Sounds like the same injury that caused me to forego a career in a certain American pasttime involving large individuals colliding into each other every 30 secs.
I also have/had a congenital narrowing of the spinal column and a cracked vertabra to boot.
Just last night I was doing RDLs at 335, so there is hope. Don't despair! Needless to say I don't do deads anymore, still back sqaut (albeit lighter), and still do heavy front squats. I believe it's all in what your comfortable with.
For me it took some time off from anything heavy lowerbody training (read: lots of body weight trainging), TONS of core and stability work, and losing weight (at the time I was 325, playing weight). Too this day, I maintain core and rehab training intergral in my training.
Number one rule: Listen to your body, and swallow your pride. You don't want to end up in a situation that severly hampers you down the line. (Side note: I was too the point of losing feeling in my legs...). Lift smart, and be cautious.
The doctors also told me I should never squat again, but then again if I listened to them all the time I would have missed out on some great opportunities. To each their own, and good luck.