Page 130 - Advanced concepts in orbital wall fractures

Chapter 7
4. to design surgical templates, cutting guides, and patient- specific implants
5. for intraoperative navigation and imaging
6. for postoperative evaluation
7. as a learning tool for inexperienced surgeons, students, and
assistants
8. for research purposes
The complete package of software and hardware, including additive manufacturing (e.g. three-dimensional [3D] printing), a navigation system, and a computed tomography (CT) scanner for intraoperative use, is required to utilise all these features. This is expensive and involves numerous adjustments in daily clinical practice, such as a time-consuming preoperative planning phase, availability of onsite technological support, and adjustments of the preoperative scan protocol to include navigational markers. It is questionable whether this is feasible and necessary in every clinic and for all patients. It is important to critically assess if the costs and efforts outweigh the improved clinical outcomes and quality of life. By performing research on the individual components of CAS, it is possible to identify the important components. When individual components are successful, it might be worthwhile to apply these more widely in general clinics. Nevertheless, it is advisable to refer complex fractures to well- equipped tertiary clinics.
Virtual diagnostics and preoperative planning
Virtual diagnostics and preoperative planning software enable the surgeon to visualise the fracture in both 3D reconstruction and multiplanar views to carry out accurate measurements. An orbital wall fracture can result in an increase in volume of the orbital cavity. Enophthalmos might develop due to this volume increase. Measuring the volume provides insight into the severity of the fracture and is important in the diagnostic process. The semi-automatic method SA (automatic segmentation minus bone and air masks) proposed in chapter 2 contains the best combination of practical features to measure the volume of the intact bony orbit. The method is quick, accurate, and reproducible. The mean difference of 0.24 cc (SD 0.27) compared to the gold standard is small, especially in
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