Usefulness of fronto-orbital advancement using integrated osteotomy of the frontal bone and supraorbital bar for craniosynostosis

<p>Background: Fronto-orbital advancement (FOA) with gradual distraction is often performed for craniosynostosis involving the coronal and metopic sutures. Inadequate advancement of the supraorbital bar and misalignment between the anterior forehead bone and the supraorbital bar is known to be associated with significant cosmetic concerns. Osteotomy, which integrates the frontal bone with the supraorbital bar, is useful to avoid misalignment. In this report, we describe the surgical procedure and its usefulness in clinical practice.</p><p>Materials and Methods: The study included 33 patients who underwent FOA with gradual distraction for the first time between March 2009 and September 2020. The following surgical methods were used: (a) frontal bone and supraorbital bar separation and fixation using an absorbable plate (segregated osteotomy [SO], 15 cases) and (b) osteotomy of the frontal bone and supraorbital bar in one piece (integrated osteotomy [IO], 18 cases). Four bone extenders were attached to the parietal and temporal areas on both sides. Distraction was performed at a rate of 0.5-1.5 mm/day beginning one week postoperatively. The distance from the supraorbital margin perpendicular to the line was measured, and the difference before and after extension was defined as misalignment.</p><p>Results: The male: female ratios in the SO and IO groups were 7:8 and 14:4, respectively. The mean ages in the SO and IO groups were 1 year and 5 months and 3 years and 5 months, respectively (p=0.004). The mean weights in the SO and IO groups were 8.9 kg and 13.4 kg, respectively (p=0.01). The operative times in the SO and IO groups were 231 min and 246 min, respectively. Estimated blood loss in the SO and IO groups was 125 mL and 127 mL, respectively; however, the blood transfusion rate of 67% in the SO group was significantly higher than 22% in the IO group (p=0.02). No significant intergroup difference was observed in the amount of bone extension (7.1 mm/8.9 mm in the temporal and 12.1 mm/12.3 mm in the parietal region). Mean misalignment between the frontal bone and the supraorbital bar at the end of extension was 1.87 mm in the SO group. No misalignment occurred in the IO group.</p><p>Conclusion: IO is not inferior to SO with regard to operative time, blood loss, or surgical complications and is not technically more complicated compared with SO. Osteotomy can be performed with a wider field through the window opening and provides sufficient space for repair in cases of dural injury, which serve as advantages of this approach. In our view, IO is an effective surgical approach to avoid the risk of misalignment of the frontal bone and supraorbital bar.</p>