Herniated nucleus pulposus (slipped disk) The disks between the vertebrae are liable to displacement when put under strain. Heavy lifting may produce forces which cause a lumbar intervertebral disk to move out of place (“slipped disk”).
Your backbone, or spine, is made up of 26 bones called vertebrae. In between them are soft disks filled with a jelly-like substance. These disks cushion the vertebrae and keep them in place. As you age, the disks break down or degenerate. As they do, they lose their cushioning ability. This can lead to pain if the back is stressed.
A herniated disk is a disk that ruptures. This allows the jelly-like center of the disk to leak, irritating the nearby nerves. This can cause sciatica or back pain.
Your doctor will diagnose a herniated disk with a physical exam and, sometimes, imaging tests. With treatment, most people recover. Treatments include rest, pain and anti-inflammatory medicines, physical therapy, and sometimes surgery.
Spinal disc herniation (in Latin prolapsus disci intervertebralis, commonly called a slipped disc) is a medical condition affecting the spine in which a tear in the outer, fibrous ring (anulus fibrosus) of an intervertebral disc (discus intervertebralis) allows the soft, central portion (nucleus pulposus) 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 anulus fibrosus are still intact, but can bulge when the disc is under pressure. In contrast to a herniation, none of the nucleus pulposus 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 surgical intervention. 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”.
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. However, during growth, one vertebral body can slip relative to an adjacent vertebral body. This congenital deformity is called spondylolisthesis.
Most authors favor degeneration of the intervertebral disc as the major cause of spinal disc herniation and cite trauma as a low cause. With degeneration the contents of the disc, the nucleus pulposus and anulus fibrosus, are exposed to altered loads. Specifically, the nucleus becomes fibrous and stiff and less able to bear load. The load is transferred to the anulus which, if it fails to bear the increased load, can lead to the development of fissures. If the fissures reach the periphery of the anulus, the nuclear material can pass through as a disc herniation.
Disc herniations can result from general wear and tear, such as when performing jobs that require constant sitting and squatting or driving (sedentary lifestyle). However, herniations often result from jobs that require lifting. Professional athletes, especially those playing contact sports, are prone to disc herniations. Minor back pain and chronic back tiredness are indicators of general wear and tear that make one susceptible to herniation on the occurrence of a traumatic event, such as bending to pick up a pencil or falling.