At MD Anderson, Revolutionizing Complex Surgery Via 3D Printing
In the end it was a good thing that Sophie’s* husband wasn’t paying attention. She was trying to prove that she could, in fact, jump and click her heels together twice before landing. But he missed her performance. So she did it again, but when she landed, her left leg was flooded with pain, keeping her awake that night.
Although the pain eventually subsided, the accompanying swelling did not, so she went to the doctor. An ultrasound led to an X-ray led to an MRI that led to the day in May 2018 when she learned that the lump in the back of her leg was parosteal osteosarcoma—cancer of the bone and surrounding connective tissue. She was 27.
The next month, with husband, parents, and dog in tow, Sophie moved from Colorado to Houston, where she would spend the next nine months under the care of Dr. Justin Bird, an orthopedic surgeon at MD Anderson Cancer Hospital. Before meeting Bird, Sophie had prepared for the end of life as she knew it. The tumor was above her knee. She feared losing her whole leg, and that she would never again hike, bike, or walk her puggle.
Bird had good news, all things considered. The aggressive nature of the sarcoma meant it had to come out all at once. Historically that meant removing all surrounding ligaments and replacing the knee joint with a metal implant, with Sophie going through surgeries for the rest of her life whenever the implant wore out. But when reviewing her case, Bird saw an opportunity to go a different direction. If his resection was precise, he could save the knee, removing just the tumor, cancerous bone, and surrounding tissue without taking an iota of extra material. The procedure was possible thanks to 3D printing.
An early adopter of the innovation, Bird knew his young, otherwise healthy patient was the perfect candidate for what he calls “technology-enabled precision surgery.” Using scans of Sophie’s femur, Bird worked with an engineer to develop a computer-generated, three-dimensional model of the entire structure, tumor and bone included, plus cutting guides he could pin to his patient’s leg during surgery to show exactly where and how to cut both Sophie’s femur and the donated cadaver bone that would replace it. The result: a perfect fit, like a puzzle piece, with minimal loss of healthy tissue.
3D printing can be useful in a wide variety of treatments, particularly complex cases that might require multi-day surgeries with many moving parts. The technology provides a template that allows doctors to anticipate potential challenges and devise a plan of attack before ever scrubbing in. “The worst place in the world to make a decision is in the operating room,” says Dr. Alex Mericli, a plastic surgeon at MD Anderson. Using 3D-printed cutting guides based on a patient’s scans eliminates trial and error when it comes time for Mericli to carve a piece of leg bone or pelvis or shoulder blade or jaw. “It basically fits like a hand in a glove,” he says.
Printed replicas also can aid communication, whether between multidisciplinary teams of doctors or between doctors and patients. The latter is so important to MD Anderson breast imagers Dr. Elsa Arribas and Dr. Lumarie Santiago that, for the past two years, after getting their own machine and lab space, they’ve 3D-printed their own breast models in house, something they say helps patients facing deeply personal, often overwhelming diagnoses. “It breaks down the communication barrier of medical lingo into something tangible,” Santiago says. “This is your breast. This is your particular entity.”
Arribas and Santiago not only print before models with tumors based on radiology reports, they also make after models to show what exactly chemo does. “You can see why you’ve lost your hair, why you’ve had all these terrible side effects: This is what my treatment was doing to my cancer,” Santiago says. “It makes it very concrete, the sacrifice that woman is making—because chemo is a sacrifice.”
Speaking of chemo, Sophie finished hers in February, eight months after surgery. She’s now back at work as a structural engineer in Colorado, where she’s undergoing physical therapy to improve her leg strength and bend her knee, which doctors predict will soon be able to bear weight normally, meaning she’ll once again be able to get out and exercise with her dog. Every three months she’ll get surveillance scans; she’ll return to Houston regularly to see Bird. “It’s very unlucky to have gotten cancer in the first place,” she says, “but I think in many other ways we have been very, very lucky.”
*Sophie's last name has been withheld to protect her privacy.