Tuesday, 22 February 2011

First use of laser-sintered PEEK for craniofacial implants

This customised craniofacial PEEK implant has a scaffolding mesh that can only be created by laser-sintering. The mesh promotes improved bone growth after implantation.
The first PEEK craniofacial test implants to be produced by the laser-sintering additive manufacturing process have been presented by EOS at the co-located Pacific Design & Manufacturing/MD&M (Medical Design & Manufacturing) West shows at the Anaheim Convention Center, California, USA.

EOS’ Collaborative Projects Coordinator, Joerg Lenz, delivered a previously unpublished technical paper on results from a European Union-funded project called Custom-IMD. Core project activities include the development of new biomaterials and rapid manufacturing technologies that will allow customised implants to be delivered to surgeons within a 48 hour time frame.

Entitled “Laser Sintering of PEEK", Lenz's paper described plastic test implants fabricated at EOS' headquarters in Germany using the EOSINT P 800 system, the first laser-sintering system capable of operating at up to 385 degrees C for processing high-performance polymers.

High-temperature, biocompatible PEEK (polyaryletherketone) is increasingly used as an alternative to titanium for craniofacial implants, which are produced from CT-scan geometry for patients with head injuries or congenital deformities. The paper documented the first validated in vivo (animal) results for laser-sintered PEEK.

“Conventional manufacturing technologies are not able to produce patient-customised craniofacial implants, either titanium or PEEK, as economically or in as short a time span as laser-sintering,” said Lenz.

“What is more, EOS technology has enabled us to develop a specific geometry that can only be achieved using additive manufacturing. The new design incorporates a mesh scaffold that promotes improved bone growth and optimises infiltration with a hydroxyapatite-filled, bio-absorbable polymer.”

Implants displayed on the EOS stand at the show included one filled with the polymer.

Lenz serves on a number of international standardisation organisations, including ASTM Committee F42 on additive manufacturing technologies. PEEK-implant animal studies continue through the EU-funded project and human trials are planned for the future.

The implant pictured was designed by a team at AZM (the University Hospital Maastricht, The Netherlands) headed by Dr Jules Poukens. A patent for the network of holes in the mesh scaffold has been applied for.

Scott Killian of Royal Engineered Composites, the first American user of the P 800, was on the EOS stand to discuss his company’s use of the machine and show sample geometries of PEEK medical and aerospace parts. There was a working FORMIGA P 100 laser-sintering system as well as metal parts produced with direct metal laser-sintering (DMLS).

EOS Electro Optical Systems Ltd