Interesting, I had heard almost the same thing about MM's injuries that his hands were broken like you said during the unfortunate events that took Np's life, although this is the first time I am hearing he needed surgery to fix them. This however would fit with the theory of why they went to London for medical attention because London has some of the best doctors to repair hand injuries. When one of my ex's son rolled a car on his arm and severed the tendons in 2 places, yea it was a MESS, the Dr. in London was able to repair and reattach the tendons in both places.
JMO but I think this makes a good fit to the story line, but I guess we will find out once everything is released during the trial.