Cervical degenerative changes in idiopathic scoliosis patients who underwent long fusion to the sacrum as adults: incidence, severity, and evolution

BACKGROUND: To date, there have been no published studies of the degenerative changes in the cervical spine in adult idiopathic scoliosis patients with thoracic and lumbar curves severe enough to require major reconstructive surgery. MATERIALS AND METHODS: The primary study group was 48 adult patients who had previously undergone a fusion from T10 or higher to the sacrum as an adult for idiopathic scoliosis. These were compared to 38 adults with unfused idiopathic scoliosis of 30°–50° and to 42 symptomatic adults presenting with cervical pain. Cervical degeneration was assessed using a new cervical degenerative index (CDI). RESULTS: The amount of degenerative change seen in the cervical spine in the long-fusion group was significantly higher at baseline (just prior to the fusion) than the two control populations and became much higher at a mean follow-up of 8.5 years. CONCLUSIONS: This unique subgroup of patients, those having fusion from the thoracic spine to the sacrum as adults for adolescent idiopathic scoliosis, had a high incidence and severity of degenerative changes in their cervical spine. Due to the presence of advanced cervical degenerative changes prior to the fusion, it is not possible to blame the fusion as the main cause for these findings. These changes are either related to the thoracic and lumbar deformities or are more likely due to this subgroup having a higher natural propensity for degenerative changes.