SureMAX Cervical Spacer, lordotic and hyperlordotic options. Image courtesy of Additive Implants Inc.
As one might expect from Additive Implants Inc.’s name, 3D printing is critical to the company’s mission. The company’s founder, an orthopedic spine surgeon, was frustrated at the available cervical spacer options for anterior cervical discectomy and fusion (ACDF) surgery, so he decided to develop his own, turning to additive manufacturing technologies for both prototyping and production.
“The whole concept is to take advantage of designs and geometries that could not be cost effectively produced using CNC machining techniques,” Jeff Horn, VP Commercialization for Additive Implants, told MD+DI. “Our founder's first goal was to provide his patients with the best possible clinical outcome. He [has] so much clinical experience, he knows which implant designs work and do not work. As a company, we are always looking for ways to address unmet surgeon needs. We want to solve those clinical problems as economically as possible and provide the surgeon with instruments and implants that make the procedures reproducible, safe and simple so that excellent outcomes are reproducible.”
The company just announced the FDA clearance of its first product. The SureMAX Cervical Spacer employs a 3D-printed titanium alloy. “Failure to achieve sagittal alignment due to hardware design limitations still exists in ACDF procedures,” explained Bob Brosnahan, COO with Additive Implants, in a news release. “We’ve learned through extensive research with high volume cervical surgeons that stability at the bone-implant interface, throughout the healing process, may hold the key to better sagittal alignment and improved clinical outcomes. The SureMAX Cervical Spacer was engineered with that type of stability in mind.”
“3D printing has enabled us to develop a cervical spacer with roughened porous surfaces and several unique features on the superior, inferior, and lateral aspects that improve the stability of the implant bone interface” the company explained in the release. “These features combine to provide an ideal environment for fusion.”
“3D printing also allows for production of more unique and complicated designs on a smaller scale than traditional CNC Machining,” added Horn. “CNC machining and additive manufacturing [each] have their strengths and weaknesses. CNC machining is appropriate when you need large, stronger parts. Given that our spacers are smaller in diameter than a nickel, 3D printing was better suited to give us the design flexibility that we needed. 3D printing is also more economical than CNC machining as there is little or no wasted material.”
The company has also found 3D printing to be “incredibly collaborative—simple yet complicated,” Horn said. “Our surgeons have very specific design elements and features in mind for the product and the benefits they provide clinically. Their product idea is then modeled in CAD and sent to the 3D-printed part manufacturer who reviews and makes suggestions—this angle is too sharp, this wall is too thin, too thick, we can't support that structure, etc. We go back to the drawing board, make the changes, and the part goes back through our FEA to see if it meets our performance specs.”
Horn said “this dance goes on and on until both parties are finally satisfied. Then a number of parts are created and sent for what we call a ‘reality check’. If they pass actual mechanical testing, then we are ready to go to production. If not, we go back to the drawing board. We may go through several of these iterations to get the part the way we both want it. In order to ensure that our prototypes and commercial products are identical, we produce them both on the same machines, using the same material."
Additive Implants isn’t developing personalized devices for individual patients—however, it isn’t taking a one-size-fits all approach, either. “We have created a family of sizes that we believe will address a wide range of anatomies and pathologies,” Horn said.
Additive Implants launched the SureMAX Cervical Spacer System at the annual meeting of the AANS/CNS Section on Disorders of the Spine and Peripheral Nerves Spine Summit 2019 in March.
Another cervical spacer with what Horn describes as some “very unique, patent pending design features” is set to be launched in the fourth quarter this year. “We also have several lumber products in the pipeline with expected release the first half of 2020,” he said.