Detection of Differential Gliding Characteristics of the Flexor Digitorum Superficialis Tendon and Subsynovial Connective Tissue Using Color Doppler Sonographic Imaging

Abstract

The subsynovial connective tissue (SSCT) is the most characteristic structure in the carpal tunnel and is substantially affected in cases of carpal tunnel syndrome. We investigated the usefulness of Doppler sonography for measuring velocity differences between the flexor tendon and its associated SSCT in the carpal tunnel of cadaver hands. Six human cadaver wrists were used in this study (mean age of death, 82.2 years). The velocity difference between the middle finger flexor digitorum superficialis tendon and its corresponding SSCT was measured on a sonography machine equipped with a fingertip 13-MHz linear probe. At tendon velocities of greater than 2.5 cm/s, the tendon velocity was significantly greater than the SSCT velocity (P < .05). At less than 2.5 cm/s, there was no significant difference between tendon and SSCT velocities. Color Doppler imaging can identify and track SSCT motion separately from that of its associated tendons. Analysis of SSCT motion characteristics by color Doppler imaging may be useful for studying its function clinically.