Heavy.com with the news:
Sources close to the event notified Heavy.com of the news this afternoon.
A compacted vertebrae was causing tingling in Aldo's arms.
This comes mere days after Aldo received the UFC featherweight championship from UFC president Dana White prior to UFC 123.
It currently is unknown what will happen with Grispi. I think it's safe to say there won't be an interim title fight here.