Mayo Clinic Creates Free 3D Printed Spine Surgery Simulator for Medical Training

The ongoing COVID-19 pandemic has demanded an unprecedented response from healthcare systems around the world. And to overcome the visible impact caused by the disease, the medical field is heavily relying on 3D printing technologies, digital trends, telehealth, artificial intelligence, and robotics. If crises can accelerate innovation and collaboration, then this pandemic has proven that innovators from a wide range of fields, working together to confront the outbreak, will play a critical role in enabling the breakthroughs needed for humanity to advance.

As part of their continuing efforts to share knowledge, a team of experts at the 3D printing lab at Mayo Clinic’s Department of Neurosurgery—the B.R.A.I.N. (Biotechnology Research and Innovation Neuroscience) Laboratory—have created the first open-access, 3D-printed simulator for resident and medical student education in spinal anatomy and pedicle screw placement.

Also known as SpineBox, the simulator design can be 3D printed on any desktop device, has a total cost of under 10 dollars, can be disseminated to neurosurgical and orthopedic residents training in spinal surgery to continue their practice during the current operative furlough, and the STL file can be downloaded for free at the Autodesk Online Gallery, or by following the link here.

The creators of SpineBox and co-founders of B.R.A.I.N., William Clifton, a neurosurgery resident at the Mayo Clinic in Florida, and Aaron Damon, a researcher and lab specialist at the Simulation Center at the Mayo Clinic, recently published a paper in Cureus describing the process behind their development, as well as its uses in anatomical education and training for pedicle screw placement in the lumbar region of the spine.

The study aims to provide institutions across the world with an economical and feasible means of spine surgery simulation for neurosurgical trainees and to encourage other rapid prototyping laboratories to investigate innovative means for creating educational surgical platforms. According to the authors of the article, the rarity of cases and relatively low general incidence of neurosurgical diseases—compared to other surgical subspecialties—presents challenges to ensure that trainees have adequate exposure to procedures that can help them become well-trained surgical physicians.

Moreover, as the world came to a halt amid the coronavirus pandemic, medical students were sidelined from their training as schools ended contact with patients. In the United States, 90,000 medical students have responded with grassroots efforts to secure masks, staff-patient call centers, and even provide childcare for healthcare workers who need to be at the frontlines. Even if students go back to school sometime this year, the current global situation has proven how important it is to have access to learning tools that are mobile and independent of hospital-related conditions.

The recent outbreak has diminished many neurosurgical learning opportunities throughout the world due to conference cancellations, decreased operating room utility, and quarantine policies. In the study, Clifton and Damon revealed that a simulator design that is easily created and portable for dissemination to neurosurgical trainees does not exist. That was something they were eager to develop and share with the medical community.

The five co-authors of the paper, including Clifton and Damon, along with Mayo Clinic neurosurgeons Mark Pichelmann, Eric Nottmeier, and Fidel Valero-Moreno, decided to carry out this project to provide institutions across the world with a cost-effective, easily available “in-house” model.

During the study, ten SpineBoxes were successfully printed using acrylonitrile butadiene styrene (ABS) filament on a Raise3D Pro Plus fused deposition modeling (FDM) 3D printer. It took the team 30 hours and $9.68 of material to print each SpineBox.

The team first acquired an anonymized CT scan of the lumbar spine of an adult patient to produce lumbar vertebral models that adequately replicated normal surface anatomy. The CT scan was then uploaded into the open source 3D Slicer platform, where five lumbar vertebrates (L1-L5) were individually selected, and facet joints and intervertebral spaces were manually separated to produce individually segmented models of the lumbar vertebrae. Each of the five lumbar vertebral models was then converted into an STL file and uploaded into the CAD software platform Meshmixer, which was also used to construct a virtual housing box for the vertebral models. The sliced SpineBox STL file was converted into a G-code to finally be 3D printed.

In order to enhance the educational experience, the team decided that they would also replicate the soft tissue structure by creating a soft barrier so that medical trainees wouldn’t see the vertebral model directly, providing a surgical environment that enabled them to operate in realistic conditions. In this case, they decided to cut flexible upholstery polyurethane foam sheets to fit the dimensions of the simulator housing box (at 17.6 x 18.6 cm). After the assembly was complete, the very realistic simulator allowed trainees to cut through the foam with a scalpel and use surgical retractors to simulate the separation of the soft tissue after the incision, allowing them to see into the operative cavity.

The use of polyurethane foam for soft tissue simulation as in a live operative scenario (Credit: Clifton, Damon, Valero-Moreno)

As described in the paper, Clifton and Damon have already begun using CAD design and 3D printing at the Mayo Clinic, in Jacksonville, to construct SpineBox simulators, which are also disposable and able to replicate the cortico-cancellous interface for pedicle screw placement.

The primary learning goal of the simulator was to instruct junior neurosurgical trainees in the anatomy and technique for pedicle screw placement in the lumbar spine. As stated in the study, they have already 3D-printed 10 SpineBox models for training, which were used to place a total of 100 pedicle screws in 50 lumbar levels.

The pedicle screws of the 3D-printed lumbar vertebrae can be seen within the model after being placed and graded based on location for both teaching and objective skill assessment (Credit: Clifton, Damon, Valero-Moreno)

3D printing has already proven to be a technology that can provide the means to recreate key points of anatomy for anatomical and procedural learning. This is especially true in the realm of spinal surgery, as with Clifton and Damon’s original Biomimetic Human Tissue Simulators, another training model they developed to help hundreds of medical residents improve their skills. Furthermore, as many institutions around the world continue to acquire  desktop 3D printers, they will need more open-access and cheap simulator designs that do not require purchase or extensive assembly.

The SpineBox simulator represents the result of many years of research focused on innovation in healthcare education. In addition, it can change the way medical schools prepare physicians for the demands of the future, especially as hospitals and procedures continue to undergo changes in the era of the pandemic.

Clearly committed to using 3D printing to revolutionize the way surgeons are taught, Clifton and Damon continue to surprise us with their improved designs and free-access delivery of simulators to any institution around the world that needs them, surely, many will take advantage of this new development.