"as worn as" is correct and usable in written English.
This phrase is usually used to describe a worn-out item or condition. For example, "The rug was as worn as an old pair of shoes."
Now, his knees are as worn as weathered lug nuts.
It was only when Corean was leaving that she noticed on a shelf behind the television a leatherette family Bible as worn as her own.
But with all the dangers posed by an 82-game season, I'm on my knees, which are as worn as Amar'e Stoudemire's from all my years of praying.
A fire burns in the living room hearth, surrounded by cracked leather armchairs as worn as the widewale corduroys and cashmere sweater Naylor wears.
The original seats and benches — slick, solid and comfortable — are nearly as worn as the lanes, and a small snack bar, about the size of most Manhattan kitchens, brings to mind a drugstore soda fountain.
As he chatted, Mr. Seeger broke into "Take It From Dr. King," which he wrote after the Sept. 11 attacks, in a voice as worn as an old phonograph record.
In any case, the experience, though neither as rich nor as wearing as it might have been, was instructive and, in many ways, novel.
Guy's depiction of the succession of convocations and parleys where this struggle was enacted could have been as wearing as the meetings must have been for the participants.
"I served in the Middle East, I served in Korea; and yet, none of it was as harrowing, as perilous, as wearing as the fight every day to push down, to keep inside the person that I knew that I was".
Her face was as creased and worn as old leather.
I have worn as many as four.
