麻豆传媒

News — The growing field of 3D printing is enabling solutions for some of the most challenging problems in orthopedics. At Hospital for Special Surgery (HSS), a sophisticated 3D printer is manufacturing custom-made joint replacements for highly complex cases when a standard “off the shelf” implant won’t work. HSS was the first hospital in the U.S. to house a 3D printing facility onsite for custom implants, in collaboration with LimaCorporate, which was recently acquired by Enovis.  

For most people needing joint replacement surgery, traditional implants, which come in a variety of sizes, will fit. However, widely available implants don’t work for everyone, and that’s where the extraordinary capabilities of 3D printing come in. For problems requiring complicated reconstructive surgery, the ability to customize a joint replacement has been a game-changer, according to , associate surgeon-in-chief at HSS. 

“Compared to traditional implant manufacturing, the magic of 3D printing is the ability to produce so many more complex shapes and designs in a fraction of the time,” explains Douglas Leach, vice president of Device Innovation at the HSS Innovation Institute.

At the Complex Joint Reconstruction Center at HSS, orthopedic surgeons see patients with severe deformities, massive bone loss, or failed joint replacements that need to be redone. For these patients, a custom-made 3D-printed implant could restore function and mobility or even save their limb. Implants made for specific patients have relieved relentless pain. They have enabled wheelchair-bound patients to walk again, Dr. Bostrom says.

Made of titanium, the implant is manufactured from very fine metal powder, which is poured onto a platform and leveled carefully. A laser or electron beam heats the powder layer and melts the material, which fuses to the layer below. Material is added layer by layer to create the implant.

From model to actual implant

Dr. Bostrom and his colleagues initially began using 3D printing at HSS more than a decade ago to quickly manufacture a plastic model – an exact replica of a patient’s knee, hip, shoulder or elbow – prior to performing a highly complex joint replacement.

“We get a CT scan and from that we can create an actual model of the patient's joint to help with planning the surgery before we go into the operating room,” explains , chief emeritus of the Surgical Arthritis Service at HSS. “Having the model before surgery has revolutionized the planning process of these difficult cases, helping us make sure we’re doing the right thing and getting the right fit.”

Fast forward 10 years, and the technology has advanced to where 3D printers are now producing the titanium implant that goes into the patient. Often used for complex or re-do hip replacement surgeries, the specially designed implants may also be the last and best hope for patients needing a complicated knee, shoulder or elbow replacement.

By the time patients come to the Complex Joint Reconstruction Center at HSS, they know they have a complicated problem, according to Dr. Bostrom. “Sometimes HSS is thought of as being the ‘the end of the line’ for these patients,” he says. They are grateful when they learn that a solution is in sight. 

Because all new medical devices require approval by the Food and Drug Administration, gaining permission to use a patient-specific 3D-printed implant can be a slow process. A waiver known as “compassionate use” must be obtained. Although it may take months, patients say it is worth the wait.