I must say to say that an implant "slipped a little" makes no sense to me unless he was trying to hint that it had loosened, which would not be a good thing. Likewise, "reshaping" the replacement also isn't something that is done. There is no reshaping the hard metal implant nor the plastic insert. And any "reshaping" of bone would be a surgery that would likely involve replacement of one or more components of the implant.
I don't want to worry you, but it always amazes me when surgeons leave this type of impression with a patient that just a "nip and a tuck" here and there can eliminate problems if they arise. It would be very, very helpful if you could supply whatever xray was taken at your last visit here so Jo could take a look. If the implant shows signs of loosening, she'll see it.
All that said, if whatever discomfort you have is not constant, it is possible that it's more a soft tissue matter than a problem with the implant itself. Please keep us updated on how you're doing!