Association between lumbar segmental mobility and intervertebral disc degeneration quantified by magnetic resonance imaging T2 mapping

BACKGROUND: The relation between segmental mobility and degree of lumbar degenerative change is still unknown. This cross-sectional study aimed to elucidate the association between intervertebral disc degeneration (IVDD) and segmental mobility in chronic low back pain using magnetic resonance imaging (MRI) T2 mapping. METHODS: Subjects comprised 60 patients (29 men, 31 women; mean age, 61.8 ± 1.9 years; range, 41–79 years). T2 values of the anterior annulus fibrosus (AF), the nucleus pulposus (NP) and the posterior AF were evaluated with MRI T2 mapping. Facet joint degeneration was divided into 4 grades using MRI. We analyzed the correlation between segmental mobility and T2 values of anterior AF, NP and posterior AF using multiple linear regression analysis adjusted for age and facet joint degeneration. RESULTS: The standardized partial regression coefficient of the anterior AF, NP and posterior AF T2 values were 0.125 (p=0.72), 0.499 (p<0.01) and –0.026 (p=0.11), respectively, for the L1-2 level; 0.102 (p=0.27), 0.395 (p<0.01) and –0.094 (p=0.20), respectively, for the L2-3 level; 0.108 (p=0.38), 0.415 (p<0.01) and –0.050 (p=0.51), respectively, for the L3-4 level; 0.124 (p=0.09), 0.396 (p<0.01) and 0.025 (p=0.73), respectively, for the L4-5 level; and 0.011 (p=0.89), 0.443 (p<0.01) and 0.030 (p=0.72), respectively, for the L5-S level. There was a significantly positive correlation between segmental mobility and the T2 values of NP at L1–L2, L2–L3, L3–L4, L4–L5, and L5–S1. No significant correlations arose between segmental mobility and the T2 values of the anterior AF and the posterior AF at L1–L2, L2–L3, L3–L4, L4–L5, and L5–S1. CONCLUSION: Characterization of the relationship between NP degeneration and lumbar segmental mobility may enhance our ability to evaluate the changes seen in kinematics of functional spinal unit.