Fig. 2.

Ultrasound monitoring of the ultra-minimally invasive carpal tunnel release. A axial view: hook knife position (arrow) between the median nerve (M) and ulnar artery (A) and below the transverse carpal ligament (arrowhead); the curved line represent the space expand with local anesthetic between the carpal tunnel ligament, the flexor tendons, the hook of the hamatum and the median nerve. B Longitudinal view positioning of the hook knife (arrow) at the distal cutting point below the TCL (arrowhead). C longitudinal view pulling back on the hook knife (arrow) while applying volar pressure for retrograde releasing of the TCL (arrowhead). D ultrasound control of the TCL release. Double arrow represents the free edges of the TCL that have been cut releasing the median nerve (NMedian). Bone landmarks; H is the hook of the hamatum, C is the capitatum