I find it really amazing that they remove the spurs thru arthoscopy.  I felt the same like you, knee would lock up and I had knee pain.  I had surgery last Friday (4/9/2010).  I had the recheck today, everything looks good and the stitches were removed and I can stop using the crutches.  Monday I start P/T.   The Doc suggested that I take the painkiller an hour before P/T.  I hope I can eventually stop limping.

I'm getting my LK repaired in June, same reason.  To be honest, I'm looking for to doing it and getting on with my life and hopefully pain free. 

This will be the 2nd repair on this knee (R) and in June it will be the 2nd for the other (LK).

I am not a doctor, but I just had tibial osteotomy (okay 10 weeks ago) because the inner portion of my knee is pretty much bone on bone due to some bowed legs and a lot of sports. 

When looking at the x-ray, you see what look like bone spurs that come just off the bone where the joint meets.  Doctor said that his is typical when two bones hit as it is a function of the bones hitting and looks kind of like the bone has literally been squeezed out and formed a little ridge around the joint.  He said that the tendons can catch on the spurs when they move causing irritation.

Once the problem is corrected, these spurs can go away as long as they are not hitting anymore.  We'll see.  Only 10 weeks into it and still have the external fixator.

My two non-doctor cents.

An update to my May 9, 2011 post on this topic.   A friend of mine who has different knee issues recently recommended aqua jogging as something that really strengthens the leg muscles w/o the pounding pain that comes from regular walking or running.  I tried it in the pool (it requires you wearing a flotation belt).  For the first several minutes I had a problem because periodically a tendon on the lateral side of my left knee would would catch when riding over the bone spur I described in my earlier posting.  That's a very uncomfortable feeling, and I thought I'd have to stop the aqua jogging.

Then the "twanging" went away!  I don't know whether I simply wore down the bond spur over time and repeated abration of the tendon against the spur or whether something else happened.  I suspect the former.  But since that day, I have had no real instances of the tendon being "caught" by the bone spur.  I periodically still feel the tendon rub over the spur, but it does not catch the way it did earlier.  My my orthopedic surgeon apparently was right about NOT going in to surgically remove such spurs (as a general rule).

I've only done aqua jogging once or twice since the first time, but I have never had the major bone spur issue return.  Se at least this is a "positive" development in my growing history of knee problems.