COLUMBIA, Mo. - Using 3-dimensional printing technology at the University of Missouri College of Engineering, MU Health Care orthopaedic surgeons are able hold an exact replica of a patient's bone in their hands before ever walking into the operating room.
The bone models help MU surgeons to carefully plan complex spine and joint procedures before surgery, reducing time in the O.R.
"As a spine surgeon, I find this 3-D modeling capability is useful in procedures to correct extreme spinal deformities, such as abnormal curvatures of the spine," said Craig Kuhns, M.D., an orthopaedic surgeon at the Missouri Orthopaedic Institute. "For relatively mild deformities, I can plan my surgical approach by examining 2-dimensional CT scans of the patient's spine. But for a patient with very severe spinal problems, it can be difficult to visualize the exact anatomy of the spine from a 2-dimensional image, since it is so different from normal."
Kuhns has used models to help with procedures to correct severe cases of scoliosis, an abnormal side-to-side curvature of the spine, and kyphosis, an abnormal front-to-back curvature of the spine.
"A tangible 3-dimensional model helps me plan exactly where to place the screws and rods to straighten the spine, or determine which sections of malformed vertebrae I need to remove," he said. "By holding the model in my hands and examining it, I also know exactly what the bone will look like in the O.R."
Ferris Pfeiffer, Ph.D., a Mizzou Advantage Scholar and assistant professor of orthopaedic surgery and biological engineering at MU, works with surgeons at MU Health Care and the MU Veterinary Medical Teaching Hospital to create models used to plan surgeries for both humans and animals. Pfeiffer uses specialized computer software to transform a series of 2-dimensional images from a computed tomography (CT) scan of a patient's spine, leg or other bone into a 3-D computer model. After creating the computer model, Pfeiffer loads that file into one of the 3-D printers in the College of Engineering's Prototype Development Facility.
"With four different kinds of 3-D printers, our rapid-prototyping lab here at MU is one of the largest in the Midwest," Pfeiffer said. "One of the benefits of having this rapid prototyping lab right here is our ability to collaborate among different disciplines. I'm able to use my mechanical engineering expertise to create models for physicians and veterinarians. And since we're right here on campus, we're able to produce the models quickly, usually in 24 to 48 hours."
Children's Hospital pediatric orthopaedic surgeon Daniel Hoernschemeyer, M.D., has used the 3-D bone models to prepare for spine surgeries and procedures to correct hip dysplasia, a joint condition in which the upper-leg bone does not fit properly into its joint socket in the pelvis.
"I can even take the models into the O.R. to use as a roadmap during the procedure," Hoernschemeyer said. "In some of these cases of severe deformities, the anatomy looks very different from what it should look like. By bringing this model into the operating room, I can use it like a roadmap to show me exactly what part of the spine I'm looking at, where to cut and where to implant devices."