A Study of Lumbar Disc Herniation and Facet Joint Asymmetry

Abstract

Purpose: To investigate the association of facet joint asymmetry with lumbar disc herniation at the lower lumbar spine. Methods: A total of 90 patients (ages 18–40 years) with single-level disc herniation (L3–L4, L4–L5, or L5–S1) were included in the study. Facet asymmetry was defined as a difference of 10° in facet joint angles between right and left sides. Normal discs in the same segment of other individuals were used as a control. Patients had facet asymmetry measured for L3 to S1 through 3.0T magnetic resonance imaging, and information was collected, including age, sex, degenerative degree of lumbar facet joints, and the presence or absence of lumbar disc herniation and type. Results: At the L3 to L4 level, 2 cases had facet asymmetry in 8 patients with lumbar disc herniation, compared with 17 cases of facet asymmetry in 82 patients without disc herniation (P = 0.7776, r = 0.030). At the L4 to L5 level, there were 21 cases of facet asymmetry in 45 patients with lumbar disc herniation, compared with 5 cases of asymmetry in 45 patients without disc herniation (P = 0.00019, r = 0.392). At the L5 to S1 level, there were 25 cases of facet asymmetry in 37 patients with lumbar disc herniation, compared with 11 cases of facet asymmetry in 53 patients without disc herniation (P = 0.0000, r = 0.492). There were 23 cases of facet asymmetry in 28 disc herniations of side type compared with 2 cases of facet asymmetry in 9 herniations of center type (P = 0.0008, r = 0.364). There was no significant difference in the relationship between age, facet joint degeneration, and lumbar facet joint asymmetry (P > 0.05). Conclusion: Facet asymmetry is significantly associated with lumbar disc herniation at the L4 to L5 and the L5 to S1 levels, whereas there is an obvious association with the side type of lumbar disc herniation at the L5 to S1 level.