German researchers have partnered with an international team under the EC-funded project Enhanced Durability Resurfacing Endoprosthesis (ENDURE) to develop a new hip implant designed to provide patients a metal-free solution and bone-like elasticity. Project partners include Aurora Medical, Medicoat, Hunt Developments, Ala Ortho, CeramTec, Invibio, Biomatech, and the Universities of Gothenburg and Southampton.

According to a news release from the Fraunhofer Institute for Manufacturing Engineering and Automation IPA, the implant’s socket is comprised of carbon fibre-reinforced PEEK. Researchers note that ceramic was used for femoral head and a hydroxylapatite coating at the interface to the bone was also added to ensure that the bone tissue fuse thoroughly with the surface structure of the implant. 

The ENDURE implants are reported be thin-walled shells which replace the bearing surface of the joint articulation alone, rather than using large metal stems for support. Researchers add that they used a press-fit and an integral scaffold-type structure on the surfaces of the implant that contact the bone. In this way, the hemispherical ball and socket are tapped onto the prepared femoral head and into the acetabulum, effectively anchoring it in place.

“Thanks to the new combination of materials, the transmission of force through the PEEK hip socket to the pelvic bone is modeled on natural conditions. And there are no metal ions released,” Jasmin Hipp, IPA engineer, explains.

The news release also reports that researchers have also developed a size-scalable tool to ensure optimal positioning of the implant. The disposable tool attaches the implant to standard surgical instruments and was created to enable implantation, re-alignment, and removal. Researchers say that preclinical studies of the implants have been completed and that further research work is being planned in order to allow the facilitation of clinical studies.

Source: Fraunhofer Institute for Manufacturing Engineering and Automation IPA