it does appear to be a dilemma.
i can't predict what your employer would accept from a medical standpoint to allow you to return you to work.
maybe they've already moved on and will not want to terminate your replacement even with a release.
is there someone in personnel/admin that you can talk to candidly? do you have a union?
it's difficult for me to believe your nursing career is that close to being over. there is a crying need for all kinds of nursing services--even in the bill review case/ management office type settings. health services employment is projected to continue to grow.
is there some additional training that might allow you to transition into a light work role?
work comp does offer a retraining voucher for those with PD
you might be able to get a more realistic view of your job prospects by talking to professional job counselor.
with herniated discs how long could you go before another incident/injury hits you?
you might be looking at a short term solution to a longer term problem.....
there are 3 or 4 nurses that frequent this site. I hope some will stop by in the next few days and offer their perspective.