Prospective clinical study on natural history of discogenic low back pain at 4 years of follow-up.
To accurately assess the effect of any therapy for treating discogenic low back pain, the natural history of such pain should be known beforehand. However, until now, no pathological characteristic could be used to predict the disease course of low back pain. To better instruct the clinical treatment of discogenic low back pain, a prospective clinical study was performed to observe the natural history of the disease. A prospective clinical study during a 4-year follow-up period. The study was performed at a spinal center in China. A total of 279 patients with chronic low back pain were included from June 2006 through October 2007. Using discography, 156 patients (56%) were diagnosed to have discogenic back pain. A 101-point numerical rating scale (NRS) was used to assess the back pain symptoms and the Oswestry Disability Index (ODI) was used to assess lumbar function. Of the 156 patients, 131 (84%) completed the study at 4-year follow-up. At the end of follow-up, 17 patients (13.0%) had their low back pain symptoms alleviated and lumbar function improved; 10 patients (7.6%) were slightly improved; 16 patients (12.2%) had their symptoms aggravated; and 88 patients (67.2%) experienced the same pain and disability as before. Although the average NRS and ODI scores obtained during the 4-year follow-up study gradually decreased, statistical significances were found in such changes (P < 0.05,and P < 0.05, respectively); however, the improvement rates of both pain (7.6%) and disability (5.2%) were very low. The shortcoming of this study is its relatively small sample size. The present study indicated that the natural history of discogenic low back pain was chronic but persistent, and that the pain and disability in most patients did not improve over time.