sagittal balance, lumbar-pelvic relationship (LPR), Risser sign, curve type, age, gender, height, weight, body mass index, and menstrual status were collected. The correlation and difference analyses were performed to identify the factors influencing in-brace correction.

RESULTS

A cohort of 112 patients with AIS (94 girls and 18 boys) were included in the present study. The mean in-brace correction was 59.29% ± 22.33% (range, 16.22%-100.00%). In-brace correction showed a significantly negative correlation with the major curve Cobb angle, minor curve Cobb angle, total curve Cobb angle, and LPR (P < 0.05 for all). Sagittal and coronal imbalance could reduce the curve correction (P < 0.001 and P = 0.008, respectively). The remaining parameters were not related to in-brace correction.

CONCLUSIONS

In-brace correction in the present study was 59.29% ± 22.33% (range, 16.22%-100.00%). Some factors, including the Cobb angle, sagittal and coronal balance, and LPR, have an effect on in-brace correction. The results from the present study can provide some useful information for brace design and fabrication.

Retrospective analysis of idiopathic scoliosis medical records coming from one out-patient clinic for compatibility with Scoliosis Research Society criteria for brace treatment studies

Background

First author attempted to analyse medical records of patients with idiopathic scoliosis for compliance with the Scoliosis Research Society brace studies criteria. A retrospective analysis of medical records of 2705 girls treated from 1989 to 2002 was carried out.

Methods

Age, Cobb, Risser and menarchal status were analyzed for compliance with the Scoliosis Research Society brace studies criteria: a) age ≥10 years, b) Risser 0–2, c) 25–40° Cobb angle, d) no earlier treatment, e) patients before first menses or not more than one year from first menses.

Results

It has been found that 183 girls out of 2705 were ≥10 years old and in the range 25–40° Cobb angle. One hundred two out of 2705 patients revealed eligible for brace effectiveness study according to SRS 2005 criteria. 120 out of 2705 patients revealed eligible for brace brace effectiveness study according to SRS-SOSORT 2014 criteria.

Conclusion

The excluded patients revealed too old or with too significant Cobb angles. This indicates the changing criteria for scoliosis brace treatment over the time. Direct comparison of current results of brace treatment with historical series of cases turns out to be very difficult.

Impact of Rotation Correction after Brace Treatment on Prognosis in Adolescent Idiopathic Scoliosis

Study Design

Level 4 retrospective review.

Purpose

Brace treatment is the standard nonoperative treatment for adolescent idiopathic scoliosis (AIS). Rotation correction is also important, because AIS involves a rotation deformity. The purpose of this study was to evaluate the impact of rotation correction after Osaka Medical College (OMC) brace treatment on clinical outcomes in AIS.

Overview of Literature

Brace treatment has a significant effect on the progression of AIS. However, few reports have examined rotation correction after brace treatment.

Methods

A total of 46 patients who wore the OMC brace were retrospectively reviewed. The curve magnitude was determined according to the Cobb method, and the rotation angle of the apical vertebrae was measured by the modified Nash-Moe method. Based on the difference in the rotation angle before and after the initial brace treatment, patients were divided into two groups. Group A (n=33) was defined as no change or improvement of the rotation angle; group B (n=13) was defined as deterioration of the rotation angle. If the patients had curve or rotation progression of 5° or more at skeletal maturity, or had undergone surgery, the treatment was considered a failure.

Results

Differences of rotation angle between before and after the initial brace treatment were 2°±2° in group A and –3°±2° in group B (p<0.001). The rates of treatment failure were 42% in group A and 77% in group B (p<0.05). This study included 25 patients with Lenke type 1 (54%). Group A (24%) with Lenke type 1 also had a significantly better success rate of brace treatment than group B (75%) (p<0.05).

Conclusions

Insufficient rotation correction increased brace treatment failure. Better rotation correction resulted in a higher success rate of brace treatment in patients with Lenke type 1.