Correlations Between The Feature Of Sagittal Spino-Pelvic Alignment And Facet Joint Degeneration

Background:Loss of normal spinopelvic alignment may accelerate degeneration of motion segments.The motion segment is composed of three articulations between adjacent vertebrae: two facet joints and one disc.A series of studies investigated the correlation of sagittal alignment with lumbar disc degenerative diseases [4–6].Most researchers have treated the facet joint as a part of the spine,analysing the whole spine by dividing it into conditions with or without degeneration.Relatively few studies have examined the features of spinopelvic alignment in patients with lumbar facet joint degeneration.However,the correlation between sagittal alignment and lumbar facet joint degeneration is still unclear.Therefore,we performed this study to clarify the relationship between the degree of lumbar facet joint degeneration and spinopelvic sagittal parameters,providing available information for the early detection and treatment of lumbar facet joint osteoarthritis.Methods:Imaging data of 140 individuals were retrospectively analysed.Lumbar lordosis,pelvic tilt(PT),pelvic incidence(PI),sacral slope,and height of the lumbar intervertebral disc were measured on lumbar X-ray plates.Grades of facet joint degeneration were evaluated from the L2 to S1 on CT scans.Spearman’s rank correlation coefficient and Student’s t-test were used for statistical analyses and a Pvalue <0.05 was considered statistically significant.Results:PI was positively associated with degeneration of the facet joint at lower lumbar levels(p < 0.001 r = 0.50 at L5/S1 and P = 0.002 r = 0.25 at L4/5).PI was significantly higher in the severe degeneration group compared to the mild degeneration group:52.6vs 47.6°,P = 0.042 at L3/4;53.0° vs 45.9°,P<0.001 at L4/5;53.9° vs 43.5°,P<0.001 at L5/S1.A significant increase of PT was found in the severe degeneration group compared with the mild degeneration group: 21.4°vs 15.1°,P = 0.006 at L3/4;21.0° vs 13.5°,P<0.001 at L4/5;20.8° vs 12.1°,P<0.001 at L5/S1.Conclusion:Our results indicate that a high PI is a predisposing factor for facet joint degeneration at the lower lumbar spine,and that severe facet joint degeneration may accompany with greater PT at lumbar spine.