The dancer was preparing for this week's Dancing With The Stars tenth anniversary celebrations when the accident happened.
US-born Derek shared a picture to Instagram showing himself pulling a sad face while sitting in a wheelchair, although he later deleted it. Fellow dancer Mark Ballas said: "Long night in the ER with Derek Hough. Nothing worse than seeing a fellow dancer get hurt, especially your brother."
So far, there's been no word on what sort of injury Derek suffered. A rep for DWTS would only say he was injured during rehearsals. His dance partner Maria Menonous suggested the injury was caused by a chair, sharing an image to Instagram of herself glaring at a chair.
Derek alluded to his injury on Instagram last night, sharing the inspirational message: "Your setback is a platform for your comeback."
Get well soon Derek!
Derek was mentioned frequently in Cheryl Fernandez-Versini's autobiography. They were widely rumoured to be in a relationship following her split from Ashley Cole, but she's always said they were just good friends. She credited Derek in the book for helping her cope following the split and aiding her recovering from Malaria. She'd actually been in Tanzania on holiday with Derek when she fell ill.