Dimensional Accuracy of 3D-printed Models of the Right First Metacarpal Bones of Cadavers

Abstract

Background. The use of 3D printing in medical education, prosthetics, and preoperative planning requires
dimensional accuracy of the models compared to the replicated tissues or organs.
Objective. To determine the dimensional accuracy of 3D-printed models replicated from metacarpal bones from
cadavers.

Methods. Fifty-two models were 3D-printed using fused deposition modeling (FDM), stereolithography (SLA),
digital light processing (DLP), and binder jetting method from 13 right first metacarpal bones of cadavers from
the College of Medicine, University of the Philippines Manila. Six dimensional parameters of the 3D-printed
models and their control bones were measured using 0.01 mm calipers — length, midshaft diameter, base width,
base height, head width, and head height. Mean measurements were compared using non-inferiority testing and
multidimensional scaling.

Results. Mean measurements of the 3D-printed models were slightly larger than their control bones (standard
deviation range: 1.219-4.264; standard error range, 0.338-1.183). All models were found to be at least 90% accurate
and statistically non-inferior compared to control bones. DLP-printed models were the most accurate (base width,
99.62 %) and most similar to their control bone (–0.05, 90% CI –0.34, 0.24). Through multidimensional scaling,
DLP-printed models (coordinate = 0.437) were the most similar to the control bone (coordinate = 0.899).

Conclusion. The 3D-printed models are dimensionally accurate when compared to bones.