Steve-O broke both of his legs in a skateboarding accident.
The Jackass star was attempting a stunt in which he stood on top of a wooden structure that a car plowed through and while his first two attempts went well, a third try left him with a number of broken bones.
Steve, 42, explained on Instagram: "I broke my right ankle in three places, dislocated it, and broke my left heel."
He also shared a picture of himself in a hospital bed and wrote: "I really did a number on myself today. Apologies in advance for the images of my foot sticking out sideways - wish me luck in surgery!"
It hasn't been a good year for the stunt performer - whose real name is Stephen Gilchrist Glover - as it was revealed in March that he and Kat Von D had split up after three months of dating.
And last year he was charged with five misdemeanours, including vandalism and creating a false emergency, after setting off fireworks from a 100ft construction crane in Hollywood in a protest against marine mammal park Sea World.
He was then ordered to serve 30 days in jail after reaching a plea deal with prosecutors.
He pled no contest to trespassing and possessing fireworks, and was placed on probation for three years.
He was also ordered to stay out of Hollywood temporarily and pay $14,000 in restitution fees to the city, as 80 firefighters and 30 police officers responded to the incident.
Following the hearing, he said: "Considering I've become a clean and sober, dog-rescuing vegan, I must say I'm ready to go to jail - not just because it will bring so much attention to the plight of orcas in captivity, but because it's nice to let people know I haven't lost my edge. What can I say, I'm a jackass."
The judge, who dismissed three other charges against the star, also banned him from owning fireworks and ruled he must secure a permit before performing any more stunts.
- Bang! Showbiz