Influence of facet joint tropism on the formation of intervertebral disc herniation in the lumbosacral spine

Objective. To evaluate the influence of facet joint tropism on the formation of intervertebral disc hernias in the lumbosacral spine, and to determine the relationship between facet joint asymmetry and the type of hernia of the lumbar intervertebral discs. Material and Methods. Sixty-four patients aged 23–47 years with herniated lumbar intervertebral discs at one level (L3–L4, L4–L5 or L5–S1) were examined. Calculation of facet angles was performed on MRI axial slices. Tropism was verified when the difference between the angles of the right and left joints exceeded 10°. Results. When calculating the facet joint angles, tropism was detected in 22 (34.3 %) cases. One-factor analysis of the effect of facet joint tropism on the intervertebral disc hernia formation at all three levels revealed its significant influence (p = 0.0017; OR 7.416; 95 % CI 3.11–22.64). Analysis of the effect of facet joint tropism on the formation of intervertebral disc hernias at each level has shown that statistically significant effect is exerted only on L5–S1 intervertebral discs (p = 0.0224; OR 13.537; 95 % CI 2.419–98.475). Conclusion. Facet joint tropism significantly influences the formation of intervertebral disc hernias at all three levels of the lumbosacral spine as a whole but does not affect the type of lumbar intervertebral disc hernia