Iphone 4s with broken screen and i have a passcode?

I broke my iphone 4s and the screen is cracked and won't allow me to put pass code. So what can do do back up my iphone? Itunes won't recognize the iphone if i won't put passcode

Ask a mechanic to replace screen and backup after that. No other way.

Just replace the screen, here is lot of choices for you

You will probably need to replace the screen. I cracked mine a couple of weeks ago, and I was not prepared to pay apple to fix it. I found iscreensfix.com, they sell repair guides and videos. So I ordered a new screen, followed their guides and videos and had my new screen up and running again. Worked perfectly!