Implementation of 3D printing technology for complex spine revision cases that require multilevel anterior spinal support: Over 5-year experience in six cases and costs assessment.

Introduction: The anterior column of the spine is crucial for stability. In a dystrophic spine, the loss of multisegmental anterior spinal support can have devastating consequences. Since posterior instrumentation alone cannot take over the weight bearing capacity of the anterior column, structural anterior support must be created. Long bone struts are at risk for failure of engraftment and pseudoarthrosis. Patient-specific anterior support using 3D printing technology may be a better solution in these patients. Research question: Are patient-specific approaches using 3D printing technology a viable treatment option for multilevel anterior spinal support? Material and methods: Five patients received a custom-made anterior paravertebral titanium spinal strut prosthesis; one patient received a 3D shaped structural allograft. Cost assessment was made based on hours spent and production costs. Clinical outcomes were extracted from the medical records. Results: All six implantations went uneventful with adequate fit of the prostheses and allograft. The mean surgery time was 219 min, and mean blood loss was 850 ml. No implant subsidence or loosening occurred during follow-up (0.5-8 years). Complications observed were partial bronchial compression in one patient and a postoperative infection in another. The first cases were most costly due to the hours spent on design and regulatory compliance. These costs declined for subsequent cases. Discussion and conclusion: Custom-made prostheses appear to be a viable treatment option for multi-level anterior spinal support. No implant failure was observed up to 8 years postoperative. Close collaboration between an in-house 3D lab and the surgical team was essential for implementing custom-made prosthesis in clinical care.