Military docs attempt to salvage limbs using amputation as last resort. The guys that elect to remove the limb state afterward it was the best decision and wish they had gone that route for recovery much earlier. Of course the guys I work with have injuries more critical than arthritis.
Make the decision to amputate based on improvement of quality of life and not some quest for athletic glory. A new set of probllems arise- poor fitting prosthetics, infections, blisters, possibly lasting for weeks with no ability to wear a leg. Then there is the cost of a walking leg, a running leg and a sprinting leg as they are all different. Running as a single leg amp is much more difficult than having both legs removed because while one articulates naturally the other is mechanical and not as balanced. The gait of an above knee amp is awkward because there is no kneed joint.
However, if you are in China you will have no choice as that is how they field their Paralympic team.