The Owen Burrows-trained five-year-old beat last year's Coronation Cup winner Pyledriver and High Definition last Friday in impressive style.
Hukum required surgery after picking up the injury during the race, but Burrows confirmed it was "serious but not career-ending".
There was a serious weight of money for the Shadwell Estate Company-owned colt at the Coronation Cup, who raced in those colours made famous by Hamdan Al Maktoum.
There was little or no pace to the contest for much of the way which would have helped the winner, as once it became a sprint he was always well placed both in terms of his handy position in the field and his obvious pace over this sort of trip.
A previous Group 3 and Group 2 winners, he ran on strongly throughout the final quarter-mile to win by a decisive margin of over four lengths and get his name on the Epsom roll of honour.
"He's got a fracture in his hind leg so we've had to put some screws in it. Obviously he'll be out for the rest of this year," said Angus Gold, racing manager for owners Shadwell Estate.
"It's a shame as he'd just won his first Group One with a career-best.
"We haven't got as far as deciding if he will return to training as it's early days.
"From one point of view he just seemed to be hitting his best form so with that in mind you'd say yes, but at the same time he'll be a back-end five-year-old this year.
"We haven't had a chance to discuss that and won't make a rushed decision as he'll be in his box for a bit.
"We'll make a decision on that later in the year.
"It's a real shame, sadly, especially for Owen as Friday was a huge result for him, but you've got to take the rough with the smooth."