For most people, toys and trinkets come to mind when thinking about 3D printing. For the medical world, however, the technology ushers in the possibility of new therapies and treatments. Cancer patients requiring reconstructive surgery are likely to benefit from some recent landmark operations that have used this technology.
Printing a Pelvis
Dr. Craig Gerrand, a British orthopedic surgeon at Newcastle upon Tyne Hospitals, replaced a cancerous pelvis with one that was constructed by 3D printing. The patient was a 60-year-old man suffering from chondrosarcoma, a relatively rare form of bone cancer. The entire right side of the patient's pelvis needed to be removed. If the pelvis could not replaced, Dr. Gerrand would be unable to reattach the patient's leg. The leg would be unusable.
With 3D printing technology, a custom replacement pelvis was generated. Using information from both MRI and CT scans, the surgical team calculated the exact dimensions needed for the pelvis implant. Armed with these measurements, Stanmore Implants was able to print the titanium pelvis. Stanmore used an additive printing process, building the pelvis one layer at a time. For each layer, lasers fused titanium powder into solid metal. The completed pelvis was coated with a material conducive to bone growth, allowing the patient's remaining bone to fuse with the implant. A standard hip replacement could then be fit into the new pelvic socket.
There was a risk that the implant might fracture or fail to fit, but the patient chose to move forward with the surgery. The operation took 12 hours and required the use of computer-assisted navigation to ensure that the surgeons removed the precise amount of bone that matched the new implant. When it came time to insert the titanium pelvis, it was a perfect fit.
The pelvic surgery was done three years ago, and it was a success. The patient now walks using only the aid of a cane.
Making a Mandible
Head and neck cancer surgery sometimes leaves patients with significant facial disfigurements that can be difficult to live with. There may be new hope for these patients after recent ground-breaking surgery in which the entire lower jaw of an 83-year-old woman was replaced by a complete 3D printed mandible.
The woman had a long-term infection in her jaw bone, and it was progressing. She was too old to tolerate a prolonged microsurgical reconstruction procedure. Simply removing the diseased portions would have left too little bone; the woman would have been unable to use her jaw. Instead, the surgical team decided to reconstruct the entire jaw.
The process required a multidisciplinary approach with several institutions collaborating. The jaw itself was built by LayerWise NV, a Belgian manufacturer, using the fused titanium layering technique. Due to the multiple articulated joints involved, detailed modeling and precise measurements were required from the surgeons. A Cambioceramics artificial bone compound was used to coat the mandible prior to implanting. Dr. Jules Poukens, a maxillofacial surgeon from the University of Hasselt, led the team during the jaw replacement operation.
The surgery was highly successful. Within a few days, the patient was able to speak and swallow normally.
To the general population, a 3D printer may be a fun diversion. For cancer patients facing extensive bone surgery, this technology represents the possibility of a future that is both functional and free of disfigurement.
Website links: These are general links to the institutions involved.