Ultrasound diagnosis of either an occult or missed fracture of an extremity in pediatric-aged children.
OBJECTIVE
To report and assess the usefulness of ultrasound (US) findings for occult fractures of growing bones.


METHODS
For six years, US scans were performed in children younger than 15 years who were referred with trauma-related local pain and swelling of the extremities. As a routine US examination, the soft tissue, bones, and adjacent joints were examined in the area of discomfort, in addition to the asymptomatic contralateral extremity for comparison. Twenty-five occult fractures in 25 children (age range, five months-15 years; average age, 7.7 years) were confirmed by initial and follow-up radiograms, additional imaging studies, and clinical observation longer than three weeks.


RESULTS
The most common site of occult fractures was the elbow (n = 9, 36%), followed by the knee (n = 7, 28%), ischium (n = 4, 16%), distal fibula (n = 3, 12%), proximal femur (n = 1, 4%), and humeral shaft (n = 1, 4%). On the retrograde review of the routine radiographs, 13 out of the 25 cases showed no bone abnormalities except for various soft tissue swelling. For the US findings, cortical discontinuity (direct sign of a fracture) was clearly visualized in 23 cases (92%) and was questionable in two (8%). As auxiliary US findings (indirect signs of a fracture), step-off deformities, tiny avulsed bone fragments, double-line appearance of cortical margins, and diffuse irregularity of the bone surfaces were identified.


CONCLUSIONS
Performing US for soft tissue and bone surfaces with pain and swelling, with or without trauma history in the extremities, is important for diagnosing occult or missed fractures of immature bones in pediatric-aged children.
Cho
Kil-Ho
KH
Department of Diagnostic Radiology, School of Medicine, Yeungnam University, Daegu 705-717, Korea. khcho@med.yu.ac.kr
Lee
Sung-Moon
SM
Lee
Young-Hwan
YH
Suh
Kyung-Jin
KJ
D000293:Adolescent; D050280:Arm Bones / Q000000981:diagnostic imaging* / Q000293:injuries; D002648:Child; D002675:Child, Preschool; D005260:Female; D050723:Fractures, Bone / Q000000981:diagnostic imaging* / Q000628:therapy; D006801:Humans; D007223:Infant; D007867:Leg Bones / Q000000981:diagnostic imaging* / Q000293:injuries; D008297:Male; D011859:Radiography; D014463:Ultrasonography