Can old, cruddy cleats cause knee pain?

[zia]

More knee pain... 'tis the season!

I've had my bike for ~6 months now and spent the money on a good professional fitting with someone I trust. I've been biking many miles quite happily.

Until 2 1/2 weeks ago. Midway on a flat ride: horrible knee pain on the upper outside of my knee.

I'm a reformed masher, but I wasn't mashing and I wasn't going up any big hills. I took 2 weeks off the bike, was able to run 5 miles without pain, and then... Sunday... got on the very flat bike path, and the pain returned. I skipped the nice hill loop I had planned. :/

When my mentor had knee pain, she went to her fitter, who quickly figured out a crack in her shoe sole was the source of her problem. New shoe, no pain. My cleats are from 2002. They are from my mountain biking days and are pretty beat up. And when I turned the left (problematic) one over, I discovered the little clip-in piece (forgot the correct name for that) was caked in mud, probably from a rainy race I did. I can't believe I was even able to clip in.

Picture is below. It's hard to tell, but the mud is thick in there.

Before I park the children with a sitter and drag myself 30 minutes back to the fitter, does anyone think this mud could be causing all my problems? It's just so strange that I've been fine for so long (doing up to 40 mile rides) and suddenly be crippled... grrr... But I sure do like the idea of new shoes.