An expletive usually expressing disbelief or exasperation. It is the opposite to that of a Christian person saying ‘Christ on the cross.’ Somewhat akin to saying ‘Shit on a stick.’
“Christ on a fucking crutch, will you shut up and give me a break?!”
With a sigh and a shake of the head: “Christ on a crutch, I can’t believe how stupid this is.”
A more "embellished" phrase of the classic saying "Holy shit"!
An example of when to use it would be after excessive amounts of exertion to illustrate the mixture of exhaustion and lack of giving a crap about whats coming out of your mouth.
1) "Holy christ on a crotch! You almost got pancaked by that car!"
2) "Holy Christ on a Crotch, 'huff', thats a lotta stairs!"