My quick story to share about my fusion, I know most of you may not have scoliosis but I had a fusion also.
I had harrington rod/fusion surgery for scoliosis almost 23 years ago. In the last 10-15 + years, I have had terrible complications from the surgery, neurosurgeon calls it flatback syndrome. My 2 rods start at T3 and end at L2, they took bone off my left hip at the time of surgery to fuse the spine.
I have been in and out of doctor's offices, counselors, physical therapy, seen many massage therapists, chiropractors, multiple prescription use, and also have used many modalities of alternative medicine because I suffer from chronic pain all the time, fibromyalgia symptoms, myofascial pain (tons of knots in the muscles...everywhere), pinching and burning of nerves and especially around the rods/fusion and my legs, extreme dizziness/vertigo, migraines that last for weeks, TMJ disorder, bulged disks, abnormal forward curvature (at least 30%) of the cervical spine, degenerating disks, pre osteoarthritis, arthritis, bursitis, sciatica, numbness , burning, and tingling of extremities, muscle fatigue and weakness/atrophy, edema, shortness of breath, thyroid issues, gall bladder issues, hypoglycemia, poor concentration, memory problems, moodiness and depression, sleep issues... I think that just about covers it all :( I never had any pain or any issues before my surgery, even though I was only eleven. Many other scoliosis friends that have had fusions are suffering with the same things as well because of the long term outcomes.