Ok, just so everyone knows. The cubital tunnel is in your elbow and really what we are talking about is ulnar nerve entrapment, usually indicated by numbness in your little finger and the back of your hand. When it gets really bad, your little fingers will lose motor control and curl up. Carpel tunnel is an entrapment of the nerves in the wrist, usually causing numbness of your index, middle fingers and thumb and numbess in the palm. These are neuropathies and are made much worse by diabetes. When I looked into it, it seemed that as diabetic neuropathy sets it, there are several places in your body that are vulnerable to inflammation and entrapment, particularly your wrists, elbows and shoulders. Shoulder entrapment is something to be on the lookout for as well.
If you have not guessed it by now, I suffer from all of them (including shoulder entrapment). I have been through physio, but I am now to a similar point (primarily with my carpal tunnel), I am left with seemingly no option except surgery. I have to do something in the near future. My fingers are always numb, the numbness is spreading.
As to trigger finger, that is common problem, but of different character, probably more of a result of thickening of the tendons. Sorry I don't have that "yet."
It is my understanding the carpal surgery has markedly improved over the years. The success rate is now 70-90%. It is still recommended that you pursue less radical treatment before turning to surgery, primarily physical therapy, anti-inflammatories and using splints, particularly at night. There are bunch of expected complications, but generally not bad things. About 10% lose wrist strength.
I believe the open release method is the traditional method, leaving a scar from the open surgery. The newer technique is endoscopic, being just as effective as far as I can tell and leaving no major scar. My choice would be endoscopic.
I've not really looking into surgery for ulnar nerve entrapment, as my most pressing problem is the carpal tunnel. Do quickly move to try the physical therapy. Do exercises and get a brace for sleeping. Surgery outcomes are better if you don't wait around forever. But of course, it is not like I necessarily take my own advice.