Analysis of facet tropism of lower lumbar spine in adolescents with lumbar disc herniation

English Keywords:Lumbar disc herniation  Adolescents  Facet joint  Asymmetric  Facet tropism

English Abstract:

  【Abstract】 Objectives: To measure the angle of the lower lumbar facet joints in adolescents with lumbar disc herniation(LDH), and to observe the facet tropism(FT). Methods: This was a retrospective cohort study of patients with LDH or abdominal disease who were admitted to our hospital from August 2012 to August 2018. A total of 52 patients was included in LDH group, including 42 males and 10 females with an average age of 17.9±1.4. There were 33 patients with L4/5 disc herniation, 18 patients with L5/S1 disc herniation, one patient with L4/5 and L5/S1 disc herniation, including 24 patients with disc herniation toward the middle, 18 toward the left side, 11 toward the right side. There were 111 patients in control group, including 87 males and 24 females with an average age of 17.8±1.7. The facet joint angles of the L3-4, L4-5 and L5-S1 segment in LDH group were measured on the CT image of the lumbar spine. A line was made to connect the midpoint of the basal spinous process through the center of the intervertebral disc as the midsagittal line. This line was parallel to the lower endplate of the upper vertebral body and served as the sagittal axis of the lumbar vertebra. Another line drawn between the anteromedial and posterolateral edges of the bilateral superior articular facets was defined as the facet line. The angle between the 2 lines was the facet joint angle. FT was defined as asymmetry of >10° between the left and right side. In control group(abdominal CT group), the facet joint angles of L3-4, L4-5 and L5-S1 were measured on the CT picture of the abdomen, and the measurement method was as follows: the planes of the abdominal CT through the intervertebral disc and parallel to the lower endplate of the upper vertebral body were selected. And the remaining measurement methods and indicators were the same as those of LDH group. Results: There was no significant difference in the average fact angle of each segment between LDH group and control group(P>0.05). In LDH group, 19 patients had FT in L3/4 segment, 27 patients had FT in L4/5 segment and 24 patients had FT in L5/S1 segment. In control group, there were 19 patients, 28 patients and 18 patients with FT in corresponding segment. The probability of occurrence of FT in each segment of LDH group was significantly higher than that in control group (P<0.05). About 34 patients with L4/5 disc herniation in LDH group, FT appeared in 15 patients. Among the 19 patients with L5/S1 disc herniation, FT appeared in 13 patients. There was a significant difference(P<0.05) when FT appeared in the corresponding segment compared with that in control group(P<0.05). Conclusions: FT is common in the lower lumbar spine of adolescents with LDH, which is correlated with LDH in adolescents.