Spinal Fusion Well Tolerated in Idiopathic Scoliosis
Most adolescents show new disc pathology but fewer degenerative changes at junctional level
THURSDAY, April 14 (HealthDay News) -- Despite accelerated L5-S1 disc degeneration, patients with adolescent idiopathic scoliosis (AIS) maintain good function and balance more than 10 years after spinal fusion, according to a study published online Feb. 1 in Spine.
Daniel W. Green, M.D., from the Hospital for Special Surgery in New York City, and colleagues described the long-term clinical and imaging results of the adult uninstrumented lumbar spine after posterior spinal thoracic fusion for AIS. A total of 20 patients with 90 discs below fusions were followed up for an average of 11.8 years, during which time they underwent examination, X-rays, and magnetic resonance imaging (MRI), and completed functional and pain outcome questionnaires (Oswestry and Scoliosis Research Society 22 [SRS]). MRIs were evaluated to see evidence of lumbar disc degeneration below the fusion.
The investigators found that the distal fixation was performed at L1 on average and the major curve was corrected from 55 degrees preoperatively to 25 degrees postoperatively. New disc pathology was seen in 85 percent of the patients on follow-up MRI. Most pathology was seen at the L5-S1 disc, where average degenerative scores increased from 1.2 preoperatively to 2.3 postoperatively, with only one patient demonstrating degenerative disc disease at the junctional level. Degenerative changes at uninstrumented levels deteriorated from an average Pfirrmann grade of 1.1 preoperatively to 1.8 at follow-up. Three patients with severe disc disease had mild SRS and Oswestry changes and took NSAIDs but not narcotics for pain.
"Despite demonstrating an accelerated rate of L5-S1 disc degeneration, our study group of patients with moderate AIS has good functional scores and maintenance of balance and correction over 10 years post-fusion," the authors write.