AT PRESENT, stenosing tenovaginitis is a well-known entity. It occurs most commonly about the hand and wrist in the flexor tendon sheaths of the lesser fingers (trigger finger), in the sheath of the flexor pollicis longus, and in the sheath of the abductor pollicis longus and the extensor pollicis brevis. It has been observed, but more rarely, about the ankle and foot.1 The rather frequent stenosing of the common sheath of the abductor pollicis longus and the extensor pollicis brevis remained unrecognized until its classical description by de Quervain in 1895.2As pointed out by Finkelstein3in 1930, the condition was accorded scant recognition in the American literature and continued to mystify the physicians of this country during the first decades of this century, often being erroneously diagnosed as arthritis, neuritis, or periostitis. Although the modern orthopedic surgeon has no difficulty in recognizing and treating stenosing tenovaginitis,