Not all for the same reasons but all have resulted in the same outcome, contracture with aggressive scar tissue, flexion and extension issues. Each time was an attempt to stablize, change design of the implant or because it became loose. Soft tissues are pretty messed up, after one surgery I ended up with a focal Dystonia that required quarterly Botox in quads and hams that took 18 months to resolve. Now after 7 years of this and my good leg doing all of the work, my good leg is showing signs of arthritis and there are times I can barely walk for the pain and stiffness. I’m pretty discouraged