Identifying Risk Factors Associated with Providence Bracing Failure: Demographic and Radiographic Characteristics

The Providence brace (PNB) is common treatment in mild to moderate scoliosis. However, limited literature describes radiographic variables linked to PNB failure. This study aimed to investigate factors associated with failed PNB treatment, particularly demographic and radiographic characteristics. A retrospective cohort study was performed on idiopathic scoliosis patients treated with the PNB from 2012-2024 at a single institution. Eligible individuals were 7-17 years old, Risser stage 0-2, with an initial Cobb angle of 15-40°and were premenarchal or ≤1-year postmenarchal. Patients with prior treatment, trauma, non-idiopathic scoliosis, and cervical/cervicothoracic curves were excluded. Treatment failure was defined as ≥6° curve progression, total curve magnitude ≥45°, recommended surgery, brace-type switching, or non-compliance. Statistical analyses included descriptive statistics and unpaired t-tests. A total of 158 patients were analyzed as PNB treatment failures (35.44%) and treatment successes (64.66%). Mean patient age was 11.28 years, with an average initial Risser score of 0.36, and an initial out-of-brace (OOB) Cobb angle of 24.46°. Mean follow-up was 33.47 months. PNB failure was due to curve progression ≥6° (55%), total curve magnitude ≥45° (14%), brace-type switching (28%), and recommended surgery (13%). Initial, 6-month, 1-year, 2-year, and final OOB Cobb angles were significantly greater in patients who failed treatment (all p<0.05). PNB failures also had greater initial maximum apical vertebral rotation (AVR) (0.57 vs. 0.15, p<0.001) and reported significantly fewer hours of nightly brace wear (4.78 vs. 7.91, p<0.001). PNB outcomes are multifactorial. Greater initial OOB Cobb angle, higher initial AVR and fewer hours of bracing were associated with failure.