Abstract:

BACKGROUND: The relationship between biomechanical factors and low back pain has been extensively studied in recent years, but mostly focus on unitary biomechanics characters and low back pain. There are few studies with regard to partial biomechanical factors and L5/S1 disc herniation.
OBJECTIVE: To explore the role of biomechanical factors in pathogenesis of L5/S1 disc herniation. 
METHODS: Totally 124 cases were included in the study. All cases were divided into the disc herniation group and control groups, with 62 cases in each group. The disc herniation group consisted of L₅/S₁ herniation patients received treatment at the Affiliated Hospital of Medical College of Oingdao University, and the healthy examination cases were served as controls. The indicator included relative depth of lumbar 5 vertebra, lumbosacral transitional vertebra, relative height of L₅/S₁ disc, lumbosacral angle, sacral horizon angle and sacral Inclination angle. The difference of the indicators between the two groups was analyzed statistically. 
RESULTS AND CONCLUSION: The relative depth of L₅ vertebra of the disc heniation group was significantly higher than the control group (P < 0.01), and the number of lumbosacral transitional vertebra of disc heniation group was significantly fewer than the control group (P < 0.01), which indicated that the deep-seated lumbar 5 vertebra and lumbosacral transitional vertebra might protect L₅/S₁ disc and reduce the incidence of L₅/S₁ disc herniation. Lumbosacral angle and sacral horizon angle of disc herniation group were significantly lower than that of control group (P < 0.01), but there was no significant statistical sense in the difference of sacral inclination angle between the two groups (P > 0.05), and there was no significant statistical sense in the difference of relative height of L₅/S₁ disc (P > 0.05), which indicated the roles of relative height of L₅/S₁ disc, lumbosacral angle, sacral horizon angle and sacral inclination angle in L₅/S₁ disc herniation still need further study.