Undertaker was spotted on crutches in late 2016 due to having surgery. The surgery was a temporary fix of his hip. He is in good health right now but will eventually need major hip replacement surgery. It is said that he is putting that major surgery off until retirement, and WWE is hopeful that no complications come from it. It appears that Undertaker will retire after this year’s WrestleMania, although he has said that so many times before.
Source: Ringsidenews