Effectiveness of Orthotic Treatment on Clinical Outcomes of the Patients with Adolescent Idiopathic Scoliosis Under Different Wearing Compliance Levels

Background: Wearing spinal orthosis for 16 to 23 hours a day during the teenage years could be challenging and stressful for patients with adolescent idiopathic scoliosis (AIS). The investigation of clinical outcomes under various orthosis-wearing compliances can provide helpful insight into orthotic treatment dosage. This systematic review aims to investigate actual orthosis-wearing compliance and evaluate the effectiveness of orthotic treatment in controlling scoliotic curvature and preventing surgery for patients with AIS under various levels of orthosis-wearing compliance. Methods: A literature search of 7 electronic databases, namely PubMed, MEDLINE, Cochrane Library, Scopus, CINAHL Complete, Web of Science, and Embase, was conducted on May 19, 2023. Participant characteristics, orthotic treatment protocols, compliance information, outcome measures, and key findings were extracted. The Newcastle-Ottawa Scales were used to evaluate the quality of included cohort and case-control studies. Results: This study systematically reviewed 17 of 1,799 identified studies, including 1,981 subjects. The actual compliance was inconsistent and ranged from 7.0 to 18.8 hours daily. The proportion of compliant subjects in each study varied from 16.0% to 78.6% due to the heterogeneity of calculation period, measurement methods, and orthosis prescription time. Thirteen studies were investigated to determine the effectiveness of orthotic treatment in controlling curve deformity under different compliance groups, and 2 studies compared the compliance under different treatment outcomes. The rate of curve progression, defined as surpassing the measurement error threshold of 5° or 6° after orthotic treatment, varied from 1.8% to 91.7% across the studies. Ten studies defined the treatment failure, surgery, or surgery indication as Cobb angle progressing to a certain degree (e.g., 40°, 45°, or 50°) and reported failure/surgery/surgery indication rates ranging from 0.0% to 91.7% among different compliance level groups. Conclusion: This review found that the actual compliance with orthotic treatment was generally lower than the prescribed wearing time and exhibited wide variation among different studies. The electronic compliance monitors show promise in regular orthotic treatment practice. More importantly, the group with higher and consistent compliance has significantly less curve progression and lower surgery or failure rate than the group with lower and inconsistent compliance. Further studies are proposed to investigate the minimal orthosis-wearing compliance in patients with AIS treated with different types of orthoses. Level of Evidence: Level III , Systematic Review. See Instructions for Authors for a complete description of levels of evidence.