Scaphoid kinematic behavior after division of the transverse carpal ligament.

PURPOSE: The effect that carpal tunnel release (CTR) has on scaphoid motion has not been reported. Accordingly the purpose of this study was to determine the flexion/extension behavior of the scaphoid during global wrist radial/ulnar deviation before and after division of the transverse carpal ligament (TCL).

METHOD: In this study we examined the in vitro kinematics of the scaphoid during wrist deviation in 6 cadaver forearms both before and after the division of the TCL using a computerized camera monitoring system. The specimens were evaluated in 13 different positions, from 20 degrees of radial deviation to 40 degrees of ulnar deviation at increments of 5 degrees.

RESULTS

The data indicate that the difference in scaphoid position after TCL division is statistically significant when the wrist is in ulnar deviation of 15 degrees or greater. In addition a significant difference in scaphoid extension between pre- and post-TCL division conditions was found at 5 degrees of radial deviation as well as at 5 degrees or more of ulnar deviation and increased with increasing ulnar deviation.

CONCLUSIONS

Scaphoid kinematics are altered considerably in radial-ulnar deviation after division of the TCL. This alteration may have long-term consequences and contribute to commonly seen post-CTR symptoms.