Oral Presentation 50th International Society for the Study of the Lumbar Spine Annual Meeting 2024

DIFFERENT LOAD INDUCED BEHAVIOR IN INTERVERTEBRAL DISCS BETWEEN LOW BACK PAIN PATIENTS AND CONTROLS DEMONSTRATED IN A LARGE SCALE T2 MAP STUDY     (#MP-11b)

Leif LT Torén 1 2 , Helena HB Brisby 2 3 , Christian CW Waldenberg 2 4 , Kerstin KL Lagerstrand 2 4 , Hanna HH Hebelka 1 2
  1. Department of Radiology , Sahlgrenska University Hospital, Gothenburg , Sweden
  2. Sahlgrenska University Hospital, Gotheburg, Sweden
  3. Department of Orthopedics, Sahlgrenska University Hospital, Gothenburg , Sweden
  4. Deptartment of Medical Physics and Techniques , Sahlgrenska University Hospital, Gothenburg, Sweden

Introduction: Non-specific low back pain (LBP) is closely linked to degeneration of intervertebral discs (IVDs) [1, 2]. Improved imaging diagnostics for non-specific low back pain (LBP) is highly needed [3]. Small-scale quantitative MRI studies have indicated different global and regional effects of axial load on IVDs between LBP-patients and controls and between different IVD phenotypes, even when adjusted for disc-degeneration [4-7]. Prospective, large-scale quantitative studies comparing load-induced IVD behavior in patients and controls are, however, needed to confirm these findings and to gain an improved understanding of specific characteristics distinguishing IVDs in LBP patients compared to controls.

The aim of this study was to investigate the load-induced effect on lumbar IVDs in LBP patients in comparison to asymptomatic controls using T2-mapping in a large-scale prospective study.

Methods: 178 non-specific LBP patients (mean age 44 years; 20-60, 110 males, n=855 IVDs) and 74 controls (mean age 40 years; 20-60, 40 males, n=366 IVDs) were imaged with 3T MRI in the supine position with and without loading, the former simulating compressive forces in upright position [8]. Disc-delineation was made on T2 map raw images with the shortest echo-time enabling high morphological contrast. The IVDs were divided into five regions of interest (ROI1-5) in the anteroposterior direction. Global and regional (ROI3-5) mean T2 values (ms) were obtained by transforming delineated masks to calculated T2 maps. Pooled (L1/2-L5/S1) mean T2 values and level-specific mean T2 values were obtained. The effect of axial load was compared between patients and controls with Fold-change ratio, and all were adjusted for Pfirrmann grade.

Results: Axial load induced an increase of global and regional (ROI3-4) mean T2 values in both patients and controls, figure 1. The increase was 2% smaller (fold change 0.98, p=0.028) in patients compared to controls for global pooled values. The increase was 2% smaller in ROI3-4 (fold change 0.98, 0.013<p>0.026) for pooled values. Stratified for lumbar level, the increase was 4% smaller (fold change 0.96, p=0.053) in ROI3 on level L3/L4 and 3% smaller (fold change 0,97, p=0.017) in ROI4 on level L4/L5 for patients compared to controls, table 1.  

Discussion: This large-scale study demonstrates small but significant differences in load-induced behavior between patients and controls in central and dorsal parts of the lumbar IVDs. Deviant load-induced quantitative behavior of the IVDs between patients and controls on group level suggest compromised biomechanical integrity in patient IVDs, not solely attributed do degeneration. Studies exploring the correlation between these load-induced IVD differences and pain in individual patients/IVDs are needed to evaluate possible association with pain, but the present findings may be an important step in the continuous search to find IVD phenotypes specific for pain.

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  1. 1. DePalma, M.J., et al., Are outer annular fissures stimulated during diskography the source of diskogenic low-back pain? An analysis of analgesic diskography data. Pain Med, 2009. 10(3): p. 488-94.
  2. 2. Peng, B.G., Pathophysiology, diagnosis, and treatment of discogenic low back pain. World J Orthop, 2013. 4(2): p. 42-52.
  3. 3. Maher, C., M. Underwood, and R. Buchbinder, Non-specific low back pain. Lancet, 2017. 389(10070): p. 736-747.
  4. 4. Hebelka, H., et al., Axial loading during MRI reveals deviant characteristics within posterior IVD regions between low back pain patients and controls. Eur Spine J, 2018. 27(11): p. 2840-2846.
  5. 5. Toren, L., et al., MRI During Spinal Loading Reveals Intervertebral Disc Behavior Corresponding to Discogram Findings of Annular Fissures and Pain Provocation. Spine (Phila Pa 1976), 2020. 45(22): p. E1500-E1506.
  6. 6. Waldenberg, C., et al., Associations between Vertebral Localized Contrast Changes and Adjacent Annular Fissures in Patients with Low Back Pain: A Radiomics Approach. J Clin Med, 2023. 12(15).
  7. 7. Eriksson, S., et al., Texture Analysis of Magnetic Resonance Images Enables Phenotyping of Potentially Painful Annular Fissures. Spine (Phila Pa 1976), 2021.
  8. 8. Charoensuk, J., et al., Axial loading during supine MRI for improved assessment of lumbar spine: comparison with standing MRI. Acta Radiol, 2023. 64(1): p. 217-227.