A comparison between Boston brace and European braces in the treatment of adolescent idiopathic scoliosis (AIS) patients: a systematic review based on the standardised Scoliosis Research Society (SRS) inclusion criteria for brace treatment

PURPOSE

To compare the Boston brace and European braces using a standardised Scoliosis Research Society (SRS) inclusion criteria for brace treatment as well as consensus recommendations for treatment outcome.

METHODS

This was a systematic review that was carried out using MeSH terminology in our search protocol in PubMed, Cochrane Library, Scopus, Clinicaltrials.gov and Web of Science database between 1976 and 29th of Jan 2023. All studies that were included in this review had applied fully/partially the SRS inclusion criteria for brace wear. Outcome measures were divided into primary and secondary outcome measures.

RESULTS

3830 literatures were found in which 176 literatures were deemed relevant to the study once duplicates were removed and titles and abstracts were screened. Of these literatures, only 15 had fulfilled the eligibility criteria and were included in the study. 8 of the studies were Level IV studies, 5 were Level III studies and 2 studies were Level I studies (1 prospective randomised controlled trial (RCT) and 1 Quasi-RCT). The percentage of patients who avoided surgery for European braces ranged from 88 to 100%, whereas for Boston brace ranged from 70 to 94%. When treatment success was assessed based on the final Cobb angle > 45°, approximately 15% of patients treated with European braces had treatment failure. In contrast, 20-63% of patients treated with Boston brace had curves > 45° at skeletal maturity. The BrAIST study used a cut-off point of 50° to define failure of treatment and the rate of treatment failure was 28%. Curve correction was not achieved in most patients (24-51% of patients) who were treated with the Chêneau brace and its derivatives. However, none of the patients treated with Boston brace achieved curve correction.

CONCLUSION

Boston brace and European braces were effective in the prevention of surgery. In addition, curve stabilisation was achieved in most studies. Limitation in current literature included lack of studies providing high level of evidence and lack of standardisation in terms of compliance to brace as well as multidisciplinary management of brace wear.

Nighttime versus Fulltime Brace Treatment for Adolescent Idiopathic Scoliosis: Which Brace to Choose? A Retrospective Study on 358 Patients

The purpose of this study is to retrospectively compare the effectiveness of fulltime Boston Brace (BB) and Providence Nighttime Brace (PNB) treatments in moderate scoliotic curves (20-40°) at a single institution and to carry out analyses for different subgroups. Inclusion criteria: idiopathic scoliosis, age ≥ 10 years, curve 20-40°, Risser ≤ 3 or Sanders stage ≤ 6 and curve apex below T6 vertebra. Exclusion criteria: incomplete radiological or clinical follow-up and previous treatment. The primary outcome was failure according to the SRS outcome assessment: increase in main curve > 5° and/or increase in main curve beyond 45° and/or surgery. The subgroup analyses were secondary outcomes. In total, 249 patients in the PNB and 109 in the BB groups were included. The BB showed a higher success rate compared to the PNB (59% and 46%, respectively) in both crude and adjusted comparisons (p = 0.029 and p = 0.007, respectively). The subgroup analyses showed higher success rates in pre-menarchal females, thoracic curves and curves > 30° in the BB group compared to the PNB group. Based on the findings, fulltime braces should be the treatment of choice for more immature patients and patients with larger and thoracic curves while nighttime braces might be sufficient for post-menarchal females and patients with lumbar and smaller curves.

Boston vs. Providence brace in treatment of Adolescent Idiopathic Scoliosis

Adolescent idiopathic scoliosis (AIS) is a complex condition characterized by a lateral curvature and axial rotational deformity of the spine. Though bracing is effective, a need remains to identify the effect brace type has on spine curvature. To examine differences in patient demographics between the Boston and Providence brace, determine the corrective change in Cobb angle and RVAD and investigate the effect of brace type on curvature over time. A retrospective chart review was conducted of 105 patients diagnosed with AIS from 2013-2016 at CHW. Five spinal parameters were measured: Cobb angle, Risser, RVAD, kyphosis and lordosis. Data was collected before bracing, in-brace and at 24 months. A final treatment outcome of either Cobb angle correction (reduction >5°), stabilization (change ±5°) or progression (deterioration >5°) was then evaluated. Providence brace provided significantly greater in-brace thoracolumbar Cobb angle and RVAD reduction in comparison to the Boston brace (Cobb angle -21.9° vs. -12.5°; RVAD: -1.8° vs. 1.62°). Similarly, Providence users had a significantly smaller increase in Cobb angle and RVAD over time (Cobb angle: thoracic 14.2° vs. 15.0°; thoracolumbar 23.6° vs. 26.0°; RVAD: 5.2° vs. 8.5°). Ultimately, no significant difference in final treatment outcome was established between brace groups. Although the Providence brace provides less of an increase in thoracic and thoracolumbar curvatures over time, both braces are an effective treatment and achieve comparable outcomes. Selection of braces may vary with primary curve angle, curve location, patient compliance and quality of life.

Can we predict the behavior of the scoliotic curve after bracing in adolescent idiopathic scoliosis? Τhe prognostic value of apical vertebra rotation

PURPOSE

We aimed to recognize radiographic and clinical prognostic factors of scoliotic curve behaviour after bracing.

METHODS

Our prognostic study was based on the 25 years outcomes of a Boston braced AIS cohort between 1978 and 1993 that were previously reported. All patients were followed-up during bracing, at short term and 25 years post-bracing. We evaluated the impact of socio-demographic, clinical and radiological parameters on the loss of curve correction after bracing.

RESULTS

Seventy-seven patients were reevaluated at 25 years post-brace. The mean scoliotic curve was significantly increased after bracing until the 25 years follow-up (p < 0.001). The mean loss of curve correction between the end of bracing and long-term follow-up was independent on the curve type, apical vertebra, premenarcheal status at bracing, time and duration of bracing, Cobb angle before or after bracing. The mean apical vertebral rotation after bracing was significantly related to the loss of curve correction (Spearman ρ = 0.2, p = 0.049). Apical vertebral rotation (Perdriolle method) greater than 20° post-bracing had a three times higher chance of progression > 5° compared with lesser apical vertebral rotation (OR 3.071, CI 0.99-9.51). The rotation of the apical vertebra, type and magnitude of the scoliotic curve after bracing explained 27.4% of the variance in the loss of curve correction post-bracing (R square = 0.274, p < 0.001).

CONCLUSION

A scoliotic curve is expected to lose some correction after bracing. The apical vertebral rotation post-bracing mainly affected the long-term curve behaviour. Adolescents with apical vertebral rotation greater than 20° after bracing may need further attention.

LEVEL OF EVIDENCE

Prognostic study, Level II.

Evaluation of the efficiency of Boston brace on scoliotic curve control: A review of literature

Context: Bracing is one of the most important treatment approaches that have been utilized in patients with scoliosis. Boston brace used to manage a scoliotic curve especially in lumbar and thoracolumbar areas. Objective: The aim of this review was to evaluate the efficiency of Boston brace to control the progression of the curve based on the available literature. Methods: A search was carried out using the following databases including Scopus, ISI Web of knowledge, PubMed, Ebsco, and Embasco. The key words used for the search were Boston brace, Boston orthosis which were used in combination with scoliosis. Articles identified were screened based on titles and abstracts. The quality of the studies was evaluated using Black and Down tool. Data were summarized based on PICO style. Results: Based on the aforementioned key words, 18 papers were selected, in which 7 studies focused on efficiency of Boston brace, 3 papers focused on quality of life, 5 papers on finite element analysis and 3 papers on comparison of efficiency of Boston with other available braces. The quality of the selected studies varied between 14 and 21. Conclusion: The results of most of the studies support the efficiency of this brace to control the progression of scoliotic curve, especially for the curve between T6 and L2. The efficiency of this brace may be due to its rigid structure and also location and direction of the straps.

Efficacy of bracing in skeletally immature patients with moderate-severe idiopathic scoliosis curves between 40° and 60°

STUDY DESIGN

Retrospective case-series.

OBJECTIVES

To evaluate the outcomes of bracing in skeletally immature patients with moderate-severe idiopathic scoliosis (IS) curves ≥ 40°.

BACKGROUND

In contrast to prior beliefs, the recent studies have reported successful outcomes with brace treatment may occur in some patients with moderate-severe scoliosis ≥ 40°. Despite other encouraging case-series, non-operative treatment is rarely attempted and the efficacy of bracing large curves remains uncertain.

METHODS

100 skeletally immature children (mean 11.8 ± 2.36 years; range 6.1-16.5) with IS ≥ 40° were identified. 80 were adolescent IS (80%) and 20 juvenile IS (20%). The Risser plus score was used to evaluate skeletal maturity. 66 children were Risser 0 (66%). SRS-SOSORT outcome guidelines were used: > 5° progression, stabilization between - 5° and 5° and, > 5° improvement.

RESULTS

Mean initial Cobb was 45° ± 3.9° (range 40°-59°), with in-brace and  % correction of 30° ± 8.7° (range 7°-48°) and 34 ± 17.5% (range 2-84%), respectively. 57 progressed (57%), 32 stabilized (32%), and 11 improved (11%) after a median of 1.8 years (IQR 1.2-2.9). Open triradiate cartilage at presentation (p = 0.005) and less in-brace correction (p = 0.009) were associated with progression. 58 children (58%) underwent surgery after a mean of 3.0 years (range 0.7-7.3). Surgical patients were younger (11.2 vs. 12.7 years; p = 0.003), more often Risser 0 (79% vs. 48%; p < 0.001); however, presented with similar curves (45° vs. 44°; p = 0.31). Open triradiate cartilage at presentation (OR 15.3; 95% CI 4.3-54.6; p < 0.001) and less in-brace correction (p = 0.03) increased the likelihood of surgery. All 20 JIS patients avoided temporary growth rods, with 18 (90%) eventually requiring surgery.

CONCLUSION

Non-operative treatment was successful in 42% of children. Risk factors for surgery were younger age, open triradiates, and less in-brace correction. Bracing can be effective in delaying surgery until skeletal maturity in patients with curves ≥ 40°. Patients should be counseled on the risks and benefits of bracing and surgery.

LEVEL OF EVIDENCE

Level IV.

Radiographic Outcomes of Immobilization using Boston Brace for Pediatric Spondylolysis

BACKGROUND AND AIMS

Spondylolysis is a common cause of lower back pain during youth. The aim of this study is to report the bony union rate and risk factors for non-union of the lumbar spondylolysis of pediatric patients treated with a rigid thoracolumbosacral orthosis (Boston brace).

MATERIALS AND METHODS

A retrospective review of 68 children (mean age = 13.9 years) treated for spondylolysis with a thoracolumbosacral orthosis. Patient charts and imaging studies were evaluated to identify the bony union rate of the spondylolysis after a minimum of 3 months of immobilization (mean = 4.2 months). Laterality, grade, level, and presence of high signal intensity in the magnetic resonance imaging were evaluated as prognostic factors.

RESULTS

Sixty-eight patients presented with 110 defects. Of them, 46 (42%) were incomplete fractures, 38 (35%) complete fractures, and 26 (24%) pseudoarthrosis. Of these defects, 38 (82.6%), 11 (28.9%), and 0 (0.0%) had bony union at the end of the treatment (p < 0.001). Unilateral defects healed significantly better than bilateral ones (relative risk = 1.71, 95% confidence interval = 1.16-2.54, 17/26 (65%) vs 32/84 (38%), p = 0.014). High signal intensity in the magnetic resonance images before the treatment predicted healing (relative risk = 13.24, 95% confidence interval = 1.93-91.01, 48/87 (55%) vs 1/24 (4.3%), p < 0.001). The level of the spondylolysis (L5 vs above L5) did not affect the healing rate.

CONCLUSION

The union rates of spondylolysis with a thoracolumbosacral orthosis were similar as compared to earlier studies done with a low thoracolumbosacral orthosis. The grade of the defect, laterality, and presence of high signal intensity increased the probability of bony union. A high thoracolumbosacral orthosis (underarm) does not seem to improve the healing rate of pediatric spondylolysis defects.

LETTER TO THE EDITOR CONCERNING: Effectiveness of the Rigo Chêneau versus Boston-style orthoses for adolescent idiopathicscoliosis: a retrospective study, by Minsk MK, Venuti KD, Daumit GL, Sponseller PD. Scoliosis Spinal Disord. 2017 Mar 20;12:7

We have read with great interest the article by Minsk et al. in Scoliosis and Spinal Disorders. However, the authors reported a conclusion that is based on possible selection bias in surgical candidates. Physicians are trained in the interpretation of scientific articles; however, not everybody is able to do this. Especially in open access journals, a biased conclusion may have big consequences and may be misleading for patients and family members who can read these articles for free on the internet.

Curve progression 25 years after bracing for adolescent idiopathic scoliosis: long term comparative results between two matched groups of 18 versus 23 hours daily bracing

Background

Scoliotic curves do not necessarily stop progressing at skeletal maturity. The factors that influence curve behavior following bracing are not fully determined. Our objectives were to evaluate the loss of the scoliotic curve correction in a cohort of patients treated with bracing during adolescence and to compare the outcomes of 18 versus 23 h of bracing at a mean of 25 years post brace removal.

Methods

Seventy-seven patients, who were successfully treated for Adolescent Idiopathic Scoliosis with Βoston brace, were re-evaluated 25 years after the end of their treatment. Patients were further divided in 2 matched groups; those wearing the brace for 23 h and those not wearing the brace at school-time, limiting the application of the brace to 18 h. The mean scoliotic curve was compared between groups before, during, just after bracing and 25 years post bracing. Validated in patients’ native language forms of Short Form 36 and Oswestry Disability Index questionnaires were used to compare the quality of life between groups 25 years post bracing.

Results

The mean age of the cohort was 40.4 (±3.2) years. They underwent long term follow up at a mean of 25.16 (±2.69) years after brace removal. The mean cohort scoliotic curve increased by 3.9 (±6.69) at 25 years since brace removal. There was however no significant difference in the mean Cobb angle of the cohort between pre brace and long term follow up period (p = 0.307).

The 18 and 23 h application groups were comparable according to demographics and several bracing and scoliotic curve parameters. There was no significant difference in the mean curve magnitude between 18 and 23 h application groups at brace removal (p = 0.512) and at 25 years follow-up (p = 0.878). There was also no significant difference in the mean score of Quality of Life questionnaires between groups at long term follow up.

Conclusion

Scoliotic curves do not necessarily stop progressing after bracing. Bracing is effective treatment method with good long term results in appropriate patients. Since compliance was not objectively measured, we don’t feel confident to give any indication about everyday dosage.