Fig. 3.

Wrist: infiltration of anesthetic and cortisone into the synovial sheath of the extensor tendons of the wrist (first compartment) for De Quervain’s disease. A) US image performed in the axial plane shows the 25-Gauge needle (white arrowhead) situated in the soft tissue and evidences hypoechoic thickening of the tendon sheath (black arrow) associated with synovial effusion (asterisk) surrounding the mesotenon (mes) and partially the two tendons (1 and 2). B,C) Sequential images showing the tip of the needle piercing the sheath and approaching the fluid collection. D) Image showing the steroid solution spreading in the synovial effusion (black arrowheads) during US-guided injection.