Finding the right size clothing can be a frustrating experience, especially if you aren’t proportioned exactly like the designer envisioned. Just ask anyone who has gone through the frustration and work of trying on multiple pairs of pants or shoes in a department store, only to leave empty-handed. Size can be aggravating when the scale is not what was advertised (bigger or smaller than expected) or when you find yourself in between sizes (or at the extremes).
Now imagine that instead of needing a new pair of pants, you needed a new body part. Poorly fitting pants are one thing…a poorly fitting body part is entirely something else.
Like clothing, most medical implants or prosthetics come in discrete sizes. The good news is the sizes and shapes are based on lots of data about normal patient anatomy, so there is likely to be a size that is a good match. However, in cases where there is not a perfect off-the-shelf fit, surgeons must take matters into their own hands, modifying and shaping commercial products to create a better fit for their patients.
For example, mandibular implants are metal replacement parts that can fill in for a piece of the lower jaw bone that is removed due to trauma, infection or malignancy. Mandibular implants only come in a handful of sizes. Therefore, surgeons must bend and shape the implant during the surgery to make it align properly with a patient’s jaw. Getting it right is important. After all, the mandible allows us to bite and chew food, acts as an anchor for multiple muscles of the face and helps define facial profiles and features.
At VA Puget Sound Health Care Center, maxillofacial surgeons James Closmann and Jeffrey Houlton are taking the search for a perfect fit for their patients to the next level by harnessing the power of 3D printing to deliver adapted mandibular implants. Closmann and Houlton teamed up with engineers Chris Richburg and Patrick Aubin along with Eric Rombokas, Puget Sound Radiologist, and myself to create near-exact replicas of their patients’ mandible on the hospital’s Stratasys 3D printer in three recent cases. In each case, Closmann and Houlton could try out multiple sizes of mandibular implants and adjust the fit to each patient’s model days before the operation. That way, when they walked into the operating room for the case, they already had a perfect fit for the patient in hand. The equivalent would be skipping all the acrobatics and frustration of the dressing room and grabbing the perfect pair of pants on the first try. Just as in the clothing scenario, the big savings here is time and energy.
“3D printed modeling, along with virtual planning, has really become a game changer in difficult mandibular reconstruction cases,” said Houlton. “Being able to have a 3D printed model of the patient’s mandible allows us to precisely plan key details during these cases, with a precision you just can’t get with traditional techniques.”
On top of the medical gains associated with the made-to-order mandibular implants, the custom 3D printed models translated into a time savings of approximately two hours per surgery. This means less time under anesthesia for the patient, less surgeon fatigue, and more opportunity to care for another patient in the operating room. And with OR time estimated at approximately $80 a minute, there is also a significant cost savings.
While 3D printed mandibles demonstrate one compelling use for pre-surgical device sizing and shaping, there are multiple additional ways 3D printing can directly benefit patients. For example, VA Puget Sound is also using 3D printing to help surgeons identify the most appropriate heart valve size for replacement surgery – something that can be the difference between life and death. There is also the potential for personalized orthopedic implants for patient needs that fall at the extremes of the size range. Just as a tailor can create the perfect jacket for a person, 3D printing can create the perfect fitting implant for a patient who will not be adequately served by one of the stock options.
“It is exciting to see this technology being offered to veterans through the VA system,” said Houlton. “The next step will be to use the 3D printer to create additional tools to help with optimal fit, such as surgical cutting guides. The dream is to eventually 3D print the perfect implant with a metal 3D printer every time.”
This is the newest story of the Stratasys and Veteran’s Affairs (VA) collaboration as part of the Stratasys Corporate Social Responsibility (CSR) Program; a success story about how to harness 3D printing for mandibular surgeries.