A Custom Silicone Foot Orthosis for Partial Calcanectomy Fabricated Using a 3D-Printed Mold

Abstract

ABSTRACT Introduction Patients with partial foot amputations are prone to skin breakdown due to concentrated contact stress and shearing. A custom silicone foot orthosis (FO) can be used to redistribute the concentrated stress and reduce the shearing and discomfort of the skin of a patient with partial calcanectomy. This study presents a custom silicone FO, which is molded using a 3D-printed mold. Methods The subject's left (amputated) partial foot and right (intact) foot were scanned using a 3D scanner. A custom silicone FO was designed by modifying the models of both feet. A mold for the FO was designed using computer-aided design software and fabricated by 3D printing. Room temperature vulcanization silicone was molded to fabricate the FO. The fit of the FO was clinically evaluated by the subject walking with the FO. Results A custom silicone FO was fabricated using a 3D-printed mold. Conclusions The custom silicone FO follows the contour of the residual foot to distribute pressure away from bony prominences during standing and ambulation. 3D printing of the mold can reduce labor time and material cost while facilitating the digital record when compared with a conventional plaster casting approach. Clinical Relevance The 3D printing approach used to fabricate the custom silicone FO may be applied to develop custom silicone orthotic/prosthetic devices for other types of partial foot amputations.