What concerns should I have about spinal fusion surgery? I'm very apprehensive about my upcoming spinal fusion surgery. What should I expect from this procedure and the recovery afterward?

This depends on. Several variables: your age, your health, your weight status & nutritional status, how in shape you are, smoking history, reason for surgery, type of surgery with number of levels involved as well as approach, the experience of your surgeon, to name a few. If a smoker, 3-8x failure rate of non smoker & overweight higher risk of complications especially if diabetic. Need to discuss with surgeon!
Spinal . Spinal fusions can be very large surgeries if multiple levels are being fused. The more levels fused, the larger the incision and the larger area that is operated on --this will roughly correspond to more pain and longer recovery. Pain is readily controlled however. Everyone has pain after surgery. Pain medication is intended to make it tolerable and relatively comfortable, not to take it away completely. You will be able to lie on your back to sleep. You will be able to get up and out of bed as early as the morning after surgery, possibly with a brace on depending on how many levels are fused, which levels are fused, and other factors. It will be about a year or so before you feel "back to normal" again. On that note, it helps to keep expectations in check. If you are having a fusion for disk degeneration in your back, its typical that many levels are involved, but that the fused levels are those that are involved the most. What this means is that expecting to ultimately have no back pain at all after surgery is probably unrealistic. Beyond that, many people without any specific structural problem in their back, or one that could be improved with surgery, will complain of some level of back pain for unclear reasons.