BACKGROUND:Discectomy and pedicle fixation fusion are golden standard to repair lumbar degenerative disease, but the treatment would induce other complications such as degeneration of adjacent segments or severer pre-existing spinal degeneration. For the problem of lumbar fusion and fixation, lumbar elastic fixation has recently been a hot focus. ＜br> OBJECTIVE:To evaluate the short-term effectiveness of dynamic lumbar pedicle fixation in repair of lumbar spinal stenosis and lumbar disc herniation. ＜br> METHODS:From December 2010 to December 2012, 62 cases of lumbar spinal stenosis and lumbar disc herniation treated with lumbar dynamic system were included. The involved segments included:5 cases at L 3/4 , 20 cases at L 4/5 , 20 cases at L 5 S 1 , 6 cases at double segment L 3/4 and L 4/5, 8 cases at double segment L 4/5 , L 5 S 1 , 3 cases at L 3/4 and L 5 S 1 . There were 34 males and 28 females with an average age of 50.8 years (range 32 to 72 years). According to different fixation systems, they were assigned to three groups:general dynamic lumbar fixation system in 17 cases, K-Rod posterior dynamic stabilization system in 28 cases, and Dynesys system in 17 cases. The fol ow-up time was from 24 to 48 months. Evaluation indexes included visual analogue scale, Oswestry disability index, imaging analysis and excellent and good rate of curative effects. ＜br> RESULTS AND CONCLUSION:Compared with before treatment, visual analogue scale score and Oswestry disability index were significantly improved at 6 months after treatment and final fol ow-up (P＜0.01). No apparent changes were detected in the length of inserted segments and adjacent segments before treatment and during final fol ow-up. There were no significant differences in the excellent and good rate in each group after treatment (P>0.05). These data indicated that the lumbar dynamic system was an effective option for lumbar disc herniation and spinal stenosis. Although there are some differences in the structure of three kinds of flexible fixation, no obvious difference in early therapeutic effects was detected. Long-term effects deserve further investigations.