Katy Perry has pieces of rocks in her knee

Katy Perry has traces of rocks stuck in her knee after a series of childhood scrapes while surfing in Santa Barbara, California.

The Firework hitmaker, 28, showed off her odd injuries during an appearance on The Tonight Show with Jay Leno on Friday (26Jul13) and admitted she has no intention of going under the knife to remove the stones from beneath her skin - because she's grown to love them.

She explained, "Growing up in Santa Barbara I did a lot of surfing and skating and wherever I go I still have these two rocks that I still can't get out of my knees from being slashed across the rocks in Rincon, which is like a really popular spot in Santa Barbara, and the rip tides just slapped me against the rocks and forever I've had these rocks in my knees...

"I kind of like it, I feel, like, closer to earth."