Investigation using single point incremental forming (SPIF) to fabricate patient-specific, titanium orbital floor implants

¹ Department of Mechanical Engineering, Bucknell University, Lewisburg, PA, 17837, USA
² Plastic and Reconstructive Surgery, Geisinger Medical Center, Danville, PA, 17822, USA

^* Corresponding author: emm047@bucknell.edu

Abstract

The floor of the human orbit is composed of thin bone that is prone to traumatic fracture. This leads to a loss of support for the eye, which can cause vision changes. Therefore, fractures may need surgical reconstruction using a thin, sheet-like implant. Titanium implants are available off-the-shelf in standard sizes, but fitting to each patient's unique anatomy requires surgeons to cut, file, and bend these plates. This can be time-consuming and imprecise. To both save time and ensure a perfect fit for the patient, a custom plate can be created prior to surgery. This investigation focuses on single-point incremental forming as a novel technique to fabricate patient-specific orbital floor implants. This method for sheet metal forming of biocompatible titanium (commercially pure grade 2) is faster, more flexible, and creates less waste than conventional methods. Implant geometry can be manipulated by modifying the toolpath and process parameters. This allows customization to match the patient's precise anatomy, resetting the eye to an appropriate position. The microstructure of the formed part can also be controlled, increasing strength in fixation areas. Incremental forming has the potential to revolutionize the implant manufacturing industry through the generation of functionally-graded components.