3D Printing Is Ready To Tackle Plastic Body Implants

After an accident left a 40-year-old woman in Sweden with a massive head injury late last year, she received a 3D-printed implant made from a plastic called PEEK to repair her skull.

It was the first time a hospital had designed and 3D printed an implant of this kind on-site, and it could prove a turning point for 3D printing in medical care.

“As far as we know, we are the world’s first to make 3D implants entirely in a hospital, which means that the implants will be better adapted to the patients, right from the start,” says Einar Heiberg Brandt, medical engineer in Clinical Physiology at Skåne University Hospital, Sweden. “This will lead to faster surgeries and fewer complications.”

In-hospital 3D printing is still in the early stages, but shows great promise, industry experts agree. Although 3D printing has been used in healthcare for more than a decade to manufacture titanium and stainless steel implants, PEEK plastic expands opportunities for the technology to move off the shop floors of medical device manufacturers and into labs at hospitals and clinics worldwide.

In fact, medical facilities represent a vast new market for 3D printing. The healthcare segment of the 3D printing industry, which includes dental and 3D-printed pharmaceuticals, currently is valued at nearly $3 billion.

3D Printing at Hospitals

Institutions, such as the Mayo Clinic in Minn. and VA hospitals nationwide, have extensive 3D printing labs. The work there is mostly patient-specific 3D-printed medical models, surgical training tools, and orthopedic braces. However, in the not too distant future, these hospitals may be 3D printing patient-specific implants in PEEK for all types of surgeries.

Using a 3D printer and PEEK filament brings a long list of benefits to hospitals, while still having substantial hurdles. The method, when compared to traditional ways medical devices are made, namely machining and injection molding, can be done on-site at the point of care. This means faster implants, lower costs, and closer coordination between the surgeon and the technicians producing the implant.

By using the patient’s data from scans and X-rays, hospitals can 3D print a custom implant that fits precisely into the defect space.

Studies show that patient-specific implants shorten surgery time, lower risks of infection, result in better outcomes, and dramatically reduce the length of a hospital stay. 3D printing the implants as needed also relieves the hospital from having to keep an inventory of expensive implants on hand.

Although, as of today, there are no 3D-printed PEEK implants manufactured at hospitals approved by the FDA, that may soon change.

A German start-up specializing in 3D-printed PEEK skull implants, Kumovis, says it’s completing the final hurdles in the FDA approval process.

“There’s a lot of excitement around 3D printing on-site at hospitals and the projects that are driving manufacturing at the point of care and showing what is possible,” says Miriam Haerst, co-founder and co-CEO of Kumovis.

South Carolina-based 3D Systems, one of the oldest and largest 3D printer manufacturers in the world, recently announced its plans to acquire Kumovis in order to expand from metal implants to PEEK implants at the point of care.

“As [3D printing] technology becomes more user-friendly for medical professionals, more hospitals will be able to implement end-to-end solutions for personalized surgery,” says Gautam Gupta, vice president and general manager of 3D Systems medical devices practice. “This will disrupt existing healthcare models, improve the quality of care, and crucially, save more lives.”

The Kumovis acquisition fits nicely into 3D Systems’ established healthcare business and adds a new focus on decentralizing the production of medical implants.

“Shifting the manufacturing to the hospitals will be a game-changer when it comes to the availability of implants,” says Haerst.

For hospitals to become manufacturers, however, requires technical and engineering staff, regulatory processes, along with equipment. This could be managed on-site in a cooperative agreement by current medical device manufacturers, Haerst says.

PEEK Plastic vs. Titanium for Implants

PEEK has had FDA approval as an implant material for years when machined, but not yet when 3D printed. Although PEEK is used in numerous implants on the market today from spinal cages to ankle joints, 3D-printed PEEK still has to prove it has the same weight bearing and wear attributes as milled or molded PEEK.

Overall, this bio-compatible material has several perceived advantages over stainless steel and titanium: it’s lightweight, permeable to ultrasound, and practically invisible to CT and MRI scans enabling better post-op monitoring.

Over the years 3D-printed titanium gained a reputation for better bone integration and thousands of joint and spine implants are 3D printed every year by major manufacturers, such as Stryker. But PEEK has changed, says Marc Knebel, head of medical systems at Evonik, which manufactures PEEK for 3D printing as well as injection molding and milling.

“Today, PEEK can be designed with additives to gain new features, such as better osteointegration,” says Knebel. “We are working with a couple of hospitals on [3D-printed implants] already. The first ones will be active within the next five years.”

A 3D printing lab situated next to the operating room ready to churn out individualized implants designed from patient data at a moment’s notice is still a long way off. Regulatory hurdles remain, clinical studies are still in progress, and building buy-in from hospitals will take time. What we’re seeing today, however, are the innovators taking the first steps.