AIMing for the future of medical implants with EBM technology

AIM Sweden was founded as a commercial spin-off from the Mid Sweden University, in the town of Östersund. “We are a subcontractor producing orthopedic implants, but we are also an engineering partner. We do a lot of engineering work together with the customers even if we don’t own the product design because we are working for the OEM,” says Marie Cronskär, Orthopedic Applications Director.

The research group at the university, from where the company was born, were early advanced users of the EBM technology (a commonly used technology for medical implants) – focusing both on process development, looking at new materials, and also doing work on patient-specific implants (the focus of Marie’s Ph.D.). In 2015, the group decided to create a commercial company, and in early 2016, the company was founded and received its first machines.

In the last couple of years, the company narrowed its focus down to two main market segments – molded fiber and orthopedics – the latter of which is currently the biggest in terms of revenue. “We anticipate though, that the molded fiber business segment has the potential to outgrow the orthopedic business, even if the orthopedic market is a very healthy and growing market,” says Stefan Thundal, CEO of AIM Sweden, who joined the company after a decade spent at Arcam, the Swedish company, now part of GE Additive, that first developed and commercialized the EBM technology. “The adoption of 3D printing is growing also in that market segment, so we see that we have great opportunities there as well.”

An EBM-focused production partner

In terms of positioning, AIM Sweden considers itself as an engineering partner and expert in EBM printing. “We have a lot of experience and knowledge about the EBM process and how to set up and run builds to achieve robust and cost-efficient production. Additionally, we also have a lot of experience in the quality aspects and the validation of the production process. As this is still a relatively new way to produce implants, some [clients] need help around that aspect as well. I would say this is our strength,” Marie tells VoxelMatters. “And also, of course, often the driver for using 3D printing is lattice structures for bone in-growth. This is an area where we often support customers to generate the lattice they need and design new types of lattices. We have a lot of knowledge in this area that enables us to support clients that want a new design of a lattice and don’t have that capability in-house.”

AIM Sweden mostly produces standard implants in serial production, but also occasionally produces patient-specific implants as well. Last year, the company produced 14,000 implants, using two Q10 Plus machines running more or less continuously.

With reference to large implant OEMs, such as Stryker and Zimmer Biomet (the largest manufacturers of orthopedic implants and noteworthy adopters of AM technology), AIM Sweden does not see them as competition, but rather as potential clients. In some cases, the company has partnered with OEMs, with their own in-house AM capability, as a second source of production to their own in-house capacity. This successful approach has previously led to AIM Sweden becoming the primary production source for some of the products.

Although AIM Sweden generally works with orthopedic OEMs, the company has also worked directly with hospitals to deliver patient-specific implants, cutting/drilling guides, or pre-operative models used for surgery planning.

Optimizing AM to suit market demands

Currently, AIM Sweden mostly produces joint replacement implants for primary surgery of hips and knees, such as hip cups and hip stems, but AIM Sweden also produces implants used for revision surgeries. “Sometimes revision surgeries are needed and then you use certain implants to fill out where you have bone loss,” Marie explains.

“A big segment that we are getting into more, and think will grow, is spinal implants. The adoption of AM technology in this area is growing and it is something we intend to work with a lot. Spinal implants suit our technology very well as we can stack large quantities of parts in every build, using the EBM technology. We see that we can be very cost-efficient on those types of small implants.”

“The most common driver for choosing 3D printing for production of implants is first to open up for greater design freedom for innovative porous structures for bone in-growth and secondly to efficiently produce these implants. Customization is another driver that is becoming more common, but still the most common driver is is that you choose 3D printing as it is an efficient way to produce implants with a porous structure, so-called press-fit implants” Stefan adds.

The alternative approach to press-fit implants has historically been cemented implants,  which are fixated on the body with bone cement. Cemented implants are still common for certain surgeries, like knee surgeries, but that is about to change. “There is a strong upward trend in the use of press-fit knee implants, and that, of course, opens up an even bigger potential market for us, as a 3D printing company.”

When asked about how AIM Sweden operates, from the perspective of the client, Marie says, “Sometimes they come with the final product that is already on the market, and they just want a second production source. Then for us, it’s about defining a proper build setup (the file preparation, the support structure, the post-processing, etc) and then printing it efficiently and with high quality. But it can also be that they have new products or new product ideas, where we can be part of the design process from the beginning. This is where we want to be because this way we can implement small changes that can make it so much easier, both to print and to post-process, because often the customers don’t have that knowledge.”

“One common challenge with 3D printed raw products is that, when you bring them to the machining shop, you don’t have any obvious fixed reference points. So, you need to position and align the components in the right way to do the machining properly and this is not always easy. By designing the raw part that we print in a smart way, you can make that easier. So, this is a fundamental aspect of our work, to keep focused on – not only the printing step but on the entire manufacturing process,” Stefan concludes