Wrist and hand

De Quervain's tenosynovitis

Mechanism: Thickening of the tendon sheath of the first extensor compartment, where the abductor pollicis longus and extensor pollicis brevis tendons run over the radial styloid. Repeated gripping with ulnar deviation is the usual load.
Recognition: Pain over the radial styloid on thumb movement and lifting, and a positive Finkelstein test: thumb in the fist and the wrist in ulnar deviation.
Course: Notably common in the first year after childbirth, probably from the combination of lifting with the thumb abducted and hormonal changes. Here too there is no inflammation histologically but thickening of the sheath.

Structures