I had a partial knee replacement (left knee, lateral) back in early January 2015. It is now late October and I still have difficulty navigating stairs (both up and down) and still experiencing persistent soreness. Stepping unexpectedly on uneven terrain where one step is 1/2 inch lower or higher than the previous one can bring about sharp twinges of pain. Most articles on partial knee replacements say that recovery takes 6-8 weeks. Even if I were a slow-healing patient, don t you think 9 months is excessive for recovery (although I haven t recovered yet)? As it is, I am active and a very physically fit individual. So I don t understand why I haven t healed from the surgery.