Comparison of the Relapse Ratio and Osteogenesis Between 1-Piece and 2-Piece Fronto-Orbital Distraction Osteogenesis Among Patients With Bilateral Craniosynostosis in Early Childhood

Abstract

Background: Fronto-orbital distraction osteogenesis (FODO), used to correct bilateral coronal craniosynostosis (BCS), is grossly classified into 1-piece and 2-piece FODO. One-piece FODO osteomizes the frontal and supraorbital bones as one block by preserving the attachment between the dura mater and bone, whereas the 2-piece FODO detaches bone segments from the underlying dura mater and reshapes them. This study aimed to determine whether separating the bone-dura attachment would affect osteogenesis and the relapse of the deformity and to compare the surgical outcomes between 1-piece and 2-piece FODO.

Methods: Patients with BCS who underwent either 1-piece or 2-piece FODO between May 2008 and November 2016 were retrospectively reviewed. Patients older than 12 months who were diagnosed with syndromic or nonsyndromic craniosynostosis were included. The CT images were taken at initial presentation (T0), 1-3 years postoperatively (T1), and >4 years postoperatively (T2). These images were used to measure the frontal angle, anterior skull base ratio, and bone defect area.

Results: This study included 11 patients in the 1-piece group and 9 patients in the 2-piece group. The relapse ratios of the frontal angle were -2.3% ± 0.6% and -4.9% ± 2.1% in the 1-piece and 2-piece groups, respectively, showing that the 2-piece group had a significantly higher relapse ratio ( P = 0.002). At the T2 period, the 1-piece group had a significantly higher anterior skull base ratio (0.80 ± 0.10) than that in the 2-piece group (0.69 ± 0.08, P = 0.046). In addition, the bone defect area was significantly lower in the 1-piece group (T1: 4.90 ± 2.32 cm 2 , T2: 2.55 ± 1.57 cm 2 ) than in the 2-piece group (T1: 10.74 ± 5.89 cm 2 , T2: 5.35 ± 2.74 cm 2 ) both at the T1 ( P = 0.037) and T2 ( P = 0.025) periods.

Conclusions: One-piece FODO can result in the preservation of the bone segments' vascularity and the enhancement of osteogenesis in the distraction gap. Moreover, 1-piece FODO is associated with lower rates of relapse of deformity and bone defects compared with 2-piece FODO. Lastly, 1-piece FODO can be performed to maximize the advantages of distraction osteogenesis and improve surgical outcomes, especially among early childhood patients with BCS.