Prognostic model development for risk of curve progression in adolescent idiopathic scoliosis: a prospective cohort study of 127 patients.

BACKGROUND AND PURPOSE:  The study's purpose was to develop and internally validate a prognostic survival model exploring baseline variables for adolescent idiopathic scoliosis curve progression. METHODS:  A longitudinal prognostic cohort analysis was performed on trial data (n = 135) including girls and boys, Cobb angle 25-40°, aged 9-17 years, remaining growth > 1 year, and previously untreated. Prognostic outcome was defined as curve progression of Cobb angle of > 6° prior to skeletal maturity. 34 candidate prognostic variables were tested. Time-to-event was measured with 6-month intervals. Cox proportional hazards regression survival model (CoxPH) was used for model development and validation in comparison with machine learning models (66.6/33.3 train/test data set). The models were adjusted for treatment exposure. RESULTS:  The final primary prognostic model included 127 patients, predicting progress with acceptable discriminative ability (concordance = 0.79, 95% confidence interval [CI] 0.72-0.86). Significant prognostic risk factors were Risser stage of 0 (HR 4.6, CI 2.1-10.1, P < 0.001), larger major curve Cobb angle (HRstandardized 1.5, CI 1.1-2.0, P = 0.005), and higher score on patient-reported pictorial Spinal Appearance Questionnaire (pSAQ) (HRstandardized 1.4, CI 1.0-1.9, P = 0.04). Treatment exposure, entered as a covariate adjustment, contributed significantly to the final model (HR 3.1, CI 1.5-6.0, P = 0.001). Sensitivity analysis displayed that CoxPH maintained acceptable discriminative ability (AUC 0.79, CI 0.65-0.93) in comparison with machine learning algorithms. CONCLUSION:  The prognostic model (Risser stage, Cobb angle, pSAQ, and menarche) predicted curve progression of > 6° Cobb angle with acceptable discriminative ability. Adding patient report of the pSAQ may be of clinical importance for the prognosis of curve progression.

Nighttime Bracing or Exercise in Moderate-Grade Adolescent Idiopathic Scoliosis: A Randomized Clinical Trial.

Importance: Moderate-grade adolescent idiopathic scoliosis (AIS) may be treated with full-time bracing. For patients who reject full-time bracing, the effects of alternative, conservative interventions are unknown. Objective: To determine whether self-mediated physical activity combined with either nighttime bracing (NB) or scoliosis-specific exercise (SSE) is superior to a control of physical activity alone (PA) in preventing Cobb angle progression in moderate-grade AIS. Design, Setting, and Participants: The Conservative Treatment for Adolescent Idiopathic Scoliosis (CONTRAIS) randomized clinical trial was conducted from January 10, 2013, through October 23, 2018, in 6 public hospitals across Sweden. Male and female children and adolescents aged 9 to 17 years with an AIS primary curve Cobb angle of 25° to 40°, apex T7 or caudal, and skeletal immaturity based on estimated remaining growth of at least 1 year were included in the study. Dates of analysis were from October 25, 2021, to January 28, 2023. Interventions: Interventions included self-mediated physical activity in combination with either NB or SSE or PA (control). Patients with treatment failure were given the option to transition to a full-time brace until skeletal maturity. Main Outcomes and Measures: The primary outcome was curve progression of 6° or less (treatment success) or curve progression of more than 6° (treatment failure) seen on 2 consecutive posteroanterior standing radiographs compared with the inclusion radiograph before skeletal maturity. A secondary outcome of curve progression was the number of patients undergoing surgery up until 2 years after the primary outcome. Results: The CONTRAIS study included 135 patients (45 in each of the 3 groups) with a mean (SD) age of 12.7 (1.4) years; 111 (82%) were female. Treatment success was seen in 34 of 45 patients (76%) in the NB group and in 24 of 45 patients (53%) in the PA group (odds ratio [OR], 2.7; 95% CI, 1.1-6.6). The number needed to treat to prevent curve progression with NB was 4.5 (95% CI, 2.4-33.5). Treatment success occurred in 26 of 45 patients (58%) in the SSE group (OR for SE vs PA, 1.2; 95% CI, 0.5-2.8). Up to 2 years after the primary outcome time point, 9 patients in each of the 3 groups underwent surgery. Conclusions and Relevance: In this randomized clinical trial, treatment with NB prevented curve progression of more than 6° to a significantly higher extent than did PA, while SSE did not; in addition, allowing transition to full-time bracing after treatment failure resulted in similar surgical frequencies independent of initial treatment. These results suggest that NB may be an effective alternative intervention in patients rejecting full-time bracing. Trial Registration: ClinicalTrials.gov Identifier: NCT01761305.