The injury was announced just hours before what would have been her first public event since being hospitalized last month. The Queen had planned to attend a ceremony for Remembrance Day, a day that commemorates fallen members of the armed services, much like Memorial Day in the US.
The 95-year-old royal, who joined the Auxiliary Territorial Service during World War II, was reportedly "disappointed" to miss it. The Remembrance Day ceremony has consistently been part of her schedule, and a royal biographer told the Associated Press she considers it one of her most important events every year.
In her place, Prince Charles laid a wreath on her behalf at the Cenotaph in London.
In recent weeks, the Queen's health has been the subject of concern.
Last month, she was reportedly hospitalized for medical tests and "reluctantly" canceled a planned trip to Northern Ireland after doctors advised her to rest. She also did not travel to the UN Climate Change Conference, COP26, in Scotland, appearing instead by video message to urge leaders to act now for future generations.
In a press conference Sunday, Prime Minister Boris Johnson said he saw the Queen on Wednesday and "wanted to reassure everybody" that she was "very well."
Next year, the Queen will mark her Platinum Jubilee for an unprecedented 70 years on the British throne.