I'm now 10 months post THR surgery and still having the thigh pain although sometimes it is much worse than other times for no apparent reason. I'm also able to "walk it off", meaning the pain is worst when I first stand up and lessens as I walk for a couple minutes.

I got a 2nd opinion from a different surgeon who also had no clue and seemed annoyed that I would even feel the need to get a 2nd opinion. Like "Go away, you are throwing a monkey wrench into our assembly line." After doing my own research I found a Mayo article that seems about right but who knows. It can be found by googling "Ipsilateral Inflammatory Neuropathy After Hip Surgery".

It's basically talking about inflamed nerves in the surgical leg occurring about a month post-op and not caused by physical damage to the nerve during surgery and which can be helped by use of immunotherapy drugs. The study is about 10 years old so you'd think there would be more current info but this is the best I can do for now.