BACKGROUND: Adolescent Idiopathic Scoliosis (AIS) requires complex medical care because of multiple consequences especially on daily activities. Muscular involvement is part of the problem and may be treatable. OBJECTIVE: To analyze trunk muscle strength using an isokinetic dynamometer in female adolescents with AIS one year after orthopedic treatment by brace and compare the findings to a matched group of an asymptomatic cohort. METHODS: The trunk flexors and extensors strength was measured using an isokinetic dynamometer at 60, 90 and 120∘/s. Peak Moment (PM), Mean Power (MP) and the flexor/extensor ratio in 100 patients aged 14 to 18 years old were compared to a control group (N= 32) of asymptomatic age-matched females. In the AIS group, correlation analyses were computed to search for contributing factors to isokinetic performances, including morphological characteristics of patients, as well as clinical and radiological characteristics of the scoliosis. RESULTS: The trunk flexors in the AIS group were significantly but moderately (15%) weaker across speeds compared to their control counterparts at all speeds. No parallel weakness was noted for the extensors. While the MP of AIS patients was significantly weaker than that of the controls, 33% for flexors and by 31% for extensors, no significant differences were observed for the F/E ratios. The correlational analyses has indicated that weight and BMI were contributing factors at all speeds. CONCLUSION: Adolescents with AIS had weaker trunk extensors and mostly flexors compared to healthy females. Within this AIS population, weight and BMI seem to have a negative impact on muscular performances, whereas clinical and radiological characteristics of the scoliosis do not seem to contribute.

Background: The results of 12 h nighttime Cheneau–Toulouse–Munster (CTM) brace wear on adolescent idiopathic scoliosis are poorly described. Objective: The main objective was to analyze the efficiency of 12 h nighttime CTM brace wear on adolescent idiopathic scoliosis. The secondary objective was to identify the factors influencing good results. Methods: One hundred and fifty consecutive patients treated between 2006 and 2017 were retrospectively analyzed with subgroup analysis for the main curve pattern (main thoracic or main lumbar). The inclusion criteria were evolutive scoliosis, 12 h nighttime CTM brace wear, Risser stages 0-1-2 at the time of the prescription, and Cobb angle below 45 degrees. Success was defined as no surgery, and the main curve Cobb angle (CA) progression ≤5°. The overcurve was defined as the proximal thoracic curve above the main thoracic and mid-thoracic above the main lumbar curves. A logistic regression model was built to assess the predictors of success. RESULTS: Overall success was 70%: 60% for main thoracic (MT) and 84% for main lumbar scoliosis (ML) (p = 0.003). Efficacy was 62% at Risser stage 0 and 78% at Risser stage 1–2 (p = 0.054). For MT, failure was associated with high in-brace sagittal C7 tilt (Odds Ratio = 0.72, p = 0.014) and low initial overcurve CA (Odds Ratio = 0.42, p = 0.044). For ML, a high standing height was associated with success (OR = 1.42, p = 0.035), and frontal unbalanced C7 tilt was associated with failure (OR = 0.43, p = 0.02). Conclusion: Twelve-hour nighttime CTM brace wear provided good results for main lumbar curves with balanced frontal C7 tilt. For MT, this treatment is indicated if the in-brace sagittal C7 tilt is well balanced from Risser stage 2.