Association of Modic change types and their short tau inversion recovery signals with clinical characteristics- a cross sectional study of chronic low back pain patients in the AIM-study
Authors: Bråten Lars Christian Haugli , Schistad Elina Iordanova , Espeland Ansgar , Kristoffersen Per Martin , Haugen Anne Julsrud , Marchand Gunn Hege , Vetti Nils , Pripp Are Hugo , Kadar Thomas Istvan , Skouen Jan Sture , Grotle Margreth , Grøvle Lars , Zwart John-Anker , Brox Jens Ivar , Storheim Kjersti ,   The AIM-study group, Anke Audny , Wilhelmsen Maja , Fors Terese , Kjos Guro , Østhus Ida Beate , Lurud Britt Elin , Granvigen Fredrik , Andersen Hege , Nygaard Øystein Petter , Rao Vidar , Claussen Siv Krüger , Andersen Erling , Froholdt Anne , Randen Sigrun , Presberg Hilde , Wigemyr Monica , Pedersen Linda Margareth , Winsvold Bendik Slagsvold , Rolfsen Mads Peder , Helllum Christian , Gammelsrud Karianne Wiger , Vigeland Maria Dehli , Lie Benedicte Alexandra , Flåm Siri Tennebø , Vigeland Magnus Dehli , Thorsø Marianne , Huneide Knut Morten , Sørensen Veronica , Lutro Olav , Holmgard Thor Einar 
Published: June 2020

Abstract
Background
Modic Changes (MCs, magnetic resonance imaging (MRI) signal changes in the vertebral bone marrow extending from the vertebral endplate) may represent a subgroup of nonspecific chronic low back pain that could benefit from a specific management. The primary aim was to compare clinical characteristics between patients with type 1 versus type 2 MCs. The secondary aim was to explore associations between clinical characteristics and MC related short tau inversion recovery (STIR) signals.

Methods
This cross-sectional study used baseline data prospectively collected between 2015 and 2017 on the 180 patients included in the AIM-study (Antibiotics In Modic changes), a randomized controlled trial in a Norwegian hospital out-patient setting of patients with chronic low back pain, a lumbar disc herniation within the last 2 years, low back pain intensity score ≥ 5 (on a 0–10 scale) and current type 1 or type 2 MCs at the previously herniated lumbar disc level. We used prespecified clinical characteristics including self-report measures, physiologic measures and functional measures from clinical history and examination. The diagnostic accuracy of various clinical characteristics to discriminate between patients with type 1 MCs (with or without additional type 2 MCs) and patents with type 2 MCs only (not type 1) were assessed by calculating the area under the receiver-operating curve. We assessed the correlations of clinical characteristics with details of MC related STIR signal increase.

Results
No clinical characteristic differed between patients with type 1 (n = 118) versus type 2 (but not type 1) (n = 62) MCs. The clinical characteristics showed no/minor differences or no/weak correlations with MC related STIR signal increase. Patients with a positive Springing test (at any lumbar level) had slightly less volume of STIR signal increase than those with a negative test (mean difference 1.3 on a 0–48 scale, 95% CI 0.3 to 2.3).

Conclusion
Clinical characteristics were similar for patients with type 1 MCs and patients with type 2 MCs, and showed no clinically relevant correlations with MC related STIR signal increase.

Trial registration
ClinicalTrials.gov NCT02323412, First registered 23 December 2014