First 3D printed skull implant used in US made in South Windsor
By Christian Mysliwiec - Staff Writer
South Windsor - posted Fri., Mar. 15, 2013
A revolutionary medical milestone has been reached in the United States, and its origins are in Connecticut. For the first time, a polymer skull implant created from a 3D printer was used in surgery in the U.S., and that implant was designed and manufactured at Oxford Performance Materials (OPM) of South Windsor.
On Monday, Feb. 18, OPM announced that the OsteoFab Patient Specific Cranial Device, a 3D printed skull implant, received 510(k) approval from the U.S. Food and Drug Administration. The approval clears OPM to market this new medical device in the country. On Thursday, March 4, an OsteoFab implant was used in a skull surgery on a patient in Long Island.
While a first in the U.S., the OsteoFab implant has been in use for a year now outside of the country, specifically in South America and Australia.
OPM was founded by entrepreneur Scott DeFelice in 2000 as a materials company. The company's mission is to exploit polyetherketoneketone, or PEKK. OPM calls PEKK a “high performance thermoplastic technology” that is sturdy, lightweight, and resistant to heat and chemicals. The industrial division of OPM is developing parts for aerospace structures, parts for near-earth orbit space craft, and for defense applications. OPM has stated that its brands of biomedical polymers – the OXPEKK Medical Grade and OXPEKK Implant Grade – are similar to bone in density and stiffness, and can be sterilized using common sterilization methods. Used in spinal implants and dental parts, the polymers are replacing many medical devises traditionally made from stainless steel or titanium. It is the OXPEKK Implant Grade that is used to create the OsteoFab implants.
The need for a skull implant begins with a void in the human skull. This can be the result of trauma, such as a car crash, or a disease that necessitates the surgical removal of bone. When swelling recedes and the patient is stabilized, a CAT scan or MRI is performed. From this, a “slice file” is created which maps the defect in the skull. The slice file is sent to OPM staff members, who design a patient-specific implant to fill the void.
The goal is to replicate what naturally should be filling that gap. But with the technology at their disposal, OPM staff can add modifications. “The surgeon will have some ideas on other features,” said DeFelice. “They want scaffold structure, or places for screws.” They can also print features that are desirable for attachment and tissue growth to encourage safe recovery.
OPM's design is sent to the doctor, who signs off on it. The file returns to OPM, where it is organized into a “build.” Implants are created by the additive manufacturing process, also known as 3D printing. In the process, polymer powder (in this case, OXPEKK Implant Grade) is layered on a platform within the printing equipment. A process called “laser sintering” melts the powder into specific shapes. The platform lowers, another layer of powder is applied and sintered, and the process is repeated until complete. “Before you know it, you have all the parts floating in the powder, and you go excavate them all,” said DeFelice.
The laser sintering is not the only innovative technology that OPM uses involving light. “We print with light – lasers – and we also measure with light,” he said. They have a light metrology tool, which was also developed in Connecticut at the Connecticut Center for Advanced Technology, Inc., that allows OPM to perform selective light scans. “Basically, we shine a light on an object, and a light pattern tells us what shape the object is,” DeFelice said. A selective light scan is done on the printed OsteoFab implant, and the image is compared to the original source file to ensure that it was printed correctly. The reason for this step of due diligence is self-evident: “It's cool that we can build a complex, organic shape, but that has to go into someone's head,” said DeFelice. “The guy is on the table and you can't say, 'Oh, it doesn't fit.'” The selective light scan ensures that OPM gets the shape right the first time. If all looks well, the implant is shipped to the hospital.
How costly is OsteoFab? “Actually, it's a big money saver,” said DeFelice. The savings are not in the cost of the implant itself – an OsteoFab implant is comparable in price to traditional implants made of titanium mesh or machine-shaped plastic. Rather, the benefit is in the installation.
Unlike 3D printed implants, which are sculpted to precisely fit the skull gap, traditional implants are not an exact fit. DeFelice explained that as a result, the fit has to be made during surgery by trimming the implant or cutting bone – all while the skull is still open. In terms of cost, he said it is about $65 a minute to have a skull open during the surgical procedure, which accounts for anesthesia and the anesthesiologist on standby. In terms of safety, the longer the skull is open, the greater the risk for complication and infection. “Even though the [OsteoFab] implant may cost what the other implants cost, the economic benefit is very, very great,” said DeFelice. “It's really about the cost to install and own it, and you're less likely to get an infection.”
Skull implants are just one of the possible uses of the OsteoFab process. “We're moving right down the body,” said DeFelice. Diabetic feet, oncology cases, and salvaging tumor-afflicted limbs, he said, are topics of interest that OPM is poised to tackle.
“There's a lot of work to do, and we'll keep busy,” said DeFelice.