The impact of immediate in-brace 3D corrections on curve evolution after two years of treatment: preliminary results.

For the brace treatment of adolescent idiopathic scoliosis (AIS), in-brace correction and brace-wear compliance are well-documented parameters associated with a greater chance of treatment success. However, the number of studies on the impact of sagittal and transverse correction on curve evolution in the context of bracing is limited. The objective of this work was to evaluate how immediate inbrace correction in the three anatomical planes is related to long-term curve evolution after two years of bracing. We performed a retrospective analysis on 94 AIS patients followed for a minimum of two years. We analyzed correlations between in-brace correction and two-year out-of-brace evolution for Cobb and apical axial rotations (ARs) in the medial thoracic and thoraco-lumbar/lumbar regions (MT & TL/L). We also studied the association between the braces' kyphosing and lordosing effect and the evolution of thoracic kyphosis (TK) and lumbar lordosis (LL) after two years. Finally, we separated the patients into three groups based on their curve progression results after two years (corrected, stable and progressed) and compared the 3D in-brace corrections and compliance for each group. Coefficients were statistically significant for all correlations. They were weak for Cobb angles (MT: -0.242; TL/L: -0.275), low for ARs (MT: -0.423; TL/L: -0.417) and moderate for sagittal curves (TK: 0.549; LL: 0.482). In-brace coronal correction was significantly higher in corrected vs stable patients (p=0.004) while compliance was significantly higher in stable vs progressed patients (p=0.026). This study highlights the importance of initial in-brace correction in all three planes for successful treatment outcomes.

Effectiveness of braces designed using computer-aided design and manufacturing (CAD/CAM) and finite element simulation compared to CAD/CAM only for the conservative treatment of adolescent idiopathic scoliosis: a prospective randomized controlled trial.

PURPOSE: Clinical assessment of immediate in-brace effect of braces designed using CAD/CAM and FEM vs. only CAD/CAM for conservative treatment of AIS, using a randomized blinded and controlled study design. METHODS: Forty AIS patients were prospectively recruited and randomized into two groups. For 19 patients (control group), the brace was designed using a scan of patient's torso and a conventional CAD/CAM approach (CtrlBrace). For the 21 other patients (test group), the brace was additionally designed using finite element modeling (FEM) and 3D reconstructions of spine, rib cage and pelvis (NewBrace). The NewBrace design was simulated and iteratively optimized to maximize the correction and minimize the contact surface and material. RESULTS: Both groups had comparable age, sex, weight, height, curve type and severity. Scoliosis Research Society standardized criteria for bracing were followed. Average Cobb angle prior to bracing was 27° and 28° for main thoracic (MT) and lumbar (L) curves, respectively, for the control group, while it was 33° and 28° for the test group. CtrlBraces reduced MT and L curves by 8° (29 %) and 10° (40 %), respectively, compared to 14° (43 %) and 13° (46 %) for NewBraces, which were simulated with a difference inferior to 5°. NewBraces were 50 % thinner and had 20 % less covering surface than CtrlBraces. CONCLUSION: Braces designed with CAD/CAM and 3D FEM simulation were more efficient and lighter than standard CAD/CAM TLSO's at first immediate in-brace evaluation. These results suggest that long-term effect of bracing in AIS may be improved using this new platform for brace fabrication. TRIAL REGISTRATION: NCT02285621.