Neonatal distal femoral physeal injury secondary to mechanical trauma of birth: A case report.

Physeal injuries occurring secondary to neonatal birth-related trauma are rare entities. Most reported cases of physeal injury involve the distal humerus with only a few published case reports of proximal femoral involvement. So far, we have found only one reported case of neonatal distal femoral epiphysiolysis following Caesarean section. We hereby report a unique case of distal femoral physeal injury with at least partial epiphyseal separation following an uneventful, spontaneous vaginal delivery. Given the uneventful delivery and no known prenatal risk factors, the imaging findings were initially not recognized as being secondary to birth-related injury. Nonaccidental trauma and infection were considered among the possible etiologies for the clinical and imaging findings and a detailed workup for both these entities was performed. Distal femoral physeal injury was considered as a diagnosis of exclusion only after both initial differential considerations were excluded. The authors hope that a knowledge of this entity will facilitate a more accurate differential in cases of thigh swelling and hypomobility in the newborn.