The use of modernizr with rotate3d in IE9

Question

I am working on a site that uses

.item:hover{
    -webkit-transform: rotate3d(0,1,0,-180deg);
}

to flip div on hover.

This now needs to be supported in IE9, i was going to use modernizr to check for support:

if(!Modernizr.csstransitions) { 

}

And then implement the animation but can't get this to work, any suggestions or examples would help alot