Traumatic tenosynovitis of the wrist extensors is a common and disabling condition associated with overuse. It has been found to be associated with hypertrophy of the bellies of abductor pollicis longus and extensor pollicis brevis where they overlie the radial extensor tendons in the forearm, compressing these tendons and their enveloping paratenons against the deep structures beneath. Simple surgical decompression of the sheath of these overlying muscles has been found to give quick relief of symptoms and to allow a more rapid return to strenuous work than the conservative treatments usually employed.