He says: "I will be turning this into a walking cane, skin the flesh off it, then
the foot becomes the handles and just add a bone to make the full
length"

This is youtube user "Donsfoot." He answers some questions and elaborates more about how he's going to make his cane on his youtube page. Among them:

-- He injured it on the job and it was causing chronic pain, so he had it amputated

-- As to how he was allowed to keep it, he says "I just asked the Surgeon, Was told it mine just to pick it up when i go home"