I have had this knee condition where initially I couldn't walk without limping.
Then I found I had no balance control on my left knee when my left knee would bend forward while I put body weight on it.
I am able to walk properly now and do bit of running as well with knee support but still lose balance control on left knee if I am not careful. Also still get sharp pain in knee if climb stairs or decend stairs. Only way I can climb or descend stairs is when I put my right leg forward first followed by left leg. Climbing or descending by putting left first very painfull.
any help in getting correct diagnosis of problem is much appreciated