Hi,
It might be arthritis. I was diagnosed with PCa nearly 4 years ago and at the same time got an intense pain in the hip while I was on a country walk but managed to get back to the car which was 4 miles away. It was agony and for 2 days after I couldn't walk. Then I couldn't bend down for some time. Very slowly it got better, over a period of 6 months.
Although that was not fast enough for my imagination. Also not helped by searching the internet and of course finding people whose first symptoms were a pain in the hip.
The doctors and nurses kept telling me the bone scan found nothing and people associate every pain with PCa when usually it has nothing to do with it.
Anyway after my op I decided to go to the GP saying it was Trochanteric Bursitis but might be related to PCa He laughed and said it was likely to be arthritis and gave me Ibuprofin gel and just in case said I could have a psa test. Which was undetectable. I used the gel a few days but couldn't imagine it would help so didn't use it.
It went away completely after about 6 months.
Your husband might have something else but it might be arthritis.
I also get a pain right down my left leg every few months since the op. I think it's the sciatic nerve, I read the op can shift it. Wow that is painful. Luckily it only lasts about 10 seconds a time.
Let's hope for the best
Peter