# Clinical Assessment of Customized 3D-Printed Wrist Orthoses
###### Abstract  
Paster casting has been effective in fracture rehabilitation due to its immobility capability. Thermoplastic casting gains some efficiency and convenience from clinical processing but fitting and immobility are two major tradeoffs. Three-dimensional (3D)-printed braces have demonstrated improvements in innovation, customization, and appearance, but one may question their effectiveness in rehabilitation. Via a science-based data-centric approach, we evaluated the feasibility of customizing 3D-printed braces for wrist fractures after surgery. First, we established a framework for determining a proper timeframe for reliable pressure measurement for plaster casts, devised a method to evaluate the immobilization capability of the plaster casts and customized braces, and assessed changes in immobilization capability due to the clearance adjustment of customized braces. Second, we compared the customized wrist braces and plaster casts in immobilization capability and functional effectiveness in clinical trials. Thirty-three patients were recruited (9, control; 24, experimental). Both the Disability of Arm, Shoulder, and Head, and the Manual Ability Measure surveys showed significant differences between the control and experimental groups after brace wearing time frames of 2, 4, 8, and 12 weeks, and 6 and 12 months. We found that customized braces can match plaster casts in immobilization ability and can promote effective functional recovery. c 20221221538 202211138 20221138 20221138 20221138 20221138 20221138 202211 20221138 20221138 20221138 20221138 20221138 20221138 20221138 202  
over the peri-sacral bony prominences of 980 seated subjects. The tolerance curve they produced confirmed an inverse relationship between the pressure and duration. This indicated that when allowing pressure across the time curve under 50 mmHg, it was possible to avoid complex decobitus syndrome [4]. [PERSON] et al. investigated the magnitude of pressure on the severity of injury and capillary closure in experimental pressure ulcers in rats. Between 60 and 70 mm Hg, repeated compressions for 4 h daily for 5 consecutive days resulted in partial skin necrosis and eschar formation in the majority of rats, whereas at 50 mmHg, skin injuries were absent or very mild in most of the rats [5]. Commercially available materials for wrist braces were innovated from traditional plaster to thermoplastic casts or splints, and materials were reshaped as fiberglass resin tape or splints. Fiberglass resin can be reshaped and has a shorter curing time than plaster or thermoplastic. However, these materials have similar issues after application: stuffiness, uncomfortable, not ventilated, and difficult to negotiate for dressing. Furthermore, most splints and casts using these materials can only be removed and replaced by professionals. Compared to the thermoplastic cast, the plaster cast achieves better immobility. Fitting and strength are the two main problems associated with using thermoplastic casts. Thanks to the rapid development of cutting-edge techniques in additive manufacture, also named rapid prototyping, people can turn their imagined creations into a physical reality. Instead of traditional subtractive molds manufacturing in a factory, additive manufacturing by 3D printers has become more and more popular. Due to easy access and easy use of the equipment and materials, one can easily produce 3D printer equipment at home. As 3D printing has become more mature and ubiquitous, designers armed with open source software have been able to produce braces, from design to final product, even in a home environment [6]. Patient-specific wrist orthoses fabricated by a 3D printer may perfectly fit the individual's wrist, unlike commercial orthoses. However, the cost of the materials, scanning, and manufacture time are much higher than that in mass production [7]. A hybrid design of 3D-printed wrist orthoses was designed to partially solve this by separating the plastic cast into an inner structure and an outer cover.