Time and deterioration are not going to be in your back pocket on this one. I feel the opinion saying to undergo the procedure now, while you may be in the best position you'll ever be, the most robust and capable of rehab working for you, is the most reasonable one. You'll just continue to decline just on the basis of the passing months, let alone anything else lurking that you don't know about. Why not jump at the best opportunity you may ever have?