Prevalence of metaphyseal injury and its mimickers in otherwise healthy children under two years of age

BackgroundMetaphyseal lesions in infants and toddlers are believed to have a high specificity for inflicted injury.ObjectivesTo examine the prevalence of metaphyseal injury and its mimickers in otherwise healthy children younger than 2years of age.Materials and methodsDuring 2010-2015, all children 2years old and younger seen at the Accident and Emergency (A&E) Department due to an injury who had radiographs taken were included. Information on mechanism and clinical findings were drawn from the medical notes. All radiographs were reviewed by two of five researchers together with an experienced paediatric radiologist, registering fracture site and type, and metaphyseal appearances.ResultsFour hundred and eight children (212 boys) (mean age: 17.7months, range: 3-24months) were included, of whom 149 (77 boys) had a total of 162 fractures (incidence of 5.4 per 1,000 children). Only one metaphyseal lesion, without a history of trauma, was seen. Of the 860 metaphyses analysed, 140 (16.3%) were defined as either irregular (74/860, 8.6%) or as having a metaphyseal collar (66/860, 7.7%). Sixty-four of the 66 collars (97.0%) and 54/104 irregularities (60.8%) were located around the wrist and the ankle, while 25/74 irregularities (33.8%) were found around the knee joint.ConclusionMetaphyseal lesions with a history of trauma did not occur in otherwise healthy neonates and infants younger than 2years of age, indicating that this type of fracture has a particular trauma mechanism. Metaphyseal irregularities/collars are frequently seen and should not be mistaken for a classic metaphyseal lesion.