ObjectiveTo observe the efficacy and safety of the posterior fusion dynamic system (Dynesys) on lumbar intervertebral disc. MethodsBetween April 2010 and April 2012, 30 patients diagnosed lumbar disc herniation in our department were included in the study. The Dynesys was performed on these patients. Follow-up lasted for 6 to 12 months. We used visual analogue scale (VAS) and Oswestry disability index (ODI) to evaluate the efficacy and safety of the system at the time points of the day before surgery, 1 week, 3 months and 6 months after surgery. Paired-samples t-test was used in the data analysis. ResultsThe VAS score 1 day before surgery was 7.9±0.9; 1 week after surgery, VAS was 2.1±0.8 (t=49.395, P<0.001); 3 months after surgery, VAS was 1.6±0.4 (t=88.304, P<0.001); 6 months after surgery, VAS was 1.4±0.3 (t=93.721, P<0.001). ODI 1 day before surgery was (74.0±6.0)%; 1 week after surgery, ODI was (19.6±2.5)% (t=82.006, P<0.001); 3 months after surgery, ODI was (16.3±1.2)% (t=88.344, P<0.001); 6 months after surgery, ODI was (14.5±1.8)% (t=90.113, P<0.001). All the patients were given X ray review 1 week, 3 months, and 6 months after surgery. No screw loosening or breakage was detected. ConclusionThe combination of Dynesys and decompression surgery has been proved to be effective and safe in the short term. Dynesys reserves the mobility of pathological lumbar, ensures the stability of the posterior spine and corrects lumbar instability.