Reconceiving orthopaedic spinal braces for spinal muscular atrophy treatment: A digital modeling and 3D printing combined framework.

Objective: Spinal Muscular Atrophy (SMA) Type 2 is a genetic neuromuscular disorder characterized by progressive muscle weakness and spinal deformities, often requiring the use of spinal braces for postural support. Traditional braces are typically rigid, uncomfortable, and time-consuming to manufacture, limiting their adaptability to patient-specific needs. This study aims to develop a novel, patient-centred framework for designing and fabricating custom spinal braces using digital tools and additive manufacturing (AM). Methods: the proposed framework combines spine data acquisition, computational modeling for structural optimization, and AM through fused filament fabrication (FFF). The brace design integrates advanced lattice geometries-including triply periodic minimal surfaces (TPMS) and auxetic kirigami patterns-to enhance ventilation, reduce weight, and increase flexibility without compromising mechanical stability. A prototype brace was fabricated using polypropylene (PP) for rigid structural elements and thermoplastic polyurethane (TPU) for flexible inserts to ensure both support and comfort. Results: the resulting prototype demonstrated significant improvements in terms of production efficiency, customization, and user comfort. The use of AM enabled a reduction in manufacturing time and facilitated the integration of complex geometries tailored to the patient's anatomy. The brace offered enhanced breathability and flexibility, contributing to improved wearability and patient compliance compared to conventional designs. Conclusions: this approach represents a step forward in orthopaedic treatment, offering a more adaptive, cost-effective, and patient-centred solution for managing SMA-related spinal deformities.