We present a novel 3-dimensional (3D) printing method for low-cost and widely available reproduction of computed tomography (CT
)-based synthetic bone models for spine surgery simulation
, optimized to reproduce realistic haptic
properties. The method allows reproduction of either normal or abnormal patient anatomy. The models are fluoroscopy compatible and contain deformities and fractures present in the underlying CT
Spine models created from CT
data were printed on a 3D printer using 2 different materials for cortical and cancellous bone. Printing parameters were iteratively optimized with surgical experts and 3 candidate spine models were evaluated in a study regarding haptic
properties. X-ray images of a spine section printed with final printing parameters were evaluated by surgical experts regarding fluoroscopic properties.
Eleven surgical experts performed a trocar insertion, a typical workflow step in spine surgery procedures, on the models. We observed agreement that cortical structures and strong agreement that cancellous structures of the final model are haptically comparable with human vertebral bone. Ten surgical experts evaluated x-ray images of the model. They expressed strong agreement on the similarity with x-ray images of the human spine and confirmed the presence of a fracture. Material cost of a typical spine model is around US $11.
Models created using the novel methodology realistically reproduce the haptic
properties during a trocar placement into the vertebral body. The models are compatible with conventional x-ray imaging. Because the models correspond to real patient CT
data, those can alternatively be used in simulation environments that simulate fluoroscopy or CT
image guidance to produce highly realistic, radiation-free imaging output.