We dont kniw exactly what happens in our bone process after fracture. I always thinking about this. I broke my talus undisplaced body fracture. I went to several doctors all of them said to wear a cast for 12 weeks and it will heal in a cast no need surgery. I couldn't find exact information people who healed with cast after talus fracture. I am in a cast now with no weight bearing. I did Ct scan and two X rays. Doctors did not tell me anything about risk of arthritis and osteonecrosis. Once I asked from one doctor about risk of avn in my fracture. He said that will not happen and it will heal well. But after I read many forums about this bone I feel in a depression. Can I run again, can I hike again like before? please give suggestion
We do know what happens in our bones when they heal. Bone healing is called knitting and you’ll want to have good nutrition and possibly PT afterwards to learn good movements and get some range of motion back properly. The hard part is that all of this takes a long time and many of us get depressed during the process. Once the cast comes off you will have to “learn to walk” again. It’s painful but the best thing to do is get back to using it. Go for walks. It feels better after use. I had a trimalleolar fx and it was displaced. Good news is that non displaced is better and it’s something to feel good about in your recovery. This whole process takes more mental strength than physical, in my opinion. This forum helped me immensely. Toss and concerns you have put here, it’s very helpful. Also, people sometimes share the horror stories more than the good ones so just know that. Ask to hear the good ones too, specifically. I just had my hardware removed about a month ago and I went for a run, and bicycle rides, and I walk with almost no pain. You will get there with time 
I am almost12 weeks post op and I am walking and back at work. I wear ankle support and my flat shoes (no high heels). I walked both of my big dogs around my neighborhood twice so far. I’m still a little sore but the swelling is minimal if I don’t over do it. I am also 56 years old, so there is hope! I didn’t have a cast, instead I had a boot which I no longer wear. I have two plates, 8 screws and a tightrope fixation, fortunately I won’t need them removed unless something weird happens. I did however pay out of pocket for rehab and am doing what’s called “strain and counterstrain physical therapy” it has worked wonders for me thus far...Good Luck and stay positive.