Kaley Cuoco nearly lost a leg after a severe horse-riding accident during 'The Big Bang Theory'

Kaley Cuoco's longtime tenure as Penny on The Big Bang Theory was nearly marred by tragedy in 2010 when the actress suffered a major horse-riding injury that almost led to an amputation of her left leg. The story is detailed in a new book written by Jessica Radloff (now on sale from Grand Central Publishing) chronicling the definitive history of the smash hit CBS sitcom, which ran for a total of 12 seasons between 2007 and 2019. The actress can most recently be seen in the new time travel dramedy Meet Cute, streaming on Peacock.

"That was the darkest, most frightening time in all 12 years [of the show]," recalled Big Bang Theory co-creator and executive producer Chuck Lorre (via People). "Kaley could have lost her leg. It was a series of miracles that allowed us to get through that and for her to come out the other end of that healthy."

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Doctors initially surmised that even with the best care and an optimistic prognosis, the actress wouldn't be able to walk for several months after the fact. As it turns out, Cuoco was back on her feet two weeks later (aided by a walking boot, of course) and only had to miss two episodes of the show.

"Before I went into surgery, they made me sign something that said, 'We don't know until we get in there and see this leg, and it could come out that you don't have it anymore.' That wasn't the case, obviously, but I had to sign something that said, 'OK, you can,'" Cuoco said. "Everything ended up fine, and I was up and working a week later, but the doctors acted like I was never going to walk again. It's still too much for me to go into, and it sounded way worse than it was. And of course it was spiraling and everyone was freaking out, which I get. It scared people."

A good chunk of the credit for this miraculous recovery can be chalked up to Dr. Stephen Lombardo — a leading member of the Kerlan Jobe Orthopedic Clinic for Sports Medicine at Cedars-Sinai. After a fortuitous encounter with Lorre immediately following the accident, he made sure Cuoco went under the knife two hours later with the best experts overseeing the procedure in order to stop the spread of infection "because her leg was wide open," he said.

"It was an absolutely miraculous intervention that I ran into Dr. Steve," Lorre explained. "Every time I see him, I say, 'Thank you! You saved Kaley! On a lesser level, you saved The Big Bang Theory!'"

Cuoco can currently be seen in Peacock's time-traveling rom-com, Meet Cute, alongside Pete Davidson. The actress has also signed on to play the lead role in the streamer's upcoming true crime comedy series, Based On a True Story, which hails from executive producer Jason Bateman.