110. Production of Cartilaginous Auricular Frameworks With a Redesigned Device: Interlocking Subunits for Enhanced Stability and Reduced Wire Fixation

PURPOSE: During microtia repair, the quality of manually carved cartilaginous frameworks is highly operator-dependent, and the traditional carving process is imprecise, time-consuming, and often requires extensive wire fixation. Poor anatomical resemblance, construct sturdiness, and long-term stability can result. Limitations of this technique include the high number of wires needed (upwards of 85 wires), their cost and availability, as well as susceptibility to extrusion, which can result in infection and possible resorption of the construct. We present a modified design of our device to improve anatomical accuracy, while aiming to reduce construction time, enhance construct stability, and potentially decrease the number of wires required for fixation. METHODS: An updated design of our patented and previously published device was obtained using Computer-aided design (CAD) software, and blades were fabricated as resin models with a Stratasys J55 Prime Polyjet 3D printer. The accuracy of the test resin blades was evaluated by production of 3D-printed resin models of the planned subunit cut-outs using the new blades. Proof-of-concept evaluation of the tongue-in-groove interlocking mechanism, framework stability with fewer wires, and simplicity of assembly was assessed. RESULTS: The test blades were fabricated in resin for preliminary evaluation, with the final blades intended to be manufactured in metal. The predicted shapes of the cartilage subunits cut by the metal blades were produced using CAD files of the blades. The resin-printed subunits interlocked easily and precisely, showing significant sturdiness and rigidity. These improvements are expected to facilitate wiring, reduce wire numbers, and contribute to a more stable framework. Additionally, the enhanced anatomical resemblance of the subunits compared to the previous version suggests a projected improvement in the final ear shape. CONCLUSION: The modified blade design is intended to enhance the fabrication process of cartilaginous ear frameworks. By facilitating the production of interlocking subunits that offer superior anatomical accuracy and rigidity, we aim to optimize ear carving techniques and diminish reliance on wire fixation. These innovations are expected to refine ear morphology and improve the overall efficiency of auricular reconstruction. Future investigations will focus on validating these outcomes through in-human trials and customizing blade designs to create patient-specific auricular frameworks.