[Ultrasonography for traction injuries of the brachial plexus]

Results of preoperative ultrasonography (US) were compared with the subsequently offered operative findings retrospectively on 35 ventral rami of the cervical nerves (11 C5, 11 C6 and 13 C7) in 12 patients injured in motorcycle accidents in order to examine the usefulness of US in the diagnosis of nerve injury. The findings of a US-scanned ramus consisted of shape, internal echo pattern, regularity of border, and ratio of the diameter of an injured nerve to that of the corresponding nerve on the intact side (I/C). An intact ventral ramus was shown as a hypoechoic tubular structure with many parallel fine linear internal echoes, a regular border, and I/C ranging from 1.0 to 1.2. Categories such as I/C and shape improved the accuracy of differential diagnosis of severe nerve injuries. Avulsion of the ganglion was observed as a winding or tadpole-shaped remarkably enlarged (2.3 < or = I/C < or = 5.0) mass lesion, intraforaminal lesion as a thick (1.5 < or = I/C < or = 3.2) structure with an irregular shape and border close to the transverse process, and pseudocontinuity as irregular internal echoes. It was difficult to discriminate a lesion with continuity and localized scar formation around the nerve from normal fasciculi. These results strongly suggest that the application of improved US diagnosis to cervical nerve injury should make it much easier to select the best treatment for the patient, in that we can detect preoperatively those injuries to which nerve transplantation is not applicable.