The Effect of Global Spinal Alignment on Cervical Degeneration in Patients with Degenerative Lumbar Scoliosis

Abstract

To elucidate the effect of global spinal alignment on the cervical degeneration in Patients with Degenerative Lumbar Scoliosis (DLS). A total of 117 patients with DLS and 42 controls were analysed. DLS patients (study group) were categorized according to the SRS-Schwab classification. Patients with lumbar spinal stenosis were reviewed as a control group. Spinopelvic parameters were measured in cervical and full-length spine radiographs. Cervical degeneration was assessed using the Cervical Degeneration Index (CDI) scoring system. There were significant differences in C2-7 sagittal vertical axis, T1 Slope, thoracic kyphosis, Lumbar Lordosis (LL), and pelvic tilt between DLS and control groups. Although the DLS and control groups did not differ significantly with regard to CDI scores, a striking difference was noted when sagittal spinopelvic modifiers were considered individually. Patients with a Pelvic Incidence minus Lumbar Lordosis (PI-LL) modifier grade of ++ had significantly higher CDI scores than those with 0, and patients with a PI-LL or Sagittal Vertical Axis (SVA) modifier grade of ++ had significantly higher CDI scores than control group. Disk narrowing scores were highest in patients with a PI-LL modifier grades of ++ followed by those with +. Additionally, CDI scores were more associated with LL rather than cervical lordosis. Patients with DLS may be at greater risk of cervical spine degeneration, especially those with a PI-LL or SVA modifier grade of ++. Surgical strategy for DLS patients should be more carefully selected considering the restoration of LL.