Because of your repeated rejections most suggest scar tissue, but also consider this other cause.
I was scheduled for a knee replacement 4 years ago, but I have Allergic Contact Dermatitis, ACD, and although my skin patch tests which I had a decade earlier didn't test positve to metals I was surprised because I know I can't wear pierced earrings with nickel posts. I tested positive to over a dozen other contact allergens which were causing my internal and external inflamation based on the 5 Day Extended Patch Test kit by True Test. Before surgery I insisted on a current allergy test to test all the components. My surgeon said the best test would be a blood test which Medicare will not cover so I forked out $600.00 for a blood draw and my blood was sent to a lab in Illinois. It came back positive for 5 metals allergies , including the nickel allergen my patch test didn't identify, and even though I have several adhesive allergies I didn't test positive to the bone cement which many are allergic to.
Before any more surgery, get this blood test and also as many others have suggested get a second opinion.
I canceled my surgery. Athough I didn't test positive to a titanium allergy the surgeon told me there is no such thing as pure titanium, all mental implants have traces of other metals included some of the five I was allergic to. With wear these metals I am allegic to will seep out and my body will reject the implant. There is a ceramic coated implant on the market but the ortho explained with wear, over time, metals are released.