The `American Idol` host underwent a "procedure" after filming the show on 28.03.12 as he needed treatment to remove scar tissue from an old tendon injury.
He revealed on twitter: "I have a tiny tear in my elbow-pausing life for procedure."
He later explained during his KIIS-FM show: "I had a probe stuck into my right elbow. I`m not a robot [but] they went in with a tiny little probe and they scraped some scar tissue from the tendon, cause I tore the tendon from working out."
Ryan - who admits he is "not a great patient" - was wide awake during the surgery but admits he couldn`t bear to watch what the doctor was doing.
He said: "I couldn`t look. But I could feel the pressure.
"It was very easy and practically noninvasive."
While the procedure went well, Ryan hadn`t expected it to take so long and ended up with a schedule clash.
He said: "I didn`t calculate suturing into my schedule. I thought it was an in-and-out, 12-minute procedure."
The 37-year-old star later tweeted a picture of his arm showing where he had been treated.
Alongside the image, he wrote: "Will this be noticeable in my mesh falcons jersey? funny bone not so funny today.(sic)"