» Introduction
First dorsal compartment tendonitis, more commonly known as de Quervain's tendonitis or
tenosynovitis after the Swiss surgeon Fritz de Quervain, is a condition brought on by irritation
or inflammation of the wrist tendons at the base of the thumb. The
inflammation causes the compartment (a tunnel or a sheath) around the tendon to swell and
enlarge, making thumb and wrist movement painful. Making a fist, grasping or holding
objects (often infants) are common painful movements with de Quervain's tendonitis.
What causes it?
The cause of de Quervain's tendonitis is an irritation of the tendons at the base of the thumb,
usually caused by taking up a new, repetitive activity. New mothers are especially prone to
this type of tendonitis: caring for an infant often creates awkward hand positioning, and
hormonal fluctuations associated with pregnancy and nursing further contribute to its
occurrence. A wrist fracture can also predispose a patient to de Quervain's tendonitis,
because of increased stresses across the tendons.
