Post-traumatic zygomatic osteotomy and orbital floor reconstruction

Abstract

Purpose: Post-traumatic zygomatic osteotomy, fracture reduction, and orbital floor reconstruction poses many challenges for achieving a predictable, accurate, safe, and aesthetically pleasing result. This paper describes the successful application of Computer Aided Design (CAD) and Additive Manufacturing (AM) to every stage of the process – from planning to surgery. Approach: A multi-disciplinary team was employed - comprising surgeons, prosthetists, technicians and designers. The patient’s Computed Tomography (CT) scan data was segmented for bone and exported to a CAD software package. Medical models were fabricated using AM for diagnosis, patient communication, and device verification. The surgical approach was modelled in the virtual environment and a custom surgical cutting guide, custom bone-repositioning guide, custom zygomatic implant, and a custom orbital floor implant each designed, prototyped, iterated and validated using polymer AM prior to final fabrication using metal AM. Findings: Post-operative clinical outcomes were as planned. The patient’s facial symmetry was improved and their inability to fully close their eyelid was corrected. The length of the operation was reduced relative to the surgical team’s previous experiences. Post-operative scan analysis indicated a maximum deviation from the planned location for the largest piece of mobilised bone of 3.65mm. As a result, the orbital floor implant which was fixed to this bone demonstrated a maximum deviation of 4.44mm from the plan. Originality / value: This represents the first application of CAD and AM to every stage of the process for this procedure - from diagnosis, to planning, and to surgery.