So, my protagonist, who is a general in his late twenties (this isn't terribly unusual according to the society's norms, but that's a different subject), is leading his company in a medium-scale dogfight that's just above a mountain range. His craft is shot down with a device that shuts off all power upon contact, so upon crashing it doesn't burst into flames. But my question is, how exactly can he survive this crash and lose the use of his legs without suffering paralysis? I'm assuming it has to be a pretty bad multi-fragmentary fracture, but I want the right amount of breakage so that it's only moderately repairable (to get the shape back, at least), but not so much that his legs have to be amputated. His other injuries include several cracked ribs and a mildly fractured hand. Aside from perhaps affecting his breathing for a while, I'm not sure these injuries would be of terrible significance.
Later in the story he starts traveling on a luxury spaceship that uses artificial gravity (thus mimicking standard gravity like we feel on Earth). He gets around in a hoverchair, but also undergoes physical therapy for his legs. How will being in artificial gravity affect how his legs heal? Is there anything that can be done to prevent severe atrophy?
The main thing is, I really don't want him to heal. Any hope of him getting back to normal, or even being able to walk again, would diminish the character development he really needs. I just need to determine the exact circumstances involved in his injury that will allow for this.
I researched bone fractures on various websites, including Wikipedia and WebMD, and also looked up physical therapy for broken legs on Google (although the results all involving recovery, and I doubt most of those fractures were this severe). I have also discussed artificial gravity and severe leg fractures with some of my friends, but I'm looking for the most conclusive answer I can get. Thanks very much for all your help, and I sincerely apologize for any bads on my part.