Association of facet tropism and orientation with lumbar disc herniation in young patients.

Facet tropism and orientation are thought to be associated with lumbar disc herniation (LDH), but the relationship is not well established. Moreover, the effect of facet joint on LDH has not been outlined in young patients. The objective of this study was to investigate the associations of facet joint tropism and orientation with LDH in young patients (18-35 years) by computed tomography (CT). Fifty-three patients with LDH and 129 with neither LDH nor low back pain (18-35 years) were included in this study. The facet joint angles were measured for each facet joint by CT as per the method described by Noren et al. We defined facet tropism as a bilateral angle difference > 5°. Young cases with neither LDH nor low back pain were used as the control group. The results showed that LDH was significantly associated with more coronal facet joint orientation at L1-2 (p = 0.009), L2-3 (p = 0.004), and L3-4 (p = 0.004). No association was established between facet tropism and LDH. This study revealed that facet joint orientation was associated with LDH in young patients (18-35 years); they were more of coronal facing at upper levels. Also, the facet tropism was not associated with LDH.