Frontal Bone Resorption after Frontofacial Monobloc Advancement in FGFR -Related Craniosynostoses: Predictive Factors.

Abstract

Frontofacial monobloc advancement (FFMBA) with internal distraction is a key procedure in managing FGFR -related craniosynostoses. Resorption of the frontal bone flap can occur months to years postoperatively. This study aimed to identify clinical factors associated with the extent of frontal bone resorption in patients with Crouzon or Pfeiffer syndrome. A retrospective single-center study was conducted on children with Crouzon or Pfeiffer syndrome who underwent FFMBA between May of 2008 and October of 2021. Computed tomography scans were analyzed at 4 points in time: early postoperatively (before distraction), at the end of distraction, 2 years after surgery, and, optionally, 5 years after surgery. Variables examined included demographic data, genetic mutation, prior craniofacial procedures, presence of tracheostomy or ventriculoperitoneal shunt, indication for FFMBA, perioperative parameters (osteosynthesis type, advancement, or surgery duration), and postoperative parameters (cerebrospinal fluid leak, infection, distraction protocol, or retrofrontal dead space). A total of 63 patients were included (mean age, 2.91 ± 1.61 years). At 2 years postoperatively, the mean frontal bone resorption was 4.83 ± 5.35 cm² (range, 0 to 27.3 cm²). Significant factors associated with increased resorption included use of absorbable sutures compared to steel wires (9.83 versus 3.99 cm²; P = 0.04) and the presence of a retrofrontal dead space at 2 years (13.12 versus 3.63 cm²; P < 0.001). Frontal bone resorption following FFMBA is significantly associated with the use of absorbable sutures and persistent retrofrontal dead space. Rigid osteosynthesis should be favored, and distractor activation should be performed with follow-up of brain expansion. Risk, III.