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

Extra-segmental Influence of Lower Lumbar Disc Degeneration on Development of Osteoporotic Vertebral Fractures at Thoraco-Lumbar Junction. (#185)

Parker R Martin 1 , Francisco Rivas Rodriquez 2 , Aseem Sharma 2
  1. St. Luke's University, Easton, USA
  2. University of Michigan, Saint Louis, ANN ARBOR, MI 48109, USA, United States

Introduction. Prior studies have indicated protective effect of disc degeneration in a given vertebral segment against development of osteoporotic vertebral fracture (OVF) within that segment. However, extra-segmental effects of disc degeneration on OVF occurrence has not been studied. We aimed to study the influence of the disc degeneration in the lower lumbar spine- the most common location of disc degeneration, with the development of OVFs at the thoracolumbar junction (T12 and L1 vertebrae)- the most common location of osteoporotic vertebral fractures.

Methods. This retrospective study included 83 patients (69 females; mean ±  SD  age: 72.3 ± 14.0 years) with OVFs. Using lumbar MRI, two neuroradiologists evaluated 498 lumbar vertebral segments for presence and acuity of OVFs and graded intervertebral discs on Pfirrmann’s scale. Using Pfirrmann grade >2 as abnormal, we calculated Lower Lumbar Degeneration Burden (ranging from 0-3, indicating number of abnormal intervertebral discs in L3-S1 segments) for each patient. We also calculated Lower Lumbar Degeneration Severity Score (ranging from 3-15, indicating sum of Pfirrmann grades for intervertebral discs in L3-S1 segments) for each patient.   TL Fracture Burden at thoracolumbar junction (0, 0.5, or 1 indicating OVFs in neither, one, or both T12 and L1 vertebral segments respectively) was also calculated for each patient.  TL Fracture Burden was compared for patients across different levels of Lower Lumbar Degeneration Burden and Lower Lumbar Degenerative Severity Score using two sample t-test and Pearson coefficient correlation.  We considered p value of < 0.05 as significant. 

 Results. OVFs were seen in 33/83 (39.8%; 22.9% acute) T12 and 36/83 (39.8%, 20.5% acute) L1 vertebral segments, with overall mean ± SD OVF burden at thoracolumbar junction being 0.41 ± 0.35. Mean ± SD Lower Lumbar Degeneration Burden for the study group was 2.74 ± 0.65, with disc degeneration seen at all three IVDs in L3-S1 segments (Lower Lumbar Degeneration Burden of 3) in most (51/83, 61.5%) patients. Mean ± SD Lower Lumbar Degeneration Severity Score was 9.6 ± 2.1. Patients without any signs of disc degeneration in L3-S1 segments (Lower Lumbar Degeneration Burden = 0; n=7, 8.4%) showed a significantly higher TL Fracture Burden (mean ± SD: 0.71 ± 0.39) when compared to patients with Lower Lumbar Degeneration Burden of >0 (mean ± SD: 0.39 ± 0.33, p=0.015, Fig.1). Neither Lower Lumbar Degeneration Burden nor Lower Lumbar Degeneration Severity Score correlated with TL Fracture Burden (Correlation Coefficient: 0.125 and -0.052 respectively, p=0.28 and 0.64 respectively).  

Discussion. Presence but not the extent or severity of disc degeneration (as defined by Pfirrmann grade >2) in the lower lumbar spine has extra-segmental protective effect against development of OVFs at thoracolumbar junction. This extra-segmental protection against OVFs afforded by lower lumbar disc degeneration may be related to dissipation of axial load transmitted across the thoracolumbar junction in presence of disc degeneration.

654fda6d25cce-Fig.+1.jpg

 

654fda6d25cce-Slide1.jpeg

 

  1. Sharma A, Martin PR, Rodriguez FR (2023) Lumbar osteoporotic fractures develop in segments with less degenerated discs which then become more degenerated. Eur Spine J. https://doi.org/10.1007/s00586-023-07573-z. Epub ahead of print. PMID: 36795180.
  2. Dai L. The relationship between vertebral body deformity and disc degeneration in lumbar spine of the senile. European Spine Journal. 1998 Feb;7(1):40-4.
  3. Miyakoshi N, Itoi E, Murai H, Wakabayashi I, Ito H, Minato T. Inverse relation between osteoporosis and spondylosis in postmenopausal women as evaluated by bone mineral density and semiquantitative scoring of spinal degeneration. Spine. 2003 Mar 1;28(5):492-5.
  4. Roux C, Fechtenbaum J, Briot K, Cropet C, Liu-Léage S, Marcelli C. Inverse relationship between vertebral fractures and spine osteoarthritis in postmenopausal women with osteoporosis. Annals of the rheumatic diseases. 2008 Feb 1;67(2):224-8.