Patient-specific implants made of 3D printed bioresorbable polymers at the point-of-care: material, technology, and scope of surgical application

Michaela Maintz; Céline Tourbier; Michael de Wild; Philippe C Cattin; Michel Beyer; Daniel Seiler; Philipp Honigmann; Neha Sharma; Florian M Thieringer

doi:10.1186/s41205-024-00207-0

Patient-specific implants made of 3D printed bioresorbable polymers at the point-of-care: material, technology, and scope of surgical application

3D Print Med. 2024 Apr 19;10(1):13. doi: 10.1186/s41205-024-00207-0.

Authors

Michaela Maintz^#^{1

2

3}, Céline Tourbier^#^{4

5}, Michael de Wild³, Philippe C Cattin⁶, Michel Beyer^{1

2}, Daniel Seiler³, Philipp Honigmann^{2

7

8}, Neha Sharma^#^{1

2}, Florian M Thieringer^#^{1

2}

Affiliations

¹ Oral and Cranio-Maxillofacial Surgery, University Hospital Basel, Spitalstrasse 21, Basel, Switzerland.
² Department of Biomedical Engineering, Medical Additive Manufacturing Research Group (Swiss MAM), University of Basel, Hegenheimermattweg 167C, Allschwil, Switzerland.
³ Institute for Medical Engineering and Medical Informatics IM², University of Applied Sciences and Arts Northwestern Switzerland FHNW, Hofackerstrasse 30, Muttenz, Switzerland.
⁴ Oral and Cranio-Maxillofacial Surgery, University Hospital Basel, Spitalstrasse 21, Basel, Switzerland. celine.tourbier@usb.ch.
⁵ Department of Biomedical Engineering, Medical Additive Manufacturing Research Group (Swiss MAM), University of Basel, Hegenheimermattweg 167C, Allschwil, Switzerland. celine.tourbier@usb.ch.
⁶ Department of Biomedical Engineering, Center of Medical Image Analysis and Navigation (CIAN), University of Basel, Hegenheimermattweg 167C, Allschwil, Basel, Switzerland.
⁷ Department of Orthopaedic Surgery and Traumatology, Hand- and peripheral Nerve Surgery, Kantonsspital Baselland, Bruderholz| Liestal| Laufen, Switzerland.
⁸ Biomedical Engineering and Physics, Amsterdam UMC location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.

^# Contributed equally.

Abstract

Background: Bioresorbable patient-specific additive-manufactured bone grafts, meshes, and plates are emerging as a promising alternative that can overcome the challenges associated with conventional off-the-shelf implants. The fabrication of patient-specific implants (PSIs) directly at the point-of-care (POC), such as hospitals, clinics, and surgical centers, allows for more flexible, faster, and more efficient processes, reducing the need for outsourcing to external manufacturers. We want to emphasize the potential advantages of producing bioresorbable polymer implants for cranio-maxillofacial surgery at the POC by highlighting its surgical applications, benefits, and limitations.

Methods: This study describes the workflow of designing and fabricating degradable polymeric PSIs using three-dimensional (3D) printing technology. The cortical bone was segmented from the patient's computed tomography data using Materialise Mimics software, and the PSIs were designed created using Geomagic Freeform and nTopology software. The implants were finally printed via Arburg Plastic Freeforming (APF) of medical-grade poly (L-lactide-co-D, L-lactide) with 30% β-tricalcium phosphate and evaluated for fit.

Results: 3D printed implants using APF technology showed surfaces with highly uniform and well-connected droplets with minimal gap formation between the printed paths. For the plates and meshes, a wall thickness down to 0.8 mm could be achieved. In this study, we successfully printed plates for osteosynthesis, implants for orbital floor fractures, meshes for alveolar bone regeneration, and bone scaffolds with interconnected channels.

Conclusions: This study shows the feasibility of using 3D printing to create degradable polymeric PSIs seamlessly integrated into virtual surgical planning workflows. Implementing POC 3D printing of biodegradable PSI can potentially improve therapeutic outcomes, but regulatory compliance must be addressed.

Keywords: 3D Printing; Bone; Composites; Computer-aided design; Defect; Hospital; Lattice; Osteosynthesis; Point-of-care; Polymers; Regeneration; Three-dimensional.