Intraoperative Autologous Bone Grafting with 3D CAD/CAM

Hypothesis: A subtractive 3D CAD/CAM device can produce accurate bone and cartilage autografts on demand in the operating room. This process can save money by reducing operating room time, and reducing the need for expensive inventories of various shapes, sizes, and types of prosthetic devices. Also, autologous materials are less likely to extrude or cause other complications such as infection. This also can reduce overall costs.

Background: Conventional middle ear prosthetics such as TORPs and PORPs are expensive, require large inventories for otologic surgery services, and carry the risk of extrusion. Autologous bone and cartilage can be used for many of these applications, but it requires expensive operating room time for carving to the appropriate shape and size. A subtractive 3D CAD/CAM device in the operating room can quickly produce accurate bone and cartilage autografts on demand, resulting in significant cost savings.

Methods: A Roland MDX series milling machine (Roland DGA, Irvine, California, United States) was selected. This machine has been used commercially to produce orthopedic allograft materials. Conventional CAD/CAM software was utilized. Commercially available bovine byproducts were utilized to provide bone materials for testing.

Results: Bovine cadaveric bone and cartilage utilization resulted in reliable production of prototype “TORPs,” “PORPs,” and cartilage auricular frameworks such as those utilized for microtia/anotia reconstruction providing proof of concept.

Conclusion: Subtractive 3D CAD/CAM devices in the operating room can produce accurate bone autografts on demand in the operating room. This process can save money by reducing operative procedure times, reducing the need for expensive prosthetic devices, and reducing hospital inventory expense. Autologous materials are also less likely to extrude or cause other complications such as infection. This study utilized bovine materials to develop the proof of concept. Institutional review board approved trials with actual human otologic surgeries are pending.