Changes in Carpal Tunnel Pressure Following Increments of the Carpal Tunnel Release

ABSTRACT

Complete division of transverse carpal ligament (TCL) is accepted as a standard procedure for carpal tunnel syndrome (CTS). In some cases however, after complete release of TCL, the loss of grip and pinch power occurs frequently. Previous study revealed that normal intracanal pressure is 25-30mmHg, therefore There were the possibility that complete division of TCL is an over-correction for CTS. The purpose of this experiment was to measure the carpal tunnel pressure during the incremental division of TCL. Twenty patients who were confirmed as CTS were selected from September 2002 to February 2003. By step-wise division of TCL, the pressure was obtained for 3 times serially. Comparative pressure changes between the pre-division and post-division were analyzed by SRM (standard responsiveness mean) and ES (effect size). In Carpal tunnel syndrome, the mean intracanal pressure was 215.5mmHg. After partial release of the portion which was revealed as most severely compressed area on inching test, the carpal pressure decreased to 70.6 mmHg. Releasing the remaining portion of TCL resulted in another 30% decompression. Effect size of partial release was 2.86, and after release of the remaining portion of TCL the effect size was 1.19. Comparing the effect size, as much effect as 70% of the total release (4.15) can be obtained by partial release.