TENDOVAGINITIS is not tenosynovitis. The three primary causes of stenosing tendovaginitis are occupational stretching of the tendon, repeated active contraction of the muscle moving the tendon, and direct injury, the stenosis being the residuum of a gross blunt injury. Before there is stenosing tendovaginitis, there must be nonstenosing tendovaginitis. It takes time to make a sheath stenotic. The latter is reversible, the former is not.
I. STENOSING TENDOVAGINITIS OF THE FIRST DORSAL COMPARTMENT
De Quervain's disease is the stenosing tendovaginitis of the abductor pollicis longus and the extensor pollicis brevis tendons at the level of the styloid process of the radius.The recent literature has emphasized the anatomical variations in the tendons of the first dorsal compartment and the clinical variations of stenosis influenced by the anatomical variations. Loomis1 (1951) described five variations which may be reduced to two: 1. There is stenosis of one or both