I'm currently in remission for osteosarcoma. I had my peroneal nerve removed due to my tumor. I suffer from severe, permanent drop foot also. From what I've been told, there is nothing you can really do to regenerate the nerve if enough of it is gone. After a certain amount is cut...it will not grow back. I hope in your husband's case he still has enough left to have some function. I can only move my foot downward a little, not up at all since I have practically no control over my ankle whatsoever, and I have no control over my toes at all. I also constantly feel as if my foot is asleep.
I highly recommended the Swede O Step foot brace. It actually lifts up your foot as you walk, instead of just remaining flat like a regular AFO. My father in law is a podiatrist, that is how I found out about this...and it's been a life saver! Or perhaps if he has enough nerve, the WalkAide would work for him, it's a device you wear around your leg that sends a signal to the brain to make the peroneal nerve work. It would not work on me since I have no peroneal nerve at all.
My oncological orthopedic surgeon wants to do a tendon transfer after I am a year out of chemo. So, they do that for some cases! It would not give full function back, but would keep my foot at 90 degrees all of the time, which is much better than simply hanging there.
Does your husband have trouble wearing shoes? I find I can only get on sandals that have a back and two straps up front by myself because I am able to put my brace down a set my foot right into it since I have no function. Wearing regular shoes is impossible!
I hope he recovers at least somewhat. Let me know if you need any information!