Doctor: I've got good news and bad news. First the bad news: You have a rare, incurable disease that the medical profession has never seen before.
Patient: Oh, boo hoo! And what's the good news?
Doctor: We're going to name it after you.
So maybe some poor guy called Claude was the first to be diagnosed with claudication. 
Actually I looked it up and it comes from a Latin word for "limping". And "limp" is somehow strangely relevant to prostate surgery!
After surgery, I had built up to a daily morning walk of about an hour. This is a serious walk, with many steps both up and down. No particular problems or undue stress. Then about day ten, after a half hour, I started to get an ache in my left thigh that got progressively worse. By the time I got home, I felt a considerable weakness there and had developed a limp. But after I sat down for 20 minutes with the leg raised, the ache and weakness disappeared and I was able to walk around normally the rest of the day -- but no long walks!
After this had been going on for a day or two, the urologist rang me with the results of my histology, so I asked him. He didn't know what the problem was, being mainly concerned about blood clots developing after the operation. A major symptom of this is swelling of the lower leg, which I didn't have.
I tried favoring that leg, and walking on the flat (no hills) and the problem still developed after about a half-hour. So I continued with my plan of seeing my usual doctor. He didn't waste time in diagnosing possible spinal claudication, and sent me for a spinal X-ray, which came back clear. I'd had a bone scan prior to the operation and that showed some "wear and tear" in the spine. My doc wanted to send me for a MRI scan, but the urology dept at the hospital, who have the final call on these things, said it was not necessary. So maybe that is a good sign.
Apparently spinal claudication is a common problem with old fogies like me, nothing to do with cancer, just degeneration of the spine, causing nerves to be pinched. Also it seems you can relieve the pain by leaning forward. I tried leaning forward, back, twisting side to side, and squatting (man, did those knees creak!), and none of that made an ounce of difference. Needless to say, I cut down the serious walking to half-an-hour at a stretch, until I felt the claudication just starting.
Then suddenly, about two weeks ago, the claudication vanished, almost as quickly as it arrived. I am now on serious daily walks of well over one hour and no sign of the problem again. On two days, I walked for a total of over three hours with some small rests, and still no problem.
So I'm not sure what the cause of it was. I've never had claudication before. I'm hopeful that it is not a metastasis starting in my spine (I've had absolutely no backaches). My theory is that is some strange side effect of the operation -- maybe something cutting off the blood supply to my leg nerves -- assuming nerves have a blood supply! I did come off pain killers about the time it started, but these were fairly tame Panadol and Codeine over-the-counter medications. These seemed very ineffective with the not serious abdominal pains -- maybe they were much more effective with the claudication.
Then today out of the blue, I got a call from the urology department at the hospital with an appointment for Monday, a referral from my doctor. So a big rush to get the PSA test done that I was due for -- originally "no rush". Now I have some PSA anxiety -- but as ever, I'm staying hopeful. Let's see what Monday brings.