What Causes Persisting Pain In The Knee Post Shingles Infection?

I had shingles twice this last year and had pain along the inner part of my shin the first time and the outer part of my knee the last time. I have been having pain in the outer knee again and have been taking an anti-viral as a precaution, but he knee pain is still there. Is this lingering nerve pain? (I have been on Gabapentin for over a year for a bulging disc in my neck) You would think I would have no pain at all!