Late i know but now 15 months post MFX patella, was back in gym after 8 months MFX has done wonders for me no pain, no giving way, only issue is when i am tired it ACHES !!!! unfortuantly i now has issues with left knee, and terrible pain in left hip, that first started day one after getting on crutches. Doc says its arthritis...... not a day goes by when it does not hurt. Lately tho ive been waking up middle of night and hip has locked, i am shouting out in pain !! untill i can straighten my leg out ...... referred to hospital lets see whats the next plan of action is.......