de Quervain's Tenosynovitis

de Quervain’s tenosynovitis results from inflammation of the tendons of abductor pollicis longus (APL) and extensor pollicis brevis (EPB) at the radial styloid process. It occurs from repetitive wrist twisting (eg, screwdriver, thumb movements on a mobile phone). The Finkelstein sign is a key clinical exam finding. Thickening of the extensor retinaculum over the first dorsal compartment irritates the tendons of abductor pollicis longus (APL) and extensor pollicis brevis (EPB). The tendon sheaths of APL and EPB are irritated by the overlying extensor retinaculum.

• Wrist twisting movements (using a screwdriver, racquet sports, even thumb stretch movements on a mobile phone, or game-controller use).
• Lifting activities (eg, lifting a frying pan).
• Trauma
• Post-partum state, due to wrist swelling (also a cause of carpal tunnel syndrome) and due to wrist twisting to hold a neonate.

The Finkelstein test is a provocative maneuver that can produce first dorsal (extensor) compartment tenderness. It involves thumb adduction and flexion with ulnar-deviation (medial deviation) of the wrist. Wrist splint, anti-inflammatories, steroid injection.