The Clinical Course of Modic Changes and Significance Following Microendoscopic Discectomy

Abstract：Objective To evaluate the clinical course of Modic changes and significance following microendoscopic dis-cectomy. Methods A retrospective analysis was made in 85 patients with single-level lumbar disc herniation who underwent microendoscopic discectomy and had complete follow-up data from July 2004 to January 2007. According to Modic classification standard,85 patients were divided into three groups:Modic type 0(n = 33 cases),Modic type Ⅰ(n = 25 cases),Modic type Ⅱ(n = 27 cases). The operative effect was assessed according to Visual Analogue Score(VAS)and Oswestry Disability Index (ODI). Then,the clinical course of Modic changes and impact to operative effect were observed. Results All patients were followed up for 4. 1 years on average. At last follow-up,the prevalence of Modic changes increased from 61. 1% to 84. 7% ,and 60 patients had Modic Type Ⅱ at the operated level. Of the 33 patients without Modic changes,7 converted to Type Ⅰ,15 to Type Ⅱ,11 remained Type 0. Of the 25 Type Ⅰ changes,18 converted to Type Ⅱ,2 reversed to Modic Type 0,5 remained Type Ⅰ. None of the 27 Type Ⅱ changes converted to the other type. There were no significant differences in VAS(low back pain and leg pain)and ODI score within three groups before operation(P > 0. 05). At last follow-up,VAS(low back pain and leg pain)and ODI score were significantly improved(P < 0. 05). At last follow-up,there were significant differences in low back pain VAS and ODI score improvement rate within three groups(P < 0. 05),but the leg pain VAS score were not signifi-cant differences within the three(P > 0. 05). There were significant differences in low back pain VAS and ODI score improve-ment rate in any two groups within the three(P < 0 05),operative effect comparison as follows:Modic type Ⅰ > Modic type 0> Modic type Ⅱ. Conclusion Microendoscopic discectomy is an effective treatment for lumbar disc herniation. Modic chan-ges can convert each other following discectomy,and appear to affect the prognosis of low back pain.