When I was a kid, my mother often made "sirloin" steaks. They usually had either a round bone or a straight bone. I have not seen this cut for many years--the cuts of beef now called either "sirloin", "top sirloin" or "sirloin tips" is clearly different. For one thing, they come boneless. What was the cut of beef formerly known as "sirloin?" Is it still around (albeit under a different name) and why did it change (probably not because of contractual disputes)?