The actress and theatre star hurt her shoulder during training, and has now been told by doctors that scans show she has three bone fractures as well as a partial dislocation, which means she cannot skate with partner Matt Evers in the TV competition while she recovers.
Denise announced the news on Instagram, writing that she was "gutted" to be leaving the ITV show early, but explaining the situation with fans.
"If you've been watching @dancingonice you will be aware that just over a week ago I had a nasty fall and injured my shoulder," she wrote.
"I managed to skate my first dance with @themattevers on the live show through a gritted smile because the pain was unbearable.
"I've tried as hard as I can to carry on because I love the show and the amazing team in front and behind the cameras.
"Initially we thought with rest I could make a return to the ice, but a recent MRI scan has shown that I have 3 bone fractures as well as a partial dislocation. OUCH! No wonder I've been in agony."
She continued: "I won't be able to do any lifts, tricks or solo skating on the show due to my injury.
"I'm going to bail out gracefully with my DOI bling sling."
Writing a special tribute to her skating partner, Denise signed off: "@themattevers has been the most incredible support and skate partner (a true friend) and I'm so grateful for his expertise in teaching me (ice virgin) the basics.
"I just wish I was well enough to learn all the fabulous tricks my injury won't allow me to do. Chair dancing on Ice with a massive pie won't get us points on the leaderboard.
"I'm actually proud of what I've achieved (not much, lowest scores so far) . If you don't mind I'm going to give myself a couple of points for bravery for doing cartwheels on Ice at 46 with broken bones.
"I wish all the celebs, pros and judges the best of luck for the rest of the series. I'm rooting for you all. Bunch of legends #dancingonice2021".
Alongside her statement, Denise shared a glitzy picture of herself and Matt, as she pointed at the sparkly cast on her arm.
Matt Evers also shared a statement of his own. "Denise has worked so incredibly hard these past few months and I'm devastated that she's unable to show everyone what a beautiful skater she's become," he said.
"It's sad that the competition must end now for both Denise and I but it's most important that she takes the time to heal and recover.
"I loved our time on the ice together and I love the wonderful friendship that we will always have. I'm gutted to have Denise leave the show and equally gutted that last Sunday's hug will be my last for a while."
Meanwhile, a spokesperson for Dancing On Ice said: "We adore Denise and Matt and we're so very sad to see them leave the competition so soon.
"They are both much loved members of the Dancing On Ice family and we'd like to thank them for their hard work, from the moment they began training through to the joyful performances they brought to the show.
"We wish Denise all the very best as she now takes some time to make a full recovery."
With the pair's departure confirmed, a new couple will be stepping into the main cast.
Olympic gymnast Amy Tinkler is set to join the show alongside pro-skater partner Joe Johnson, from this weekend.
We'll miss Denise, but we're excited to see Amy in action!