Accuracy of Navigated Osteotomies in Rhinoplasty: A Cadaveric Analysis

BACKGROUND: Navigation guided rhinoplasty allows detailed planning and guidance of osteotomies. We aimed to investigate whether the use of a CT navigation system is feasible and capable of performing more precise osteotomies at specific locations, thus improving accuracy. METHODS: Bilateral electromagnetic-navigated osteotomies (n = 18) of the nasomaxillary suture were performed on nine cadaver heads, using a transnasal (n = 4) or percutaneous (n = 14) technique. After dissection, we manually assessed the distance between the osteotomy and the suture on (n = 5) specimens. Additionally, at baseline and postoperatively, a cone beam computed tomography was performed to calculate the mean and median distance between the osteotomy and the suture line. RESULTS: The manually measured mean distance from intended to actual osteotomy was 0.75 mm (mm) (95% confidence interval [CI] 0.06-1.44 mm) with a median distance of 0.00 mm (interquartile range [IQR] 0.00-1.19 mm). In 6 of 10 procedures, the osteotomy was created according to plan with no visible deviation. Overall, on imaging, the navigation-guided osteotomies deviated from the suture by an average of 1.50 mm (95% CI 0.87-2.12 mm) with a standard deviation (SD) of 1.35 mm. The median distance was 0.73 mm (IQR 0.59-2.61 mm). The accuracies of transnasal and percutaneous osteotomies were similar (p = 0.63). CONCLUSION: Navigation-guided osteotomies demonstrated good feasibility with clinically useful sub-millimeter accuracy for both percutaneous and transnasal techniques. A model for postoperative outcome analysis is described with clinically useful accuracy, though not as high as direct observation. LEVEL OF EVIDENCE: N/A.