Sounds like you are in the hands of an honest and very good orthopedic surgeon.
Chelation therapy is where a drug is either injected into a muscle, taken orally or -- the most common way -- given by IV infusion that binds to the metal. This drug/metal ion complex is then excreted by your body.
Currently the FDA is not recommending this therapy in cases like yours but some doctors are offering it.
Like anything else, it is not without risks: It can damage your bone marrow, kidneys, heart, cause a drop in blood pressure
, nausea, vomiting headache and, in some cases, even death.
Since the benefits of chelation therapy not known and the risks are very substantial most patients elect not to risk it.
I think your plan of removing the hip is a good one and I don't believe more extensive therapy is worth the risk. But, of course, this a decision only you can make.
Does this answer your question to your satisfaction?