Kevin Durant revealed some additional details on his surgically repaired right foot that went under the knife for a 3rd time back on March 31st, 2015. Before that most recent procedure, Durant's 5th metatarsal was in pretty bad shape.
It had a crack in it.
That's pretty normal when it comes to sidewalks and driveways. It'll make your skin crawl when it applies to someone's foot. Kevin Ding at Bleacher Report elaborated and got Durant to further explain:
Durant used a controversial bone-graft material that is not FDA approved for use in the foot to promote greater bone growth this time.