Casement window operating arm

It looks like you need a new hinge, though I'm afraid I can't make out what you have based on this photo. Is it at all possible to see an undamaged version? Either the top hinge or from the hinge on another window? Can you also tell me how long the base track is? Please write out the length in your response; a photo of a tape measure will not be sufficient in this case.

Thanks! This is a huge help. Looks like a pretty typical casement window hinge. I suggest our 36-048. The design is going to be a little different, but it will work as long as the base track is 10" and as long as you replace the top and bottom at the same time.