Page 22 - Advanced concepts in orbital wall fractures

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Chapter 1
planning is necessary to quantify the volume increase and to plan the position of the implant. It produces an easy to understand three- dimensional (3D) virtual template. This mirroring technique is used on the assumption that both orbital cavities are symmetrical. In chapter 3, the best semi-automatic method for volume measurement is used to investigate whether the volume and contour of both orbital cavities are similar when mirrored. Considerable differences in volume or contour between both cavities may lead to fundamental errors in planning the orbital reconstruction. In this study, the aim is to measure the degree of asymmetry between both orbital cavities.
The studies presented in chapters 4 and 5 are part of a series of cadaveric research on computer-assisted technology and focus on intraoperative control during an orbital reconstruction. Both studies are performed using cadaveric heads with intentionally created, bilateral, complex orbital wall fractures. The primary outcome is the degree of improvement of the implant position. In chapter 4, 3D diagnostics and preoperative virtual planning are used to prepare the surgeon for the orbital reconstruction. The surgeon is able to examine both the CT scan and the preoperative virtual plan on a computer screen in the operating theatre to improve the position of the implant. The aim of this study is to evaluate the accuracy and predictability of 3D diagnostics and preoperative virtual planning in orbital reconstruction, without the use of intraoperative navigation. In chapter 5, the effects of intraoperative CT imaging in orbital reconstruction are discussed. The question is whether an improved surgical outcome outweighs the disadvantages such as radiation exposure, increased operation time, and costs. The aim of this study is to investigate whether intraoperative CT imaging leads to improvement of the implant position and the number of scans required to satisfy the surgeon.
Part II Clinical perspective
The general aim of the studies presented in the previous part is the improvement of the workflow in orbital reconstruction using technological developments. Part III concentrates on the basics of orbital wall fracture management; indications and timing of surgery. There is no widely accepted clinical protocol that is supported by solid scientific evidence.