While I have no medical opinion to back this up, I place a significant portion of blame on the mechanics of being released. I was upright in a wheelchair, then forced to stand up to get into my wife's car, then had to drive home upright, then had to stand up again to get into a wheelchair to get into my house. I believe the fact that my back was forced to take weight immediately following surgery did a lot of damage. If I could do it over again I would have insisted on remaining prone for at least the first 24 hours.