Ultrasound guided injections are a common method of treating osteoarthritis in the equine cervical vertebrae. Typically veterinary students, grad students, interns, faculty and graduate vets train for this procedure using cadavers which is a race against time itself. Add to that a delay in gaining feedback on the results and the advantages of a 3D printed model become very clear.
Since 2018, zur Linden and his team have been working with Dr. Phillips, testing thirteen different types of materials and printers in combination to compare which model would work best to simulate real bone using ultrasound. Six of the materials proved suitable for simulating bone or joints for use with ultrasound. The team has succeeded in creating model vertebrae of the equine neck and embedded them in ballistics gel to simulate the soft tissues surrounding the bones. These models will give the veterinary community the opportunity to practice ultrasound guided procedures with instant feedback. The efficiency is beyond compare and the models are completely reusable! Once the lab practice is complete, the model can be melted down to remove all needle tracks and it is ready to go for the next use. Time will tell how many procedures can be practiced with one model.
“To create one of these models, the design engineer has the most time consuming job,” explains zur Linden. “Once we have a CT scan, a few weeks will be spent using software to segment out the anatomy that is to be printed. The printing of the model only takes 3 – 6 hours.” Post processing may involve removing supports, removing excess resin and curing to reveal a model that closely mimics bone. Then the 3D printed models can be embedded in clear ballistics gel to mimic skin and muscle, and degassed to remove all gas bubbles.
There is great potential for this technology to enhance student learning and to improve the quality of care for the patients. CT scans from unique cases could be used to create models that would provide vet students opportunities to practice with an array of abnormalities.
“This project, funded by Equine Guelph, afforded the opportunity to work with so many different printers and materials,” zur Linden says, “I am looking forward to sharing results and collaborating with other researchers, working on more challenging and different models including constructing blood vessels and airways for interventional radiology procedures.”