For Joanne Karas, every step meant pain. Born with a congenital hip defect, she underwent surgery at 12 months old and she felt fine until she reached her 40s. After an initial hip replacement, the pain returned and one leg had become noticeably shorter than the other. Then Joanne found Dr. Henry Finn, Chairman of Surgery at Weiss and Director of the Bone and Joint Center at Weiss, who is an expert in complex joint revision surgeries. Dr. Finn used 3-D printing technology to produce a replica of her hip.
“Her socket had moved into a vertical position, instead of a 45 degree angle,” says Dr. Finn. “It was loose and she had developed bone defects.”
X-Ray vs. CT Model – What’s the difference?
An X-Ray is a two-dimensional image and does not provide a physical model to hold that allows more thorough pre-surgery planning for the surgical team. For complex cases, a CT model – a model created using 3D printing – may be useful tool in pre-surgery planning. At Weiss, Dr. Finn sometimes uses CT models for patients with boney structures that are not normal, deficient, many of whom have congenital conditions. Many of the cases where the technology is used are unique and complex cases, in which the patient has had previous surgeries and the bone stock isn’t supported in the socket.
“With 3D printing of a model, we can see where there’s hardware, we can see what the bone deficiencies are,” Dr. Finn says. “But more importantly, you can actually hold the pelvis in your hands and plan for the surgery. It makes the surgery go quicker, it’s more reliable, and in some cases it enhances the recovery for the patient.”
Dr. Finn has been using orthopedic CT models for 15 years. With the help of the model in surgeries like Joanne’s, he can plan revision procedures step by step. Using the CT model, Dr. Finn rebuilt Joanne’s hip socket and inside the model pelvis, Dr. Finn could “rehearse” the surgery, placing a cup-cage construct, a metal device that connects the lower and upper parts of the pelvis.
Back on her feet again, with no limp and no pain, Joanne says “It’s like a miracle.”