Feasibility of clinician-facilitated 3D printing of synthetic cranioplasty flaps

Objectives 3D scanning and stereolithographic printing technology becoming increasingly common, however its implementation into clinical practice is in its primacy. These technologies may be esoteric to the practicing neurosurgeon. We explored a range of 3D scanning and stereolithographic techniques to create patient-specific synthetic implants. Methods We simulated bilateral craniectomies from a single cadaveric specimen to create 3 methods of creating stereolithographically-viable virtual models. Firstly, we used ‘pre-and-post operative’ CT derived bony windows to create a virtual skull model, from which the flap was extracted. Secondly, we used an entry-level 3D light-scanner to scan and render models of the individual bone pieces. Thirdly, we used an arm-mounted, 3D laser-scanner to create virtual models using a real-time approach. Results Flaps were printed from the CT scanner and laser scanner models only, in a UV-cured polymer. The light scanner did not produce suitable virtual models for printing. The CT scanner derived models required extensive post-fabrication modification to fit the existing defects. The laser-scanner models assumed good fit within the defects without any modification. Conclusions The methods presented varying levels of complexity in acquisition and model rendering. Each technique required hardware at varying in price points from $0 to ∼$100,000. The laser-scanner models produced the best quality parts which bore near-perfect fit with the original defects. We discuss potential neurosurgical applications of this technology.