Elbow effusions in trauma in adults and children: is there an occult fracture?

OBJECTIVE: The purpose of this study was to evaluate whether a detectable abnormality was present on MR imaging without a visible fracture on conventional radiography in the setting of trauma. A recent retrospective study based on the presence or absence of periosteal reaction on follow-up radiographs concluded that fractures were not always present. The discrepancies in the literature over the usefulness of joint effusions as an indicator of fracture caused us to evaluate whether fractures were present more often than identified by conventional radiography. To do this, we used MR imaging.
MATERIALS AND METHODS: Thirteen consecutive patients (age range, 4-80 years; seven children and six adults), whose post-trauma elbow radiographs showed an effusion but no fracture, underwent screening MR imaging.
RESULTS: All patients showed bone marrow edema. Four of the seven children had fractures on screening MR imaging, and all adults had some identifiable fractures.
CONCLUSION: Preliminary data using screening MR imaging suggests that an occult fracture usually is present in the setting of effusion without radiographically visualized fracture.