Impact of cervical and global spine sagittal alignment on cervical curvature changes after posterior cervical laminoplasty

J Orthop Surg Res. 2022 Dec 2;17(1):521. doi: 10.1186/s13018-022-03421-w.


Objective: To analyze the correlation between the changes in cervical curvature and the sagittal parameters of spino-pelvic and clinical efficacy after posterior laminoplasty (LP).

Methods: The patients with cervical spondylosis treated with LP from June 2018 to December 2020 were reviewed. The preoperative and follow-up spine full-length films were measured. The measured data included C2-C7 Cobb angle, C2-7 sagittal vertical axis (SVA), T1 slope (T1S), pelvic incidence, sacral slope (SS), pelvic tilt (PT), lumbar lordosis (LL), thoracic kyphosis (TK), and C7-SVA. Japanese Orthopaedic Association (JOA) score and neck disability index (NDI) score were recorded before surgery and follow-up.

Results: There were 56 patients in this study. There were no significant differences in spino-pelvic sagittal parameters before and after surgery; however, the JOA score significantly improved. The changes in postoperative cervical lordosis correlated with SS, PT, LL, T1S, and C7-SVA (P < 0.05). Regression analysis showed that T1S and C7-SVA were associated with reducing cervical lordosis (P = 0.021 and P = 0.001, respectively). Patients with larger T1S combined with larger C7-SVA had more cervical lordosis loss, poor JOA improvement, and high postoperative NDI scores (P < 0.001, P = 0.018, and P < 0.001, respectively).

Conclusion: Patients should be examined with full-length spine film before surgery to evaluate the cervical and spino-pelvic sagittal balance. T1S and C7-SVA correlated with changes in cervical sagittal alignment after LP.

Level of evidence: III.

Keywords: Cervical sagittal alignment; Laminoplasty; Spino-pelvic sagittal balance.

MeSH terms

  • Animals
  • Humans
  • Laminoplasty*
  • Lordosis* / diagnostic imaging
  • Lordosis* / surgery
  • Neck
  • Pelvis
  • Sacrum