Design and Preliminary Phantom Study of a 3D-Printed Wrist Immobilization Device for Lateral Radiography.

Background/

Objectives

Distal radius and carpal fractures are common injuries in emergency radiology, where accurate lateral wrist positioning is essential for diagnostic image quality. Maintaining a true lateral position can be challenging, often requiring manual support and increasing occupational radiation exposure. This pilot phantom study aimed to design, fabricate, and evaluate a novel 3D-printed wrist immobilization device and compare its performance with adhesive tape and sandbag stabilization.

Methods

A wrist immobilization device was designed using computer-aided design software and fabricated by fused deposition modeling with polylactic acid. A wrist phantom was imaged using three stabilization techniques: the 3D-printed device, adhesive tape, and sandbag support. Image quality was independently assessed by two blinded observers using an eight-point scoring system. Inter-rater reliability was evaluated using the intraclass correlation coefficient (ICC). Positioning time was recorded, and radiopacity was assessed using pixel intensity measurements within predefined regions of interest.

Results

No significant differences in image quality were observed among the three stabilization techniques (p = 0.263). Inter-rater reliability was excellent (ICC = 0.877). Positioning time differed significantly among techniques (p = 0.036), with sandbag stabilization requiring the shortest time. Radiopacity analysis demonstrated minimal attenuation (8.6-20.8%) in regions adjacent to the anatomical area of interest, while higher attenuation was limited to non-diagnostic regions.

Conclusions

The 3D-printed wrist immobilization device produced image quality comparable to conventional stabilization methods with minimal radiographic interference. These findings support its feasibility as a low-cost positioning aid and warrant further evaluation in larger clinical studies.