Hi there -- Thanks for your question. First off, I should be clear that this is a question that may be best answered by your doctor, and we of course are not qualified to provide any kind of medical advice. With that said, I do think having a mattress with excellent pressure relief -- something that almost all Tempur-Pedic mattress models have in common -- should be helpful with this condition.

And of course, to ensure that your spine is properly aligned on the mattress, you are going to want to make sure that the model you choose fits your weight and sleep position. Lighter people and side sleepers will need more softness and conformance, while heavier people and stomach sleepers will need less. This is true for all sleepers, but probably even more important for people with spondylolisthesis.

So if I were to take excellent pressure relief and proper spinal alignment fit as a given, my next biggest concern in this case might be to choose the model that would afford the least amount of movement for my spine. This is a bit tricky because all Tempur models will have some amount of "travel" on account of the slow-melting sensation that memory foam provides (which is part of what makes it good for pressure relief). With the firmer models, the process of sinking into the bed will be very slow -- it can take 10 seconds or more for the bed to fully mold to your body when you change positions. With the softest models, this can be significantly faster. TBH I don't know which would be better in your case -- I imagine it would depend on the specific nature of your condition -- but I would probably factor this into my final decision one way or another.

Sorry I can't be more specific here since the answer clearly depends on more than just the spondylolisthesis condition alone, but I hope that my thought process was helpful for you nonetheless. Don't forget to check with your doctor for their recommendation as well.