The lumbar lordosis index: a new ratio to detect spinal malalignment with a therapeutic impact for sagittal balance correction decisions in adult scoliosis surgery

Eur Spine J. 2013 Jun;22(6):1339-45. doi: 10.1007/s00586-013-2711-y. Epub 2013 Feb 15.


Purpose: Sagittal malalignment is frequently observed in adult scoliosis. C7 plumb line, lumbar lordosis and pelvic tilt are the main factors to evaluate sagittal balance and the need of a vertebral osteotomy to correct it. We described a ratio: the lumbar lordosis index (ratio lumbar lordosis/pelvic incidence) (LLI) and analyzed its relationships with spinal malalignment and vertebral osteotomies.

Methods: 53 consecutive patients with a surgical adult scoliosis had preoperative and postoperative full spine EOS radiographies to measure spino-pelvic parameters and LLI. The lack of lordosis was calculated after prediction of theoretical lumbar lordosis. Correlation analysis between the different parameters was performed.

Results: All parameters were correlated with spinal malalignment but LLI is the most correlated parameter (r = -0.978). It is also the best parameter in this study to predict the need of a spinal osteotomy (r = 1 if LLI <0.5).

Conclusion: LLI is a statistically validated parameter for sagittal malalignment analysis. It can be used as a mathematical tool to detect spinal malalignment in adult scoliosis and guides the surgeon decision of realizing a vertebral osteotomy for adult scoliosis sagittal correction. It can be used as well for the interpretation of clinical series in adult scoliosis.

MeSH terms

  • Adult
  • Aged
  • Female
  • Humans
  • Lordosis / diagnosis*
  • Lordosis / diagnostic imaging
  • Lordosis / surgery
  • Male
  • Middle Aged
  • Radiography
  • Scoliosis / diagnostic imaging
  • Scoliosis / surgery*
  • Spinal Fusion
  • Spine / diagnostic imaging*
  • Spine / surgery*
  • Treatment Outcome