The role of 3-dimensional printed models in the management of the distal radius fractures.

Objective: This study aimed to compare inter- and intra-observer agreement between radiographs with 2-dimensional and 3-dimensional computed tomography scans with and without 3-dimensional printed models in the evaluation of the distal radius fracture of Association for Osteo synth esis/ Ortho paedi c Trauma Association type C classification.

Methods: Fifteen consecutive cases with X-Rays, 2-dimensional and 3-dimensional computed tomography reconstructions views, and 3-dimensional printed models were selected. Three-dimensional printed models of the distal radius fractures were created using 2-dimensional computed tomography scan files in Digital Imaging and Communication in Medicine format, processed with the 3-dimensional Slicer software, and segmented, creating a 3-dimensional printed model in Standard Triangle Language format. Threedimensional models were printed using fused deposition modeling (FDM) type 3D printer Zortrax M200Plus using polylactic acid material on a scale of 1 : 1. Twenty observers were invited into the study.

Results: Intra- and inter-observer reliability was analyzed using Fleiss' kappa statistics. Overall kappa values for both groups in interobserver agreement range from 0.113 to 0.283 and in intra-observer agreement from 0.25 to 0.545. Generally, inter-observer agreement increased with additional 3-dimensional printed models from slight to fair, and intra-observer agreement increased from fair to moderate. Surgeons' opinions about 3-dimensional printed models with Likert scale-type questions show positive overall results ranging from 8.3± 2.1 to 8.6 ± 1.4.

Conclusion: This study has shown that the inter- and intra-observer agreement with the addition of a 3-dimensional printed model for the evaluation of the distal radius fractures of Association For Osteo synth esis/ Ortho pedic Trauma Association C type for classification, fractures morphology, and preoperative planning tends to increase; however, improvements for an inter-observer agreement remain fair.

Level of evidence: Level III Diagnostic Study.