Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Nov;25(11):3644-3649.
doi: 10.1007/s00586-016-4649-3. Epub 2016 Jun 20.

Global tilt: a single parameter incorporating spinal and pelvic sagittal parameters and least affected by patient positioning

I Obeid  1 , L Boissière  2 , C Yilgor  3 , D Larrieu  1 , F Pellisé  4 , A Alanay  3 , E Acaroglu  5 , F J Perez-Grueso  6 , F Kleinstück  7 , J M Vital  1 , A Bourghli  8 ; European Spine Study Group, ESSG
Affiliations

Global tilt: a single parameter incorporating spinal and pelvic sagittal parameters and least affected by patient positioning

I Obeid et al. Eur Spine J. 2016 Nov.

Abstract

Purpose: Regarding the close interaction between the spinal alignment and the pelvis orientation, no parameter is routinely used to describe and to evaluate the global spinopelvic balance, taking into account simultaneously the spinal part and the pelvic part of the global alignment. We described the global tilt (GT) that could analyze malalignment considering the spine and the pelvis simultaneously. From a geometrical point of view, the global tilt is the sum of the pelvic tilt (PT) and the C7 vertical tilt (angular value of sagittal vertical axis). The aim of this study is to evaluate the global tilt with comparison to PT and sagittal vertical axis (SVA), with the hypothesis that GT would be the least sensitive to positional changes.

Methods: A cohort of 22 patients with sagittal malalignment was identified from a multicentric database of adult spinal deformities (ASD). Inclusion criteria were age >30 years, SVA > 40 mm and/or PT > 20°. All patients had full spine EOS radiographs in positions 1 and 2 (P1 and P2), in which the patient was asked to stand and put his hands on his shoulders without any effort (P1), or to make an effort to be as straight as possible (P2). PT, SVA and GT were measured in both positions and changes between P1 and P2 were calculated and compared using Student's t test with significance level at p < 0.05.

Results: No significant changes were observed for GT; SVA and PT were significantly influenced by patient positioning. SVA decreased and PT increased for all cases in P2 whereas the changes in GT were in either direction. The average increase in PT was 7.1° (±5.4) or 30.8 % (±24.9); decrease in SVA was 45.1 mm (±25.6) or 60.0 % (±44.2) while the change in GT was 4.4° (±3.3) or 12.6 % (±9.3).

Discussion: GT appears to be less affected by the patient's position compared to SVA and PT. This seems logical because GT contains both spinal alignment and pelvic compensation; it is not affected by their changes in opposing directions.

Conclusion: GT appears to be the most reliable single sagittal plane parameter in ASD. It is the least affected by patient position and incorporates both the pelvic and the spinal alignment within one measure.

Keywords: Adult spinal deformity; Global tilt; Spinal malalignment; Spinal-pelvic balance.

PubMed Disclaimer

References

    1. Spine (Phila Pa 1976). 2009 Aug 1;34(17 ):1828-33 - PubMed
    1. Eur Spine J. 2015 Jun;24(6):1212-8 - PubMed
    1. Eur Spine J. 2011 Sep;20 Suppl 5:681-5 - PubMed
    1. Spine (Phila Pa 1976). 2005 Sep 15;30(18):2024-9 - PubMed
    1. Spine (Phila Pa 1976). 2006 Dec 1;31(25):E959-67 - PubMed

LinkOut - more resources