Age-related differences in the response of the L5-S1 intervertebral disc to spinal traction

Musculoskelet Sci Pract. 2017 Oct;31:1-8. doi: 10.1016/j.msksp.2017.06.004. Epub 2017 Jun 9.

Abstract

Background: Lumbar traction is a common treatment for low back pain; however its mechanisms of action are poorly understood. It has been hypothesized that a key effect of lumbar traction is its capacity to influence fluid movement within the intervertebral disc (IVD).

Objectives: To determine differences in the apparent diffusion coefficient (ADC) obtained with lumbar diffusion-weighted imaging (DWI) of the L5-S1 IVD before, and during, the application of lumbar traction.

Design: Case series, repeated measures.

Methods: A static traction load of ∼50% of body-weight was applied to the low back using a novel "MRI-safe" apparatus. DWI of the lumbar spine was performed prior to, and during the application of the traction load.

Results: Participants were currently asymptomatic and included a young adult group (n = 18) and a middle-aged group (n = 15). The young adult group had a non-significant 2.2% increase in ADC (mean change = 0.03 × 10-3 mm2/s, SD = 0.24, 95% CI = -0.09, 0.15). The ADC for the middle-aged group significantly increased by 20% (mean change of 0.18 × 10-3 mm2/s, SD = 0.19; 95% CI = 0.07, 0.28; p = 0.003; effect size = 0.95). There was an inverse relationship between the ADC obtained before traction and the percent increase in ADC that was measured during traction.

Conclusion: Static traction was associated with an increase in diffusion of water within the L5-S1 IVDs of middle-age individuals, but not in young adults, suggesting age-related differences in the diffusion response. Further study is needed to assess the relationship between these findings and the symptoms of back pain.

Level of evidence: 4.

Keywords: Back pain; Disc degeneration; Disc health; Fluid flow; Regenerative medicine.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Diffusion Magnetic Resonance Imaging / methods*
  • Female
  • Humans
  • Intervertebral Disc Displacement / diagnostic imaging
  • Intervertebral Disc Displacement / physiopathology*
  • Intervertebral Disc Displacement / therapy*
  • Low Back Pain / therapy*
  • Lumbosacral Region / physiopathology*
  • Male
  • Middle Aged
  • Traction / methods*
  • Young Adult