I'm very sorry to hear of your dad's pain. I've just been researching the Girdlestone procedure because one of the patients in our hospital just had it done. On average, in different studies, about 74% of patients are either completely or almost painfree after. What I wanted to pass on is that some of them go on to have a total hip replacement done after they're healed, on average 13 months after the Girdlestone. This is considered the best option for a painfree functional outcome. Has that been considered for your dad? If you're into research, you can use pubmed at the top of this page. Put in Girdlestone, or excision arthroplasty hip, or resection arthroplasty hip, and you'll come up with quite a few article titles. You could pick and choose what seemed to fit your dad's situation best. Good luck to him.