Long-Term Results in Isolated Metopic Synostosis: The Oxford Experience over 22 Years

BACKGROUND: Metopic synostosis causing trigonocephaly is treated by fronto-orbital advancement and remodeling to correct the deformity and cerebral distortion and to treat intracranial hypertension in a small number of cases. The aim of this study was to evaluate complications, revisions, and long-term outcomes. METHODS: A retrospective chart review was performed on consecutive metopic craniosynostosis patients treated between February of 1995 and February of 2017 at the Oxford Craniofacial Unit. RESULTS: Two hundred forty-five patients with isolated metopic synostosis were seen. Two hundred two patients underwent fronto-orbital advancement and remodeling. Fifty patients were girls and 152 patients were boys. Mean age at surgery was 16.8 months. Mean weight preoperatively was 12 kg. All patients received blood transfusion. Mean postoperative stay was 6 days. Average follow-up time was 8 years (range, 0.5 to 22 years). There were eight major complications (4 percent). Six patients (2.9 percent) required secondary calvarial expansion for late raised intracranial pressure. Thirty-one (15 percent) had other subsequent procedures, including wire removal and forehead shape contouring with alloplastic onlay. Raised intracranial pressure before surgery was confirmed in two cases by intracranial pressure monitoring. CONCLUSIONS: Trigonocephaly is caused by metopic synostosis and is treated by fronto-orbital advancement and remodeling to restore both internal and external skull configuration. After surgery, the authors identified a 2.9 percent risk of late raised intracranial pressure requiring a secondary calvarial expansion, necessitating prolonged follow-up in all cases. Temporal hollowing and forehead contour defects were not uncommon. This is the largest reported series of metopic synostosis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.