Theoretical model of pediatric orbital trapdoor fractures and provisional personalized 3D printing-assisted surgical solution

Abstract

Pediatric orbital trapdoor fractures are common in children and adolescents and usually require emergency surgical intervention. Herein, a personalized 3D printing-assisted approach to surgical treatment is proposed, serving to accurately and effectively repair pediatric orbital trapdoor fractures. We first investigated stress distribution in external force-induced orbital blowout fractures via numerical simulation, determining that maximum stresses on inferior and medial walls exceed those on superior and lateral walls and thus confer higher probability of fracture. We also examined 36 pediatric patients treated for orbital trapdoor fractures between 2014 and 2019 to verify our theoretical construct. Using 3D printing technique, we then created orbital models based on computed tomography (CT) studies of these patients. Absorbable implants were tailor-made, replicating those of 3D-printed models during surgical repairs of fractured orbital bones. As follow-up, we compared CT images and clinical parameters (extraocular movements, diplopia, enophthalmos) before and 12 months after operative procedures. There were only two patients with diplopia and six with enophthalmos >2 mm at 12 months, attesting to the efficacy of our novel 3D printing-assisted strategy.

Combined Subciliary/Transantral Approach for Reconstruction of Orbital Floor Fracture

“…No esthetic complication was found, suggesting possible superiority of a combined approach to single transorbital reconstruction in which incidence of postoperative diplopia was 9.1-42.5% [6,17]. Recently, Chai et al recommended an absorbable implant using a personalized 3D printing technique for pediatric TF [18]. A combined approach can yield results comparable to theirs (postoperative diplopia in 5.6%).…”

3D Printing in Eye Care

“…Both CT and MRI have been shown to create anatomical models accurately [ 67 , 68 ]. Templates can be sterilized for intraoperative use without losing their shape [ 69 , 70 ].…”

“…Optimal implant sizing through 3D printing helps prevent globe misalignment, strabismus, blood loss, and other postoperative complications [ 70 – 73 ]. Preoperative sizing reduces surgical time and limits fatigue of the implant material due to fewer adjustments [ 74 ].…”

“…The orbital literature concerning 3D-printed bony defect templates includes numerous reports of successful use in the orbital floor, medial wall, and lateral wall [ 67 , 78 – 81 ]. Chai et al published a study of 127 fracture repairs done with the aid of 3D-printed skull models [ 70 ]. Oh et al reported successful outcomes without complication in 104 patients [ 82 ].…”

“…In a retrospective study of 82 patients, Kim et al found that the 3D printing group had a smaller bony defect, shorter gap between implant and bony edge, and smaller angle between implant and natural bony contour [ 91 ]. Incorporating 3D printing into orbital fracture repair has been found to reduce surgical time by as much as 50% [ 70 , 92 ].…”