Dynamic changes of the transverse carpal arch during flexion-extension of the wrist: effects of sectioning the transverse carpal ligament.

The width of the carpal arch, represented in this study by the distance between the tips of two Kirschner wires--one inserted into the trapezium and another into the hook of the hamate--was measured with precision calipers in 21 patients with carpal tunnel syndrome, both before and after sectioning of the transverse carpal ligament and in different wrist positions. With the ligament intact, most of the wrists showed a decrease in the distance in both flexion and extension. The distance increased an average of 11% after sectioning of the transverse carpal ligament. The dynamic behavior of the carpal arch, however, was not substantially modified by this procedure.