The star was taken to hospital after a lighting rig fell and struck her head, and she was forced to take time out from shooting the show before finally returning last Friday.
She had previously only revealed she had suffered a "serious head injury" but it's now emerged the actress had a five-and-a-half-inch crack to her skull.
Chenoweth tells the New York Daily News, "I had a huge tarp lighting fall on my head and it knocked me out. It slammed me back and my head fell on the curb, so I've had a five-and-a-half-inch skull fracture." (ZN/NYDN/PAW)
