I find that elevated deads actually put more stress on my lower back. if you think about it, the lower portion of a dead is initiated by the quads, hips and groin. it isn't until the weight reaches knee level that the lower really comes into play.
lately, i've been training my sticking point which is just below the knee. my lower back has really started to become irritated. the reason is that in a normal dead, my speed off the floor helps to keep the stress on my lower back to a minimum. starting from a dead stop at my sticking point places all that stress directly on my lower back. the movement is still very effective but i need to lay off of them to give my lower back a break. if you already have lower back issues, elevated pulls may aggrevate the problem.
i would look into doing specific back work to rehab the area and then start back with full ROM deads keeping it light. once you are fully healed, then look into elevated deads.