Prevalence and distribution of occult fractures on skeletal surveys in children with suspected non-accidental trauma imaged or reviewed in a tertiary Dutch hospital

Purpose: The purpose of the study was to determine the rate of occult fractures (without clinical symptoms) per presenting clinical injury i.e., children presenting with a fracture, bruise, abusive head trauma and the types of fracture most likely to be found, in a series of infants and young children suspected of being victims of NAT. Methods: Skeletal surveys done between 2008 and 2018 of children (< 5 years) were retrospectively analyzed. Both radiographs of admitted children and reassessment images from all over the country were included and reviewed by a forensic paediatric radiologist. Deceased children were excluded. Variables as gender, age, initial clinical injury and occult fractures were collected. Occult fractures on the follow-up skeletal survey were collected. Results: A total of 370 skeletal surveys of 296 children were included. Median age was 22 weeks (IQR 11–48), there were 172 (58%) boys. A total of 195 occult fractures were detected in 111 (32%) children. Occult fractures were detected in 37/126 (29%) children with fracture as presenting symptom, 33/90 (37%) children with head trauma and 26/50 (52%) children with bruises. Rib (n = 56, 50%) and lower leg (n = 40, 36%) fractures were most detected. Conclusion: Occult fractures were detected in 32% of the children. Occult fractures were most prevalent if the initial clinical injury suggestive for NAT to request skeletal survey was a bruise, abusive head trauma or fracture.