Maintenance of radiographic correction at 2 years following lumbar pedicle subtraction osteotomy is superior with upper thoracic compared with thoracolumbar junction upper instrumented vertebra

Eur Spine J. 2015 Jan;24 Suppl 1:S121-30. doi: 10.1007/s00586-014-3391-y. Epub 2014 Jun 1.

Abstract

Purpose: The goal of this study was to characterize the spino-pelvic realignment and the maintenance of that realignment by the upper-most instrumented vertebra (UIV) for adult deformity spinal (ASD) patients treated with lumbar pedicle subtraction osteotomy (PSO).

Methods: ASD patients were divided by UIV, classified as upper thoracic (UT: T1-T6) or Thoracolumbar (TL: T9-L1). Complications were recorded and radiographic parameters included thoracic kyphosis (TK, T2-T12), lumbar lordosis (LL, L1-S1), sagittal vertical axis (SVA), pelvic tilt, and the mismatch between pelvic incidence and LL. Patients were also classified by the Scoliosis Research Society (SRS)-Schwab modifier grades. Changes in radiographic parameters and SRS-Schwab grades were evaluated between the two groups. Additional analyses were performed on patients with pre-operative SVA ≥ 15 cm.

Results: 165 patients were included (UT: 81 and TL: 84); 124 women, 41 men, with average age 59.9 ± 11.1 years (range 25-81). UT had a lower percentage of patients above the radiographic thresholds for disability than TL. UT had a significantly higher percentage of patients that improved in SRS-Schwab global alignment grade than the TL group at 2 years. Within the patients with pre-operative SVA ≥ 15 cm, TL developed significantly increased SVA and had a significantly higher percentage of patients above the SVA threshold at 3 months, and 1 and 2 years than UT.

Conclusions: Patients undergoing a single-level PSO for ASD who have fixation extending to the UT region (T1-T6) are more likely to maintain sagittal spino-pelvic alignment, lower overall revision rates and revision rate for proximal junctional kyphosis than those with fixation terminating in the TL region (T9-L1).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Follow-Up Studies
  • Humans
  • Lumbar Vertebrae / diagnostic imaging*
  • Lumbar Vertebrae / surgery*
  • Male
  • Middle Aged
  • Osteotomy / methods*
  • Radiography
  • Reoperation / statistics & numerical data
  • Retrospective Studies
  • Spinal Curvatures / surgery
  • Spinal Fusion
  • Thoracic Vertebrae / diagnostic imaging*
  • Thoracic Vertebrae / surgery*