Burgharts sign, also known as the "pistol grip deformity", refers to a condition characterized by the abnormal appearance of the thumb and fingers in a hand affected by severe rheumatoid arthritis. Synonyms for Burgharts sign include "rheumatoid hand deformity" or "swan-neck deformity", as it resembles the graceful curve of a swan's neck. This deformity is caused by the erosion of joint tissues and tendons in the fingers and thumb, resulting in a flexed middle joint of the finger and hyperextension of the outermost joint. The name Burgharts sign pays tribute to the pioneering work of Dr. Michael Burghart, who extensively studied hand deformities in rheumatoid arthritis patients.