The 23-year-old British singer was forced to cancel a series of summer shows after slipping off stage during rehearsals in June, and said that the injury has been one of the worst things to happen to her.
'I've had to have full reconstruction. I've had my bone taken out and someone else's put in,' she told The Sun. 'I hope they were a tap dancer.
'I don't know when it's going to be fully healed, or if I will ever be able to wear heels again. I'll have to get an endorsement deal with a trainer company.
'I have days where I sit and cry. It's the hardest thing I've been through. I should have really spent the last three months at home but I couldn't turn down the VMAs and Glastonbury. The doctor keeps telling me to rest.'