What birth defect did Lord Byron suffer?

George Gordon Byron (later Noel), 6th Baron Byron, FRS (22 January 1788 – 19 April 1824), commonly known simply as Lord Byron, was an English poet and a leading figure in the Romantic movement. Among his best-known works are the lengthy narrative poems Don Juan and Childe Harold's Pilgrimage, and the short lyric "She Walks in Beauty".

From birth, Byron suffered from a deformity of his right foot. Although it has generally been referred to as a "club foot", some modern medical authors maintain that it was a consequence of infantile paralysis (poliomyelitis), and others that it was a dysplasia, a failure of the bones to form properly. Whatever the cause, he was afflicted with a limp that caused him lifelong psychological and physical misery, aggravated by painful and pointless "medical treatment" in his childhood and the nagging suspicion that with proper care it might have been cured.