Will One Be Able To Sit In Comfort After A Hip Surgery?

My Brother's doctor has recommended the Girdlestone surgery on his hip, due to failure of his hip replacement. Will he be able to sit in a chair or is the hip joint going be to stiff? He is 63 yrs. old, 6 ft. tall and weighs 279, is in horrific pain in this hip and the other, which has yet to be operated on.