Courtney Boles told her children Buddy the elf had fallen and broken his leg.
Boles uploaded a photo to Facebook of Buddy wearing a cast on his leg, with the caption: "He has strict orders from Santa not to move for two weeks. Parenting win!"
Boles' children woke up in the morning to see Buddy the elf's leg cast with a note that read: "Oops! I fell off the star last night and broke my leg.
"Never fear, Santa set me up with a cast in my favourite colour. He also gave me STRICT orders not to move for two weeks to let my leg heal.
"In the mean time, Santa will be coming here to get his nightly report.
"That means you MUST go to bed when your parents say so you don't chance Santa seeing you! Sincerely, Buddy the Elf."
The photo, which was uploaded on 3 December, has been shared 31,000 times.
The majority of the parents commenting saw the funny side of the post.
"You guys are pure geniuses," wrote one person.
"You my friend deserve a reward. So trying this! Being the third Christmas it gets harder coming up with fast things to do," commented another.
However Boles said she also received some negative comments, asking "what's the fun in that", so she decided to explain why she did it.
She told TODAY Parents: "My four-year-old son has autism and has a hard time following the rule about kids touching him [the elf], as clearly stated in the book, so I am limited in my options on where he can move.
"Also, we were headed out of town for my daughter's soccer tournament and my younger daughter and son were staying with grandparents.
"Instead of trying to come up with an excuse why Buddy wasn't coming, we decided he should break his leg."
Boles said her daughter has been making Buddy 'get well soon' cards daily and her oldest daughter takes a daily selfie with him.
Buddy the elf will be back causing mischief by 18 December.
If your elf hasn't broken his leg and you're in need of some ideas to see you through to the end, click through the slideshow below.