In 1974, Los Angeles Dodgers pitcher Tommy John was having a dream season until he tore his UCL, the ligament that supports a pitcher’s arm while throwing. Following a creative surgical procedure, John recovered and went on to play 14 more seasons, forever changing the game. Today, an astonishing 35% of active MLB pitchers have had “Tommy John surgery.” But it’s not just major leaguers; about 60% of athletes who’ve had the surgery are under the age of 19. Correspondent Faith Salie looks at how a surgical procedure has changed how people view repetitive sports injuries.