Implant-oriented navigation in orbital reconstruction part II: preclinical cadaver study.

In orbital reconstruction, the acquired position of an orbital implant can be evaluated with the aid of intraoperative navigation. Feedback of the navigation system is only obtained after positioning of the implant: the implant's position is not tracked in real time during positioning. The surgeon has to interpret the navigation feedback and translate it to desired adjustments of the implant's position. In a previous study, a real-time implant-oriented navigation approach was introduced and the system's accuracy was evaluated. In this study, this real-time navigation approach was compared to a marker-based navigation approach in a preclinical set-up. Ten cadavers (20 orbital defects) were reconstructed twice, by two surgeons (total: 80 reconstructions). Implant positioning was significantly improved in the real-time implant-oriented approach in terms of roll (2.0° vs. 3.2°, P=0.03), yaw (2.2° vs. 3.4°, P=0.01) and translation (1.3mm vs. 1.8mm, P=0.005). Duration of the real-time navigation procedure was reduced (median 4.5 min vs. 7.5 min). Subjective appreciation of the navigation technique was higher for real-time implant-oriented navigation (mean 7.5 vs. 9.0). Real-time implant-oriented navigation feedback provides real-time, intuitive feedback to the surgeon, which leads to improved implant positioning and shortens duration of the navigation procedure.