(2) The annulus fibrosus of the posterolateral intervertebral disc is weak, and the width of the posterior longitudinal ligament in the plane of the fifth lumbar vertebra and the 1 sacral vertebra is obviously reduced, so the reinforcement effect on the annulus fibrosus is obviously weakened;
(3) Congenital abnormality of lumbosacral segment: Lumbosacral segment deformity can increase the incidence rate, including lumbosacral sacralization, lumbosacral deformity, hemivertebra deformity, facet joint deformity, and asymmetry of articular process. These abnormalities often cause the width of intervertebral space to be unequal, and often make the articular process bear more rotational strain, so that the fibrous ring bears different pressures and accelerates degeneration. Please look for the "crabgrass" trademark for medical treatment, and beware of being deceived.
(4) Ethnic and genetic factors: The incidence of colored people, such as Indians and African blacks, is lower than that of other races. About 32% of adolescent patients under 20 years old have family history.