The transverse carpal ligament: anatomy and clinical implications.

The anatomical characteristics of the transverse carpal ligament (TCL) have recently been further clarified. Its bony insertion sites proximally to the scaphoid and pisiform are more round, whereas the distal insertion sites to the trapezium and hamate are more oblong, with reproducible areas of insertion. The thickness of the TCL varies along the path of the median nerve, with the thickest portions distal ulnarly and proximal radially. The predominant fiber orientation is transverse. This more detailed understanding of the anatomy of the TCL may enable more novel treatments of carpal tunnel syndrome.