Bartlett Pear Tree
One possibility is that the Bartlett part of the tree died back and you are left with growth from the rootstock. Callery pear (Pyrus calleryana) is sometimes used as a rootstock. It has small round fruit....and thorns, which Bartlett does not have.
You will have to look closely at your tree to see if this is the case.
Bill… thank you so much. I do believe you are exactly correct. I don't suppose there is anything I can do at this point? It's still a beautiful tree… but assuming it will never bare edible fruit again…?
If some of the Bartlett still remains you might be able to selectively prune to save it and systematically remove the rootstock suckers. See the attached photo. The green arrows indicate growth coming from the rootstock, which is the part below the graft union, indicated by the red line. The plant material above the red line, indicated by the yellow arrow is the Bartlett scion.
Your own situation may be different. It may be that your rootsuckers / watersprout emerge from the ground. If the graft union is below ground it is hard to tell what is coming from what. If you send me a picture or two I may be able to give you some more specific advice.