How Partial Skull Defect Affects Vulnerability of the Skull in Traumatic Situations: A Biomechanical Study

Tomohisa Nagasao; Tomoki Miyanagi; Motoki Tamai; Asako Hatano; Yoshiaki Sakamoto; Naoki Takano

How Partial Skull Defect Affects Vulnerability of the Skull in Traumatic Situations: A Biomechanical Study

Eplasty. 2022 May 12:22:e13. eCollection 2022.

Authors

Tomohisa Nagasao¹, Tomoki Miyanagi¹, Motoki Tamai¹, Asako Hatano², Yoshiaki Sakamoto³, Naoki Takano⁴

Affiliations

¹ Department of Plastic and Reconstructive Surgery, Faculty of Medicine/Graduate School of Medicine, Kagawa University, Japan.
² Department of Plastic and Reconstructive Surgery, Sanno Hospital, Japan.
³ Department of Plastic and Reconstructive Surgery, Faculty of Medicine, Keio University, Tokyo, Japan.
⁴ Department of Mechanical Engineering, Keio University, Tokyo, Japan.

PMID: 35811644
PMCID: PMC9118030

Abstract

Background: Part of the skull can be lost due to neurosurgical diseases or trauma. Skulls with partial defects can develop different fracture patterns from those of intact skulls. This study aims to clarify the differences.

Methods: A 3-dimensional skull model was produced by referring to the computer-tomography data of a 23-year-old intact male volunteer. We defined the model as Intact Model. Another model was produced by removing part of the frontal bone, which was defined as Defect Model. Dynamic simulations of impacts were performed varying the site and direction of impact. Fracture patterns caused by the impacts were calculated using dynamic analysis software (LS-DYNA; Livermore Software Technology Corp.) and were compared between the intact model and defect model.

Results: When Defect Model was impacted, fracture involved wider areas than when Intact Model was impacted. This finding was observed not only when Defect Model was impacted on its defect side but also when it was impacted on its intact side.

Conclusions: When a skull carrying a defect on one side is impacted, serious fracture occurs even when the non-defect side is impacted, meaning that a skull with a defect is vulnerable to impacts on the non-defect side. This finding should be taken into consideration in deciding indications of skull defect reconstruction.

Keywords: defect; finite element; fracture; simulation; skull; trauma.

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