Three Dimensional Finite Element Analysis on the Morphological Change of the Transverse Carpal Ligament

Carpal tunnel syndrome (CTS) has been defined as an entrapment neuropathy of the median nerve. The high social and economic costs of carpal tunnel syndrome lead to a surge in the studies on it in these years. Although studies provide evidence that lengthening the transverse carpal ligament could be a possible alternative treatment for carpal tunnel syndrome, little is known about the effects of the mechanical properties of TCL on its morphological changes under mechanical loads. Based on CT scan images, a three-dimensional finite element model of the carpal tunnel modeled as a tunnel structure was constructed for the first time. The effects of different elastic modulus (100-500 MPa) and Poisson´s ratio (0.3-0.49) of the transverse carpal ligament on its morphological changes were analyzed using the present finite element model. As the elastic modulus increased, the arch height of the transverse carpal ligament decreased greatly. And the TCL arch height decreased much slower as the Poisson´ ratio increased from 0.30-0.40 than it did as the Poisson´s ration increased from 0.4-0.49.