Bam Margera's Doc Told Him Legs Were 'Rotted Rubber Bands' Because of Booze

Bam Margera says he was lost for a while ... and, a doctor even told him his legs were totally shot -- but, he's come all the way back in the new Tony Hawk game.

We caught up with the former "Jackass" star and skate legend Tuesday ... and, he talked about what it means to be in the game -- which comes out this week -- and Bam's super excited.

Bam notes he's gone through hard times over the last decade -- full of drug and alcohol abuse as well as several notable arrests -- and, he credits his wife Dannii Marie for helping him build the necessary strength back in his legs to get back on the board.

In fact, it's shocking Bam's skating at all again ... 'cause he says a doctor referred to his legs as "dry-rotted rubber bands" due to alcohol abuse in 2013.

Bam shared a couple behind-the-scenes vids to his Instagram ... including a series of his own faces on a computer screen for the new game -- and, he told us he was blown away by the realistic look of this game.

ICYMI ... Bam told us back in April he'd actually missed the deadline to be part of the new game -- so, we had to ask how he made this work. Bam's got two words for us explaining his inclusion: Tony Hawk. We guess when your name is on the game, it's hard to say no!