Spinal injuries are the worst. Your ability to move your body depends on the nerves in your spine having an uninterrupted line to the muscle you want to move. If you injure your spine bones, you'll likely break this nerve and be paralyzed from that point down. The very idea of this scares the bejeebers out of me. (I thankfully am in a field that would allow me to work even if nearly totally paralyzed, but it would be much much harder.)
Thankfully, research has shown that a certain blue dye is helpful in reconnecting the nerves, so injury based paralysis may be a thing of the past. (As reported by biology student and generally awesome Blag Hag.)
But, there are other things that can go wrong. Someone in my family had a condition where the bones in his spine had their nerve-hole slowly close up until it pinched the nerve. In his later years, he moved very slowly, and had a bit of a hunch. This was hard on him, as before he was strong and athletic, with great posture.
For this condition, the usual treatment now is to cut open the spine bones and replace them with other, non-growing bones, typically a cadaver-donated thigh section. Eep. I'm going to try an artificial solution.
The spine needs rigid parts to shield the nerves from trauma, but also flexible parts in case the spine needs to move slightly. (Like if you're bowing, bending down to reach something on the floor, nodding, or the like.) The natural spine uses bone for the rigid part, and cartilage disks for the flexible part. Artificial replacements for the disks already exist. The 1337 MD would know better than me, but I think I would use titanium cylinders to replace the bone section. Titanium is very rigid, hard to bend, and should provide great protection to the spinal cord. If need be we can also attach fins to make it more like the natural spine. The ribs must also attach to this, probably pinned in place the way that a weak knee is often reinforced.
This artificial spine would be structurally stronger than the natural kind, but might have other disadvantages. I am not a medical doctor, so am unaware of what those disadvantages might be.