Pediatric Skull Fractures Contacting Sutures: Relevance in Abusive Head Trauma

OBJECTIVE. The purpose of this study was to assess the incidence of pediatric skull fractures contacting cranial sutures in abusive versus accidental trauma. MATERIALS AND METHODS. A retrospective review was conducted of head CT studies performed for pediatric head trauma at a free-standing tertiary care children's hospital from 2012 to 2019. Statistical odds ratios were evaluated to assess the significance of skull fracture extension to sutures in abusive versus accidental injury. A two-proportion Z-test was used to determine the statistical significance of suture type contacted by skull fractures in accidental versus abusive injury. RESULTS. The records of 47 children with 57 abusive skull fractures and 47 children with 54 accidental skull fractures were evaluated. The patients were 1-36 months old. Fifty-one abusive skull fractures (89%) terminated in contact with a cranial suture; 35 of the 51 (69%) touched two or more sutures, and 12 touched three or more sutures. Forty-two of the 54 (78%) accidental skull fractures contacted a suture; only 3 of the 42 (7%) touched two sutures, and none touched more than two sutures (odds ratio, 28.4 [95% CI, 7.6-105.9]; p < .001). In the abusive fractures, the suture most commonly contacted by a fracture line was the lambdoid (43%; p < .04), followed by the sagittal (23%), coronal (21%), temporal-squamous (12%), and metopic (1%) sutures. There was no statistical difference in which suture was contacted by fracture lines in accidental cases. CONCLUSION. Skull fracture contacting cranial sutures is common in abusive and accidental pediatric head trauma. However, that a fracture contacts two or more cranial sutures is an imaging finding not previously described that has a significantly higher association with abusive than with accidental head injury.