My husband had a terrible time healing with his hip replacement...He spit the stitches....Saying this I know what you are going through...YES, you could be allergic to the prostesis...Recently we added a new large walk in shower in our master bathroom...This was being done in view of the surgeries...The man who did the estimates and arranged for the contractors, told of us problems with his surgery...He had to have a second surgery performed with another type of prostesis...

I believe that the one leg being longer is going to be problems...This could be the reason for the pain and not the prostesis...They will probably have to do the other hip to even this off....Hopefully this may help you....Years ago my husband had to have his seoond knee replaced three months later as it was bothering his hip....Kind of makes sense...

Good luck...

Caroline