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Spinal disc herniation, also known as a slipped disc, is a medical condition affecting the spine in which a tear in the outer, fibrous ring of an intervertebral disc allows the soft, central portion to bulge out beyond the damaged outer rings. Disc herniation is usually due to age-related degeneration of the anulus fibrosus, although trauma, lifting injuries, or straining have been implicated. Tears are almost always postero-lateral in nature owing to the presence of the posterior longitudinal ligament in the spinal canal. This tear in the disc ring may result in the release of inflammatory chemical mediators, which may directly cause severe pain, even in the absence of nerve root compression. Disc herniations are normally a further development of a previously existing disc "protrusion", a condition in which the outermost layers of the fibrous ring are still intact, but can bulge when the disc is under pressure. In contrast to a herniation, none of the central portion escapes beyond the outer layers. Most minor herniations heal within several weeks. Anti-inflammatory treatments for pain associated with disc herniation, protrusion, bulge, or disc tear are generally effective. Severe herniations may not heal of their own accord and may require surgery. The condition is widely referred to as a ''slipped disc'', but this term is not medically accurate as the spinal discs are firmly attached between the vertebrae and cannot "slip". == Terminology == Some of the terms commonly used to describe the condition include ''herniated disc'', ''prolapsed disc'', ''ruptured disc'' and ''slipped disc''. Other phenomena that are closely related include disc protrusion, pinched nerves, sciatica, disc disease, disc degeneration, degenerative disc disease, and black disc. The popular term ''slipped disc'' is a misnomer, as the intervertebral discs are tightly sandwiched between two vertebrae to which they are attached, and cannot actually "slip", or even get out of place. The disc is actually grown together with the adjacent vertebrae and can be squeezed, stretched and twisted, all in small degrees. It can also be torn, ripped, herniated, and degenerated, but it cannot "slip". Some authors consider that the term "slipped disc" is harmful, as it leads to an incorrect idea of what has occurred and thus of the likely outcome.〔(【引用サイトリンク】title=Prolapsed disc )〕〔Ehealthmd.com (FAQ: "...the entire disc does not 'slip' out of place." )〕〔 However, during growth, one vertebral body can slip relative to an adjacent vertebral body. This congenital deformity is called spondylolisthesis. ; Click images to see larger versions File:Lumbar Disc Lesions, Classification by Harry Gouvas.jpg|Lumbar disc lesions, classification File:ACDF coronal english.png|Normal situation and spinal disc herniation in cervical vertebrae. File:Herniated Disc.png|Illustration depicting herniated disc and spinal nerve compression File:Disc prolapse.png|Nucleus herniating through tear in anulus (with MRI)〔Anjankar SD, Poornima S, Raju S, Jaleel M, Bhiladvala D, Hasan Q. Degenerated intervertebral disc prolapse and its association of collagen I alpha 1 Spl gene polymorphism: A preliminary case control study of Indian population. Indian J Orthop 2015;49:589-94〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Spinal disc herniation」の詳細全文を読む スポンサード リンク
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