Purpose or Case Report: Premature infants are at an increased risk of physical abuse. However, the rate of classic metaphysical lesions (CMLs) in premature infants is currently unknown. Therefore, the aim of the current study was to compare the rates of CMLs in premature infants relative to term infants.
Methods & Materials: Using the radiology information system, a one year (2003) retrospective study is being conducted using initial radiographic skeletal surveys performed in children under two years old at Riley Hospital for Children. Of the 657 infants that had skeletal surveys, preliminary analysis was performed on 100 patients (performed in reverse chronological order). Clinical information was obtained from the radiology reports and the electronic medical record. The proportion of clinically diagnosed abuse and the proportion of fractures and CMLs between groups were compared using Fisher's exact tests.
Results: Of the 100 patients, 34 had no documented birth history. Of the remaining 66 patients, 17 had a history of prematurity. The mean gestational age at birth in these premature infants was 34 weeks, 5 days (with a range of 27 weeks, 6 days to 36 weeks, 6 days).

29.4% (5/17) of premature infants were clinically diagnosed with nonaccidental trauma, whereas 35.3% (6/17) had an indeterminate clinical diagnosis. On the other hand, 51.0% (25/49) of term infants were clinically diagnosed with nonaccidental trauma, whereas 14.3% (7/49) had an indeterminate clinical diagnosis. There was no difference in the proportion of abuse between these groups (p=0.12).

Premature infants had fractures on 35.3% (6/17) of skeletal surveys with CMLs present on 5.9% (1/17), whereas term infants had fractures present on 32.7% (16/49) of skeletal surveys with CMLs present on 8.1% (4/49).There was no difference in the proportion of fractures in general (p=1.0) or CMLs specifically (p=1.0) between these groups. No CMLs were present in patients with accidental injuries or with an indeterminate diagnosis.
Conclusions: These pilot data indicate that premature infants may not exhibit higher rates of fractures or CMLs. Given the current limitations (small sample size and no difference in the rate of clinically diagnosed abuse), though, the larger study incorporating the stage of prematurity and corrected gestational age will be needed to validate these findings (and the updated results will be presented). Future studies will incorporate followup skeletal surveys and examine the specificity of CMLs in premature infants.