Grand National jockey Robbie Dunne is set for a spell on the sidelines after he broke his collarbone in a fall from 33-1 chance Stellar Story. The pair parted company at the 19th fence of 30 in the Randox-sponsored event on Saturday, won by the Willie Mullins-trained favourite I Am Maximus. Dunne was attended to by the on-course medical team when Stellar Story rolled onto him on the landing side of the spruce obstacle. Professionals came to his aid and he was taken to the nearby Fazakerely