Generation of customized orbital implant templates using 3-dimensional printing for orbital wall reconstruction

Abstract

Objectives: To describe and evaluate a novel surgical approach to orbital wall reconstruction that uses three-dimensionally (3D) printed templates to mold a customized orbital implant.

Methods: A review was conducted of 11 consecutive patients who underwent orbital wall reconstruction using 3D-printed customized orbital implant templates. In these procedures, the orbital implant was 3D pressed during surgery and inserted into the fracture site. The outcomes of this approach were analyzed quantitatively by measuring the orbital tissue volumes within the bony orbit using computed tomography.

Results: All 11 orbital wall reconstructions (6 orbital floor and 5 medial wall fractures) were successful with no post operative ophthalmic complications. Statistically significant differences were found between the preoperative and post operative orbital tissue volumes for the affected orbit (24.00 ± 1.74 vs 22.31 ± 1.90 cm³; P = 0.003). There was no statistically significant difference found between the tissue volume of the contralateral unaffected orbit and the affected orbit after reconstruction (22.01 ± 1.60 cm³ vs 22.31 ± 1.90 cm³; P = 0.182).

Conclusion: 3D-printed customized orbital implant templates can be used to press and trim conventional implantable materials with patient-specific contours and sizes for optimal orbital wall reconstruction. It is difficult to design an orbital implant that exactly matches the shape and surface of a blowout fracture site due to the unique 3D structure of the orbit. The traditional surgical method is to visually inspect the fracture site and use eye measurements to cut a two-dimensional orbital implant that corresponds to the anatomical structure of the fracture site. However, implants that do not fit the anatomical structure of a fracture site well can cause complications such as enophthalmos, diplopia and displacement of the implant.

Fig. 1

Technique for preparation of a customized orbital implant template. a Preoperative virtual 3D orbital implant model for the fracture site. b Templates and press. The design of the upper and lower body of the templates was based on the virtual 3D orbital implant shown in a and c. Tracing of a template onto porous polyethylene with an embedded titanium implant and cutting out of the unnecessary parts. d After placement of the porous polyethylene with embedded titanium implant between the upper and lower body of the templates, it was inserted into the press to maintain the axis while pressing

Fig. 2

Three-dimensional volumetric measurements of the orbital tissue within the bony orbit. a Preoperative assessment. The arrow indicates the herniated orbital tissue through the bony defect of the left orbital floor fracture. b Post operative assessment. The herniated orbital tissue was reduced

Fig. 3

Preoperative (a, b, c) and post operative (d, e, f) CT scans and photo of patient 2. The left orbital floor fracture in sagittal view (a), three-dimensional reconstruction (b), and enophthalmos in left eye (c) are shown. Post operative images (d, e) revealed a good size and contour of the implant pressed and trimmed using a customized orbital implant template generated by 3-dimensional printing. The enophthalmos in left eye was improved (f). Preoperative (g, h, i) and post operative (j, k, l) CT scans of patient 5. The right medial wall fracture in coronal view (g), axial view (h), and three-dimensional reconstruction (i) are shown. Post operative images (j, k, l) demonstrated optimal positioning and configuration of the customized implant