Postoperative cervical sagittal imbalance negatively affects outcomes after surgery for cervical spondylotic myelopathy

Spine (Phila Pa 1976). 2014 Dec 1;39(25):2070-7. doi: 10.1097/BRS.0000000000000641.


Study design: Prospective observational cohort study.

Objective: To determine if postoperative cervical sagittal balance is an independent predictor of health-related quality of life outcome after surgery for cervical spondylotic myelopathy.

Summary of background data: Both ventral and dorsal fusion procedures for CSM are effective at reducing the symptoms of myelopathy. The importance of cervical sagittal balance in predicting overall health-related quality of life outcome after ventral versus dorsal surgery for CSM has not been previously explored.

Methods: A prospective, nonrandomized cohort of 49 patients undergoing dorsal and ventral fusion surgery for CSM was examined. Preoperative and postoperative C2-C7 sagittal vertical axis was measured on standing lateral cervical spine radiographs. Outcome was assessed with 2 disease-specific measures-the modified Japanese Orthopedic Association scale and the Oswestry Neck Disability Index and 2 generalized outcome measures-the Short-Form 36 physical component summary (SF-36 PCS) and Euro-QOL-5D. Assessments were performed preoperatively, and at 3 months, 6 months, and 1 year postoperatively. Statistical analyses were performed using SAS version 9.3 (SAS Institute).

Results: Most patients experienced improvement in all outcome measures regardless of approach. Both preoperative and postoperative C2-C7 sagittal vertical axis measurements were independent predictors of clinically significant improvement in SF-36 PCS scores (P = 0.03 and P = 0.02). The majority of patients with C2-C7 sagittal vertical axis values greater than 40 mm did not improve from an overall health-related quality of life perspective (SF-36 PCS) despite improvement in myelopathy. The postoperative sagittal balance value was inversely correlated with a clinically significant improvement of SF-36 PCS scores in patients undergoing dorsal surgery but not ventral surgery (P = 0.03 vs. P = 0.93).

Conclusion: Preoperative and postoperative sagittal balance measurements independently predict clinical outcomes after surgery for CSM.

Level of evidence: 2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cervical Vertebrae / physiopathology
  • Cervical Vertebrae / surgery*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Postoperative Complications / etiology
  • Postoperative Complications / physiopathology
  • Postural Balance
  • Prospective Studies
  • Quality of Life
  • Sensation Disorders / etiology*
  • Sensation Disorders / physiopathology
  • Spinal Fusion / adverse effects
  • Spondylosis / surgery*
  • Treatment Outcome