Design and application of a three-dimensional skeletonized structure for distal radius fracture splinting based on 3D printing technology

Distal radius fractures (DRFs) are among the most commonly encountered types of fractures in clinical practice. Conventional treatment methods include surgical intervention and traditional small splint fixation following manual reduction based on Traditional Chinese Medicine (TCM). However, these conventional small splints do not adequately meet the current demands for personalized and precision medicine. To address this issue, this study proposes a novel personalized distal radius fixation splint utilizing 3D printing technology. Firstly, a customized splint model that conforms to the patient's fracture surface is established through three-dimensional scanning of the fracture site. Subsequently, the Tyson polygon structure and Grasshopper software are employed to parameterize the hollowing-out process of the splint, resulting in a personalized splint with a three-dimensional hollow-out structure. During the static analysis of the 3D hollow splint model, forces of 100 N and 150 N were applied. Under a force of 100 N, the maximum deformation of the splint was measured at 0.52 mm with a maximum strain value of 0.02 mm/mm and a maximum equivalent stress level of 19.415 MPa. However, when subjected to a force of 150 N, the maximum deformation increased to 0.78 mm with a corresponding increase in maximum strain value to 0.03 mm/mm and an elevated maximum equivalent stress level measuring 29.122 MPa. Additionally, this study also examined the flexural strength and weight of the 3D-printed splint in comparison to the conventional small splint. The test results demonstrate that, under pressure of 150 N, the radial offset of the 3D printed splint is reduced by 1.7 mm compared to that of the traditional small splint, with a corresponding decrease in stress by 0.01 MPa as well. In terms of weight, a set of 3D printed splints weighs 89 g while a set of conventional splints weighs 102 g, resulting in a significant reduction of 13 g for the 3D printed splints compared to their traditional counterparts. These findings indicate clear advantages associated with utilizing 3D-printed splints in terms of minimizing offset and reducing overall weight.