Classic Metaphyseal Lesions among Victims of Abuse.

Objective: To use legal statements by perpetrators to gain new insights into the causative mechanism of classic metaphyseal lesion (CML). The CML, so called "corner fracture," is considered a highly specific marker for abuse in infants. However, the precise correlation between CMLs and abusive head trauma is still unknown.

Study Design: In this retrospective observational study, we selected 67 cases with at least 1 CML from a 15-year cohort of legally prosecuted child abuse cases. Their clinical, radiologic, and forensic records were analyzed. In 27 cases, the perpetrator confessed to abusing the child and described the events. Potential associations with subdural hematoma and with confession were evaluated using 2 separate binary logistic regression models.

Results: All 67 infants showed other signs of abuse. Median age was 3.4 months. Over 65% had multiple CMLs. Knees and ankles were predominantly involved (64%). Only CMLs of the shoulder were significantly associated with subdural hematoma (P = .03). Different-age fractures were more common in the nonsubdural hematoma group (P = .01). In the group with confessions, perpetrators admitted inflicting violent indirect skeletal forces (torsion, traction, compression, and forced movements). The most common circumstance was diapering (44%), reported by male perpetrators only (P = .03) followed by dressing/undressing (30%). The violence was habitual in 67% of cases.

Conclusions: This unique forensic case series shows that CMLs are caused by violent acts inflicted most during physical care of infants. The frequency of habitual violence responsible for CMLs deserves greater attention.