Page 144 - Advanced concepts in orbital wall fractures
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Chapter 8
the workflow. Computer-assisted surgery (CAS) consists of several preoperative, intraoperative, and postoperative components. Virtual three-dimensional (3D) diagnostics and preoperative planning include volume measurement, mirroring of the unaffected side onto the affected side, and virtual surgery to select the ideal implant. Intraoperative control is achieved with navigation and computed tomography (CT) imaging. The position of the implant can also be evaluated after surgery during postoperative analysis.
The most important consequences of orbital wall fractures are persistent diplopia and enophthalmos. There is no uniform treatment strategy for large fractures with initially severe diplopia and without early enophthalmos. The main discussion revolves around indications and timing of surgery. Proponents of a predominantly nonsurgical approach point to the regenerative capacity of the body to resolve diplopia and the rare development of late enophthalmos. Proponents of early surgical intervention propagate that it has better outcome and causes less iatrogenic damage.
The specific aims of this PhD thesis are:
1. To investigate the added value of relevant individual diagnostic,
preoperative, and intraoperative components of computer-
assisted orbital reconstruction.
2. To improve the management of orbital wall fractures by
assessing the implementation of an updated clinical protocol with special emphasis on functional outcome.
One of the first components in the workup of CAS is measurement of the increased orbital volume after an orbital fracture, as it can be useful in assessing the severity of the fracture. Chapter 2 describes three (semi-) automatic software segmentation methods to measure orbital volume in the unaffected bony orbit. Based on 21 CT scans, one unaffected orbit per scan is used to compare the gold standard, manual segmentation, with the three methods: method A (automatic), method SA (automatic minus bone and air masks), and method SAA (automatic minus both masks followed by manual adjustments). It can be concluded that method A is
























































































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