Frontal Bone Fracture Patterns Suggesting Involvement of Optic Canal Damage

Purpose: Fracture of the frontal bone can be accompanied by damage to the optic canal. The present study uses finite element analysis to identify fracture patterns, suggesting the involvement of the optic canal. Methods: Ten finite-element skull models were generated from computer tomography data of 10 persons. Then, dynamic analyses simulating collision of a 2-cm-radius brass ball to 6 regions on the frontal bone in the 10 models were performed. Fracture patterns presented by the frontal bone in the 60 experiments were observed, and all those involving the optic canal were selected. Commonalities of the selected fracture patterns were identified. Results: Fracture of the optic canal was observed in 9 of the 60 patients. In all 9 patients, fracture existed on the anterior and posterior walls of the frontal sinus and on the superior orbital wall. Conclusion: When the anterior and posterior walls of the frontal sinus and the superior orbital wall are all broken, the optic canal is highly likely to be involved in the damage. When this pattern is observed in emergency examination, preventive decompression of the optic nerve should be considered to avoid potential occurrence of blindness. Address correspondence and reprint requests to Tomohisa Nagasao, MD, PhD, Department of Plastic and Reconstructive Surgery, Faculty of Medicine, Graduate School of Medicine, Kagawa University, Kagawa Prefecture, Kida County, Miki-Cho Ikenobe 1750-1, Japan; E-mail: nagasao@med.kagawa-u.ac.jp Received 11 March, 2018 Accepted 12 July, 2018 This study was approved by the institutional review board of Kagawa University. Part of the present study was supported by a Grant-in-Aid for Scientific Research (C: 15K01292) provided by the Ministry of Education, Culture, Sports, Science and Technology of the Japanese Government. The authors report no conflicts of interest. Supplemental digital contents are available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (https://ift.tt/2iuFjMi). © 2018 by Mutaz B. Habal, MD.

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