Manufacturing research organisation IMR created a representative titanium spinal implant, aimed at the cervical spine, using nTopology’s generative design software. IMR then manufactured the implants using Renishaw’s RenAM 500M metal AM system.
“AM can be used to manufacture spinal implants with lattice structures, which cannot be achieved using conventional manufacturing techniques,” explains Ed Littlewood, marketing manager of Renishaw’s Medical and Dental Products Division. “An implant with a lattice structure is lightweight, can be optimised to meet the required loading conditions and has a greater surface area, which can aid osseointegration. Therefore, AM implants can be designed to mimic the mechanical properties of bone, resulting in better patient outcomes. But all of this comes to nothing if you do not have the tools to create the design.”
Matt Rohr, nTopology’s application engineering manager, adds: “Traditional CAD tools weren’t built to design complex lattice structures; the job would be difficult or even impossible. nTopology software was created to complement existing workflows and make the job easier. We cut the design time of complex structures from days to minutes, which was a crucial element in helping this project run to schedule.”
Says Sean McConnell, senior research engineer at IMR: “Renishaw worked tirelessly with us on improving the AM process for producing the spinal implants. Together, we designed a set of experiments that helped yield the most appropriate parameter settings for the product. As a result, we reduced the amount of post-processing required on key features of the implants by a factor of 10.”
Patients with medical conditions that include degenerative disc disease, herniated disc, spondylolisthesis, spinal stenosis and osteoporosis, can require spinal implants to restore intervertebral height. The improved implant design made possible by AM means patients may require shorter surgery time and fewer revision surgeries, saving healthcare resources and costs.
Renishaw also uses its AM machines to produce healthcare products such as craniomaxillofacial implants and dental frameworks, at its site in Miskin, Wales.