5/3 2:39 PM PT -- Doug's attorney, Marty Singer, tells us, "As a result of the pending criminal proceeding of Natalie Sutton's violent assault and battery of Doug Reinhardt, there will be no comment by Mr. Reinhardt at this time."

'The Hills' star Doug Reinhardt was sitting on a couch -- on the mend from a serious knee operation -- when his drunken wife grabbed his metal crutch and gave him a beating ... law enforcement sources tell TMZ.

Natalie Sutton was arrested early Saturday morning in Paradise Valley, AZ and charged with felony assault and battery. Our sources say she and Doug had gone to dinner and returned to their hotel. He sat on the couch where he was recovering from an ACL operation when Natalie suddenly went ballistic, grabbed his metal crutch and began swinging, targeting his bum knee and head.

Doug was injured and bloodied. He called the cops, they arrested Natalie on the spot for the attack. She was released later Saturday and ordered not to go near him.

We've learned Doug filed for divorce on Monday. They married last October.

You may recall Doug had dated celebs in the past, including Paris Hilton and Amanda Bynes. He got engaged to Allie Lutz, but they never married.

Looks like it's time for another fresh start.