Using sprites doesn’t necessarily mean you need to define them in css backgrounds. You can also use IMG tag sprites, to do so you need basically trim your image. There are two good articles explaining that technique:
http://tjkdesign.com/articles/how-to_use_sprites_with_my_Image_Replacement_technique.asp
http://www.artzstudio.com/2010/04/img-sprites-high-contrast/
Both CSS and IMG methods sure have their own benefits, so you need to figure out which one suits you better.