Geometric accuracy of an acrylonitrile butadiene styrene canine tibia model fabricated using fused deposition modelling and the effects of hydrogen peroxide gas plasma sterilisation

Abstract

Background

Three-dimensional (3D) printing techniques have been used to produce anatomical models and surgical guiding instruments in orthopaedic surgery. The geometric accuracy of the 3D printed replica may affect surgical planning. This study assessed the geometric accuracy of an acrylonitrile butadiene styrene (ABS) canine tibia model printed using fused deposition modelling (FDM) and evaluated its morphological change after hydrogen peroxide (H₂O₂) gas plasma sterilisation. The tibias of six canine cadavers underwent computed tomography for 3D reconstruction. Tibia models were fabricated from ABS on a 3D printer through FDM. Reverse-engineering technology was used to compare morphological errors (root mean square; RMS) between the 3D-FDM models and virtual models segmented from original tibia images (3D-CT) and between the models sterilised with H₂O₂ gas plasma (3D-GAS) and 3D-FDM models on tibia surface and in cross-sections at: 5, 15, 25, 50, 75, 85, and 95% of the tibia length.

Results

The RMS mean ± standard deviation and average positive and negative deviation values for all specimens in E_FDM-CT (3D-FDM vs. 3D-CT) were significantly higher than those in E_GAS-FDM (3D-GAS vs. 3D-FDM; P < 0.0001). Mean RMS values for E_FDM-CT at 5% bone length (proximal tibia) were significantly higher than those at the other six cross-sections (P < 0.0001). Mean RMS differences for E_GAS-FDM at all seven cross-sections were nonsignificant.

Conclusions

The tibia models fabricated on an FDM printer had high geometric accuracy with a low RMS value. The surface deviation in E_FDM-CT indicated that larger errors occurred during manufacturing than during sterilisation. Therefore, the model may be used for surgical rehearsal and further clinically relevant applications in bone surgery.