Between Aerosmith projects and his long-in-the-works debut solo album, Steven Tyler has a busy year ahead. But he's also making time to go back under the knife.

"My knee is giving out," Tyler told Rolling Stone. "I had ACL reconstructions, and in November I'm getting knee replacement surgery. It'll take me about three or four months to recover ... I've had so many operations on my knees and feet that just to be standing is a miracle. But to turn around and do one of my spins where I don't fall, that's the s---! But hey, all these years have taken their toll on me."

In the meantime, fans can look forward to a new Aerosmith live DVD, 'Rock for the Rising Sun,' which collects performances from the band's 2011 Japanese tour, as well as -- at some point -- another new album from the band. All of which, he admits, makes things a little more complicated for Tyler the solo artist.

"It might be hard to decide when I write a song whether or not it should go on an Aerosmith album," Tyler explained. "What is a Steven Tyler solo album? Is it a bunch of songs like 'Dream On'? That's already on an Aerosmith album. It'll just be a different people playing it. I don't know. I just want to have some fun. I've got pieces of me that are a little bit more than Aerosmith. This gives me the freedom to write a song on trashcan lids or with the Boston Pops or an oboe and a harpsichord."

But that doesn't mean Tyler is walking out on Aerosmith anytime soon. "As long as I can sing, I'm up there," he promised. "I know Joe [Perry] wants to keep going. Remember, when one guy goes, it's not the original band. But as long as Joe and I wanna keep going ... Look, we just love to play. Without a doubt, when they colonize the moon, we'll be up there as a lounge act."