From the Disc Herniation to the Stenosis of the Lumbar Canal

From the disc herniation to the canal stenosis is walking along the life and following the road of degeneration. But recent studies has improved the understanding of this process and the treatment.Embryology: During the 21 first days: the constitution of the vertebrae comes from the mesoderm: 2 events are major the segmentation and the "re-segmentation", after these steps the chondrification and the ossification continue the formation of the entire spine, the diameter of the canal is determined during the primary ossification. Anatomy: The bio-mecanique has been studied by Panjabi and completed by histologic and immunologic work which have permitted to understand the behavior of the vertebral unit.Pathogenesis of the disc degeneration:-Two concepts have been develop: The biomecanic concept: the nucleus received stress in compression, conversely the fibrosus in tension.-Immunologic concept: in vitro, disc cells have been studiy: evidence of inflammatory chain is demonstrated with activation of metalloprotease which plays a role in the alteration of peri-cell matrix.But in fact the 2 mechanism are complementary explaining the MRI aspect of Modic I.Treatment of disc herniation: Treatment of disc herniation is not univocal, treatment is only imposed in case of handicap. Medical treatment is always necessary (except in case of paralysis), surgery is indicated in case of failure of medical treatment well followed, after at least 6 weeks with perfect concordance between clinic and images. A simple diskectomy is sufficient to obtain an excellent result.Treatment of Low back pain: Much complex, the treatment is essentially medical, indication for surgery must be very targeted.Canal stenosis: It is the normal consequences of slow degeneration mechanism. Clinical expression result from incompatibility between the contents and the container. De Seze after Verbiest described the stenosis due to degenerative changes. But other phenomenon are implicated in this expression as inflammatory, vascular and general condition. The treatment must start by medical care, indication for surgery is kept only in case of failure and persistence of handicap. Surgery may be decompresssion alone, fixation and fusion or both. Technique depends on level of the lesion, presence or not of instability, deformity (more or less flexible). However, these patients are frequently old but very active, comorbidities may be associated, the risk of surgery must be clearly evaluated.Conclusion: Degenerative change of the spine is a normal phenomenon, conservative attitude must be the gold standard.