Hi Chimeara, Its a difficult decision to have to make, however, if the pain has not been relieved by other methods (painkillers etc) then hip replacement is usually the treatment of choice.
This is because the affected portion of the bone consists of the head (the ball-shaped piece of bone that fits into the socket of the hip) and neck (the portion of the thighbone just below the head). When it’s deprived of blood, this part of the bone begins to “die,” breaking down and causing the cartilage on top of it to collapse.
He will be in hospital for about 2 weeks with that and have lots of physiotherapy.
As for your worries about the upstairs toilet etc, do not worry about this. When he has had the procedure he will be assessed by Occupational Therapy. They will sort all of that out for you and assist in getting you other means of help that you may need when dad comes home.
This will all be sorted before your dad goes home.
As for the memory loss, that could be down to medication. If he is on powerful painkilling drugs it would account for this.
I wish you well, try not to worry =)