[Distribution characteristics of Modic changes of lumbar endplate and its relationship with low back pain].

OBJECTIVE: To investigate the incidence of Modic changes of lumbar endplate and its clinical significances. METHODS: The imaging data of 562 patients (2,810 lumbar intervertebral discs) with lumbar degenerative disease undergoing posterior operation from June 2006 to June 2009 were retrospectively reviewed. There were 297 males and 265 females aged 26-77 years old (average 49 years old). The course of disease was 2 months to 40 years (median 10.4 years). Imaging examinations excluded the tuberculosis, cancer, infection, trauma, etc. The association of Modic changes with low back pain (LBP) and patients' weight was analyzed according to the incidence and types of Modic changes as well as the distribution of gender, age and disc level through imaging data of MRI. RESULTS: Modic changes were observed in 106 patients (18.9%) of 113 intervertebral discs, including 40 (13.5%) males and 66 (24.9%) females. The difference between male proportion and female proportion had a significant difference (P < 0.05). Modic changes was distributed from age 26 to 77 years old (average 49 years old). Among all the patients, 33 cases (5.9%) were type I, 66 cases (11.7%) were type II, and 7 cases (1.2%) were type III. According to the segment, the lesions involved L5, S1 disc for 58 discs (51.3%), L4, 5 for 35 (31.0%), L3, 4 for 11 (9.7%), L2, 3 for 6 (5.3%), and L1, 2 for 3 (2.7%). The incidence of Modic change was 15.5% (41/264) in the normal body weight group, 16.3% (34/208) in the over-weight group, and 34.4% (31/90) in the obesity group. There was a significant association between obesity and the Modic change (P < 0.05). Preoperatively, there were 59 patients (55.7%) with LBP in the Modic group, including 27 cases of type I Modic change, 27 cases of type II Modic change, and 5 cases of type III Modic change. Postoperatively, the LBP of 40 patients (67.8%) were relieved, including 24 cases of type I Modic change, 14 cases of type II Modic change, and 2 cases of type III Modic change. In non-Modic change group, there were 126 patients (27.6%) with LBP preoperatively, and 96 patients (76.2%) eased the symptoms postoperatively. There was significant difference between two groups on incidence rate (P < 0.05), but no significant difference on the remission rate of LBP (P > 0.05). CONCLUSION: The most common Modic change is type II and the most frequently involved level is the L5, S1. Modic changes are more common in female than in male and mainly happen to the obesity group. The incidence of LBP is higher in the patients with Modic change.