The effectiveness of the SpineCor brace for the conservative treatment of adolescent idiopathic scoliosis. Comparison with the Boston brace

Abstract

Background ContextThe Boston brace (Bb) is the most widely used brace design to treat adolescent idiopathic scoliosis (AIS). The dynamic SpineCor (SC) brace is prescribed in several scoliosis clinics worldwide, but its effectiveness remains controversial. PurposeThe study aimed to compare the treatment effectiveness of SC in patients with AIS treated by the developers of the brace with that of the Bb at a single institution. Study Design/SettingThis is a retrospective comparison between a cohort of AIS patients treated using the SC brace and a cohort treated using the Bb. Patient SampleWe assessed 243 patients treated with either Bb or SC brace to prevent the progression of AIS. Outcome MeasuresThe primary outcome was the progression in main Cobb angle when reaching one of the following end point criteria: (1) progression in Cobb angle of ≥6°, (2) main Cobb angle of ≥45°, (3) surgery undertaken, or (4) reaching skeletal maturity (Risser sign of 5 or growth of <1 cm in the previous 6 months). MethodsPatients were identified at a single institution between 2000 and 2012 following the Scoliosis Research Society criteria for brace treatment: (1) diagnosis of AIS, (2) Risser sign of ≤2, (3) curve magnitude between 25° and 40°, and (4) age ≥10 years. A total of 97 patients treated with SC by the developers of the brace and 146 patients treated with Bb were identified. Data collection and radiograph measurements were performed by a single experienced nurse not involved in the decision-making for brace treatment or in the data analysis. Age and Risser sign at onset of treatment, initialmain Cobb angle, curve type, and duration of follow-up were similar in both cohorts. Statistical analysis was done using chi-square and logistic regression models, with a level of significance of .05. ResultsThe average progression was 14.7°±11.9° in the SC cohort compared with 9.6°±13.7° in the Bb cohort (p=.003). The average Cobb angle at the end point of the study reached 47°±13° in the SC cohort and 41.7°±14.2° in the Bb cohort (p=.005), whereas at the onset of bracing it was 32.2°±4.9° and 32.2°±4.4°, respectively, for the SC and Bb cohorts. The percentage of patients with a progression of ≥6° was 76% in the SC cohort and 55% in the Bb cohort (p=.001). The proportion of patients reaching 45° in the SC and Bb cohorts was, respectively, 51% and 37% (p=.03), whereas the proportion of patients referred to surgery was 39% and 30%, respectively, for the SC and Bb cohorts (p=.2). The odds of progressing ≥6° and of reaching ≥45° were 2.67 and 2.07 times greater, respectively, when using the SC brace. ConclusionsThe SC brace did not prevent curve progression as effectively as the Bb. Although it has the potential benefit of increasing mobility during brace wear, the SC brace was associated with increased curve progression in comparison with the Bb. There is also a trend for increased risk of requiring surgery when the SC brace is worn.