The Usefulness of Dynamic Ultrasonography in Nursemaid's Elbow: A Prospective Case Series of 13 Patients Reconsideration of the Pathophysiology of Nursemaid's Elbow.

BACKGROUND

Nursemaid's elbow is a common musculoskeletal disorder among children under 5 years of age. However, diagnostic imaging to confirm a nursemaid's elbow diagnosis is still unavailable. Through the use of a high-frequency ultrasound probe, we determined the etiology and possible pathophysiology of nursemaid's elbow.

METHODS

Thirteen consecutive patients with the clinical suspicion of nursemaid's elbows were examined. A high-frequency linear array 6 to 24 MHz hockey stick transducer was used to detect small changes (partial eclipse signs) of the radial head in the axial view before and after manipulation.

RESULTS

All patients in this study had a successful reduction. A partial eclipse sign was found in all patients before reduction and disappeared after successful reduction.

CONCLUSION

These pathologic features detected through high-frequency ultrasonography suggest the role of the escaped posterior synovial fringe in the pathogenesis of the nursemaid's elbow. The specific finding of a "partial eclipse sign" could be a useful additional clue leading to the correct diagnosis of the nursemaid's elbow and may help avoid the unnecessary reduction in patients who do not have a "partial eclipse sign".

LEVEL OF EVIDENCE: Level II, diagnostic studies.