Pope Francis has had three hospitalizations since he was elected pope in 2013, and underwent major surgery as a young man to have part of one lung removed.
In between, the 86-year-old pontiff has suffered from bouts of sciatica, or nerve pain, that have made walking and standing difficult. More recently, he strained his knee ligaments and had a small fracture in one knee that have forced him to use a wheelchair and walker for over a year.
