Background: Carpal tunnel release (CTR) has been shown to change carpal arch morphology. However, the effect of CTR on the three-dimensional kinematics of the carpal bones has not been demonstrated.
Purpose: This study examined whether release of the transverse carpal ligament (TCL) would alter the three-dimensional kinematics of the carpus, specifically the bony attachments of the TCL.
Methods: The in vitro kinematics of the carpus was studied in five fresh-frozen cadaveric wrists before and after CTR using three-dimensional computed tomography. The specimens were evaluated in three positions: neutral, 60 degrees of flexion, and 60 degrees of extension.
Results: The data indicate that carpal arch width increases significantly in all positions after CTR as measured between the trapezium and hamate. Second, the trapezium-hamate distance increases in both a translational and rotational component after CTR. Additionally, the pisiform rotates away from the triquetrum after CTR.
Conclusions: Carpal kinematics is significantly altered with a CTR, especially on the ulnar side of the wrist.
Clinical relevance: Although the kinematic changes are small, they may be clinically significant and potentially responsible for pillar pain or postoperative loss of grip strength.
Keywords: carpal arch width; carpal bone contours; carpal kinematics; carpal tunnel release; transverse carpal ligament.