Thanks everyone. I appreciate every bodies suggestions. It is all a part of my eventual decision.
I have lived with a partially fused ankle for over 40 years now, from a botched attempt to correct a club foot. I have long since learned to deal with significantly limited mobility and near constant pain in the joint, but as I have gotten older the pain has become more severe.
I am not thrilled that the only solution the surgeon can come up with is complete fusion, which might eliminate the pain, but would certainly eliminate the already severely limited motion I now have, completely. OK, I'll save that "final" option till there are no others, thanks Doc.
In the meantime I am scheduled to consult a pain Doctor that can either soften the pain, or possibly burn the pain nerve. I am combining this approach with doing ankle development work with my martial arts instructor, which has produced limited but welcome relief.
Having always had to deal with a partial fusion I have found that the angle of the blade on split fins provides better thrust, but have to be put on either in the water, or at edge of boat, as there is no way I can lift my toes, to walk in the one fin.
Again, Thanks!