With 3D Printing, Stryker Orthopaedics Moves Toward Patient-Specific Implants
By Brett Brune
Editor, Smart Manufacturing
Stryker Orthopaedics is considering working with hospital groups internationally to create a small 3D printer that would turn out customized implants in hospitals, Gene Kulesha, senior director of platform technology engineering at the US firm, told people attending the Mfg4 conference yesterday in Hartford, CT.
Five to seven years from now, the partners envision that hospitals will house not only 3D printers but also dedicated design engineers, he said. Such “print engineers” would gather the diagnostic data from patients and surgeons, quickly design personalized implants, print them within six hours, sterilize them and deliver them to the surgeons.
“Right now, the first step is to have the implant ready in maybe a week’s time—for the second surgery,” Kulesha said.
Homer Stryker, an orthopedic surgeon and prolific inventor, founded the firm, which last year recorded sales of $9.9 billion, Kulesha said, noting that that figure hovered around $800 million when he joined the firm 20 years ago. “He would just crank out inventions left and right: bed frames, special heel inserts so people could walk on casts. He invented the cast cutter back in the 1940s.”
With nearly 5000 patents to its name, Stryker knows something about giving its engineers latitude.
One engineer with some machine time on his hands recently designed some chain mail on his CAD system. Out of the 3D printer, “we pulled out exactly what he had on the CAD machine: perfectly interconnected chain mail,” Kulesha said. “Now, we’re looking at it for potential clinical applications. Even if we don’t find anything there, it’s certainly a very cool thing to do: It shows the resolution and control we have on our 3D printers.”
Some new markets dictate the use of 3D printing.
“As the patient populations are getting younger in the US, the demands are growing and the requirements for materials and designs may start growing rapidly,” because the recipients of its implants are much more active than they were a few years back, Kulesha said. And, he added, 3D printing is looking like the best option his firm has to satisfy “the newer customer base of the 21st century.”
He said the firm sells hundreds of thousands of hip and knee implants each year. The Triathlon Tritanium cementless knee is a flagship product, and two if its components are 3D printed, he noted.
The final step in the standard of care for arthritis of the hip and knee is called total joint arthroplasty. Stryker builds components for both—to replace broken down articulating cartilage. “Those are implanted, and surgeons rebuild the joint to recreate proper articulation at various aspects of the joint and enable people to start walking again.”
Fixation surfaces got the company into 3D printing, Kulesha said.
“Thirty years ago, a lot of these joints would be cemented or glued into the bone,”” he added. “We’ve been working to develop biologic fixation surfaces that have a rough appearance and often a porous structure, as well. The Intention is to press fit the implant into the bone.”
In years past, design changes took “four to five weeks for retooling and redesign and such,” Kulesha said. “With 3D printing, it takes a matter of days. Every element of porous structure is created in the computer model. So we have 100% control of this porous structure we are designing for biological fixation.”
One design change, at least, stands out as noteworthy, he added. “Only 3D printing allows us to build composite, porous and solid regions within the implant, so we can have an area of solid and then surround that area of solid with a porous titanium feature for biologic fixation.”
Stryker is building a global center of excellence in Cork, Ireland.
That center will house some 3D printing R&D. “We plan to expand the technology to other products. We’ve got about 60,000 implants implanted, predominantly knees and spine,” Kulesha said. “We’re looking at spreading that out across the entire corporation--not only into implants but also into l instruments, and things of that nature.”
The firm will also investigate materials beyond titanium, on which its “bread and butter business” is based, he said. Possibilities include polymeric systems, nickel titanium and stainless steel.
Published Date : 5/5/2016