Purpose or Case Report: Proximal humeral epiphyseal fracture-separation is a rare fracture pattern in infants often associated with birth-related or non-accidental trauma, representing a Salter-Harris type I or type II fracture. Lack of a proximal humeral epiphyseal ossification center in most newborns or only subtle displacement of a small epiphyseal ossification center in older infants, makes this injury difficult to diagnose on plain radiographs, potentially leading to delayed diagnosis or misdiagnosis. Ultrasound and MRI are therefore useful imaging modalities in indeterminate cases.

Clinical findings of infant proximal humeral epiphyseal fracture-separation such as shoulder swelling, tenderness, and decreased active motion, overlap with more common entities including clavicular fracture, brachial plexus injury and osteomyelitis. Radiographs are often the first diagnostic study ordered to evaluate these symptoms but are insensitive due to minimal ossification of the proximal humeral epiphysis. Radiographs may be normal or show subtle displacement of the epiphyseal ossification center, apparent joint space widening, small metaphyseal fracture fragments or displacement of the proximal humeral metaphysis in relation to the scapula. These findings can be misdiagnosed as shoulder dislocation or pseudosubluxation due to a joint effusion. Careful review of the medical record may elucidate a history of difficult delivery with shoulder dystocia or suspected shoulder trauma.

Ultrasound and MRI are useful in indeterminate cases due to their ability to resolve the cartilaginous physis and proximal humeral epiphysis, and to resolve their relationship to the humeral shaft and cartilaginous labrum. Ultrasound has higher anatomic resolution and offers the flexibility to quickly image the asymptomatic contralateral shoulder and image in planes that best show the relationship between the non-ossified epiphysis and the humeral shaft. Doppler ultrasound demonstrates epiphyseal perfusion without the need for contrast administration, and serial ultrasound imaging can be used to evaluate healing and remodeling. MRI is more useful in evaluating cases where osteomyelitis and/or septic arthritis are being considered, or in cases of an inconclusive history suspicious for non-accidental trauma to evaluate for additional osseous and soft tissue injuries.

Several examples of typical proximal humeral epiphyseal fracture-separations in infants will be presented and the relevant imaging findings discussed.
Methods & Materials:
Results:
Conclusions: