Serial plain films of the pelvis showing ONFH progression from (A) April 2013 (flattening of right femoral head [Steinberg stage IV]; normal on left), (B) February 2014 (reduced joint space; sclerosis and cysts on the right [Steinberg stage V] and minimal collapse without flattening on the left [Steinberg stage II]), and (C) April 2018 (prosthetic right hip and sclerosis without flattening of the left femoral head [Steinberg stage II]).