Patient-specific Biodegradable Implants: The Future of Surgery?

Reconstruction of a Human Scaphoid Bone

The replacement of bones in course of accident treatment usually requires titanium implants. It is a widely used material for trauma surgery but shows inherent drawbacks: A mismatch of mechanical properties, interface issues to the surrounding soft tissues and no capability to grow.

 

A joint research project of GeSiM and Dresden University of Technology (TU Dresden) – Centre for Translational Bone, Joint and Soft Tissue Research – aimed in establishing 3D printing of patient-specific implants of a degradable biomaterial. As model the human scaphoid bone was selected and 3D data extracted from a CT scan.

 

1a) CT data set of human hand

1a) CT data set of human hand

1d) 3D model of scaphoid bone

1d) 3D model of scaphoid bone

1c) Segmentation of the scaphoid bone

1c) Segmentation of the scaphoid bone

1b) Bone extraction

1b) Bone extraction

 

 

In a first step the CT data of the patient were analysed to separate bones from the remaining tissue (Virtual environment/ contouring). Next the CT data was transformed into a 3D DICOM model using an Open Source software package. The scaphoid bone was isolated from the complete bone set to generate 3D STL data, a format describing surfaces by triangularization. The STL format is widely used by all kind of 3D printers, also the GeSiM BS3.1.

 

2) Scaphoid bone printed from bone cement [1], [2]

2) Scaphoid bone printed from bone cement [1], [2]

Finally the STL data of the scaphoid bone was loaded into the software of the GeSiM BS3.1. The bone model was printed from calcium phosphate bone cement VELOX® from InnoTERE GmbH, Radebeul.

 

This work is a research project without clinical background. Future research may be focusing on the settlement of osteoblasts or mesenchymal stem cells in the scaffold structure for subsequent incubation and generation of an artificial “living” bone.

 

We thank the BMWi for funding this work (AiF-ZIM program, project number KF2891602).


[1] T. Ahlfeld et al., Centre for Translational Bone, Joint and Soft Tissue Research, Technical University Dresden

 

[2] M. Heller, H.-K. Bauer, E. Goetze, M. Gielisch, I. T. Ozbolat, K. K. Moncal, E. Rizk, H. Seitz, M. Gelinsky, H. C. Schröder, X. H. Wang, W.E.G. Müller, B. Al-Nawas: Materials and Scaffolds in Medical 3D Printing and Bioprinting in the Context of Bone Regeneration. Int. J. Computerized Dent. 2016, 19, 301-321 (Figure 6)