Comparative Accuracy Assessment of Thoraco-Lumbo-Sacral Orthosis Fabrication: Conventional Contact Casting Versus Noncontact 3-Dimensional Digital Scanning

Objective: Contact casting with plaster bandages is a standard technique for thoraco-lumbo-sacral orthosis (TLSO) fabrication. However, this hands-on process depends on the operator's skill as well as requires a close physical contact, involving potential risks of coronavirus and influenza virus infection and the patient's personal space violation. Recently, noncontact, highly accurate molding technology using 3-dimensional (3D) digital scanning has been developed. Although 3D scanning is widely applied for limb orthosis, its spinal application mainly focuses on pediatric scoliosis. Comparative studies across diverse body types remain limited. Therefore, this study aimed to clarify the adaptability, accuracy, and fabrication time of TLSO produced using noncontact 3D digital scanning, comparing with conventional contact plaster-bandage casting. Methods: TLSO was fabricated using both contact and noncontact techniques for mannequins with 4 different body types. High-precision scanner and computed tomography (CT) were used to assess the shape reproducibility by quantifying the gap area between the orthosis and mannequin. In addition, total fabrication time was compared between the 2 techniques. Results: High-precision scanner identified that 3D scanning showed a higher shape reproducibility than conventional casting, particularly in curvilinear areas (all p<0.001). In CT measurement, 3D scanning demonstrated a smaller gap area in all the body types (all p<0.001). Fabrication time was also shorter during 3D scanning (54.9±0.9 minutes) than during conventional casting (100.0±5.5 minutes) (p<0.001). Conclusion: Noncontact 3D digital scanning facilitates a rapid, accurate, and reproducible TLSO fabrication across diverse body types, providing a safer and more efficient alternative to conventional contact plaster-bandage casting.