Fig. 11.

Complications after carpal tunnel surgery. Transverse (a, b) and sagittal (c) sonograms obtained over the median nerve in a patient with previous local surgery and persistent paraesthesia. Axial sonogram (a) obtained at a proximal level shows a bifid median nerve consisting of a large radial component (large arrowhead) and a small ulnar component (small arrowhead). More distally, the radial component of the nerve shows a focal hypoechoic enlargement of its medial portion (black arrowheads) associated with a blurred fascicular pattern. A sagittal sonogram obtained over the pathologic nerve (dotted line in b) shows a focal in-continuity neuroma (black arrowheads). Note the normal proximal and distal nerves (asterisks)