How Stryker Is Growing Its 3-D Printing Options

The company is rolling out a spinal cage printed with a highly porous titanium alloy.

Nancy Crotti

Stryker has introduced a 3-D printed spinal cage designed to promote bone ingrowth and lumbar fixation for patients with degenerative disc disease.

The Tritanium PL Cage, cleared by FDA earlier this year, is constructed of a highly porous titanium alloy designed to mimic cancellous bone, a type of spongy bone tissue. It is indicated for use as an adjunct to fusion in patients with degenerative disc disease at one level or two contiguous levels from L2 to S1, and for patients diagnosed with degenerative scoliosis. Stryker's Spine Division introduced the device at the American Association of Neurological Surgeons Annual Meeting this week in Chicago.

"Spine surgeons need a cage that has the capability of bony integration or bony in-growth, as well as radiolucency so that we can evaluate the fusion long term," said Dr. Wellington Hsu, M.D., Orthopaedic Surgeon at Northwestern Medical Group, in a statement. "Because Tritanium has favorable radiographic capabilities, as well as the integrative surface technology, that really in my opinion is what I would ask for from an interbody cage."

The cage was designed to be implanted via a posterior approach to avoid damaging muscle tissue around the spine. Its serrations allow for bidirectional fixation and to maximize surface area for endplate contact with the cage. The device also has large lateral windows and open architecture to allow viewing the fusion on CT and X-ray, according to the company.  It will be available in mid-2016, in several sizes, widths, lengths, heights, and lordotic angles.

Stryker's Spine division conducted a pre-clinical animal study to investigate the biomechanical performance and bone in-growth potential of lumbar interbody fusion implants using different surface technologies. The study has been accepted as a podium presentation at the NASS Annual Meeting being held October 26-29, 2016, in Boston, the company said.

The market for 3-D-printed orthopedic implants may be small now, but could grow quickly going forward, according to a reportin the MIT Technology Review. Aging baby boomers will likely need more implants, and engineers have improved their skills in making titanium implants from titanium, the article said.

The number of total hip replacements in patients aged 45 and older more than doubled from 2000 to 2010, according to the Centers for Disease Control, with implants in younger patients on the rise. Investment firm ARK Invest  recently predicted that the market for 3-D-printed devices is expected to grow 40% annually.

Stryker is a building a $400 million 3-D printing plant this year. In 2015, it added 3-D-printed tibial baseplates and patellas to its Triathlon Tritanium Knee System and Triathlon Tritanium Cone Augments for knee surgeries, according to a report by 3Dprint.com. The company has a"huge line up of other divisions with ideas and prototypes" for 3-D printed titanium products, Stryker CEO Kevin Lobo told analysts during a fourth-quarter 2015 earnings call, according to a transcript provided by Seeking Alpha.

Lobo does not foresee metal 3-D printed devices replacing conventionally manufactured implants anytime soon.

"I would just say that it's more complicated than plastics or other things that you read about in the mainstream press, and that's why for us, our focus is much more on innovative new products and not necessarily replacing total systems that will be many, many, many years ahead of us," Lobo said.

Companies hope to cut costs by simplifying the production process for 3-D printed metal implants, which the MIT report described as "often geometrically complicated assemblies of multiple metal pieces."

"Building them layer by layer allows companies to consolidate many pieces into one, and save material that would be wasted in traditional subtractive manufacturing processes like forging and casting," the MIT report said.

Nancy Crotti is a contributor to Qmed and MPMN.

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