Study Design. An assessment of the difference in the degree of facet tropis
m and disc degeneration between far lateral and posterolateral lumbar disc
herniations.
Objective. To investigate the effect of the difference in the degree of the
facet tropism and disc degeneration with respect to the development of far
lateral lumbar disc herniation and posterolateral lumbar disc herniation,
and to compare the effect between the two types of herniations.
Summary of Background Data. The effect of facet tropism on the development
of posterolateral lumbar disc herniation has been investigated previously,
but there has been no study on far lateral lumbar disc herniation.
Methods. Thirty-eight lumbar disc herniations (far lateral, n = 19; postero
lateral, n = 19) were included this study. The degree of facet tropism and
disc degeneration was measured at the herniated disc level by using magneti
c resonance imaging. The results were compared to show any differences betw
een the two types of lumbar disc herniations.
Results. There were significant differences in the degree of facet tropism
(24.74 vs. 14.26, P = 0.004) and disc degeneration (23.92 vs. 15.08, P = 0.
005) between the far lateral and posterolateral lumbar disc herniations. Th
ere was no significant correlation between the degree of facet tropism and
the degree of disc degeneration in far lateral lumbar disc herniation (r =
-0.369, P = 0.120).
Conclusion. This results suggest that the differences in the degree of face
t tropism and disc degeneration might be considered a key factor in disting
uishing the development of far lateral lumbar disc herniation from that of
posterolateral lumbar disc herniation.