Association Between Facet Joint Sagittalization and Intervertebral Disc Degeneration: A Retrospective Radiological Analysis

Background To investigate the correlation between sagittalization of lumbar facet joints and lumbar intervertebral disc degeneration (IVDD). Methods Seventy-five patients with low back pain and forty healthy volunteers (control) underwent standard MRI protocols. The basic information of all patients, including age, gender, body mass index, was collected, and the lumbar facet joint angle (LFJA) was measured on lumbar magnetic resonance imaging (MRI), and the lumbar IVDD was assessed by Pfirrmann grading. All data were analyzed statistically. Results Compared with the control group, the LFJA of L3/4, L4/5 and L5/S1 in the patient group were significantly decreased, and there was a statistical difference ( P  < 0.05). The lower the segment, the more significant the sagittalization of the facet joints ( P  < 0.05). In the patient group, there was a statistically significant difference in the LFJA between the Pfirrmann grades of lumbar IVDD, and there was a strong negative correlation (ρ=-0.736, P  < 0.05). Conclusion With the increase of the sagittal degree of LFJA, the IVDD also increases significantly, and this relationship has a strong negative correlation. It is suggested that the sagittalization of facet joints may be an important pathogenic factor of lumbar IVDD.