I saw the surgeon on Tuesday. I have a new "plaster", which I will have to wear for at least another four weeks.
The new plaster (resin, instead of PoP) seems to allow a little more movement - the "end joint" of my thumb is now free. I can't bend it much, but am going to see a specialist hand therapist soon (I hope), who will help me work on it. My wrist is still held rigid.
The surgeon seems to think that the bone will heal okay and knit together. I made need another op to remove the titanium plate at some point.
This is a huge relief. There is little I can do now except wait for the plaster to come off and see what movement I have.
I am genuinely touched by the responses in this thread. Thank you all so much. It has meant a lot to me, and truly helped me. In the moments when I have felt the most down, I have remembered comments posted here, and it has helped me stay positive.
Thank you.