Miami-Dade Judge Michael Genden voided the verdict on Thursday. Attorneys for Dr. John Uribe had argued that there were fundamental errors in the May trial surrounding use of a medical manual as evidence.
McDuffie's attorneys had said the manual was properly used.
Both sides also argued over estimates that McDuffie lost millions in potential earnings because of the 1999 toe injury.
McDuffie originally was awarded $11.5 million, but that was later reduced to just under $11 million.
McDuffie played 116 games for the Dolphins from 1993 to 2000. He had 415 receptions for 5,074 yards and 29 touchdowns. He also returned two punts for touchdowns.