"I've been trying so hard to get fit for today but had to accept this morning it wasn't going to happen," Dettori said in a statement to Ascot racecourse.
"I've got to have physio and get it properly looked after so won't be at Ascot this week.
"For me that's soul-destroying as it's the most important week of the year. I'll be counting the days until next year," the 46-year-old added.
The British-based Italian rider sustained the injury in a paddock fall at Yarmouth, eastern England, last Tuesday but was passed fit to ride Shutter Speed in the French Oaks on Sunday.
But Dettori said the injury was still troubling him, meaning he will miss all five days of the Royal meeting, one of the highlights of the English racing calendar, which starts on Tuesday.
He had four rides on the opening day alone, including favourite American speedster Lady Aurelia in the King's Stand Stakes.
The ride on Lady Aurelia -- who stormed home by seven lengths in the Queen Mary Stakes under Dettori last year -- is taken by American legend John Velazquez.
The 45-year-old has also been given the nod by Lady Aurelia's trainer Wesley Ward for the prized mount of Nootka Sound in the final race on the card the Windsor Castle Stakes.
Velazquez, who has won the Kentucky Derby twice as well as the Belmont Stakes among other big race successes, originally had just the one ride another of Ward's runners in the Windsor Castle Elizabeth Darcy.
Elizabeth Darcy will now be ridden for 49-year-old Ward -- the first American to have trained a winner at Royal Ascot back in 2009 -- by Edgar Prado.
Dettori's ride on another American challenger American Patriot in the opening Group One Queen Anne Stakes has also been snapped up by Velazquez.
Three-times the champion jockey in Great Britain, Dettori's best-known achievement came at Ascot on September 28, 1996, when he won all seven races on that day's card at the Berkshire course, southwest of London.
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