| Schmorl's nodes | |
|---|---|
| Other names | Intraosseous disk herniation, Schmorl's nodules |
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| X-ray image of Schmorl's nodes in the lumbar spine | |
| Specialty | Rheumatology  |
Schmorl's nodes are protrusions of the nucleus pulposus of the intervertebral disc through the vertebral body endplate and into the adjacent vertebra. [1]
These are protrusions of disc material into the surface of the vertebral body, which may contact the marrow of the vertebra and lead to inflammation. The protrusions are also associated with necrosis of the vertebral bone and the question of whether these protrusions and inflammation cause the necrosis, or whether the cartilage migrates into areas that have become necrotic due to other conditions, is under investigation.[ citation needed ]
They may or may not be symptomatic, and their link to back pain is controversial. Williams and colleagues note that this relationship may be due to lumbar disc disease, as the two commonly occur simultaneously. [2]
Schmorl's nodes are fairly common, especially with minor degeneration of the aging spine, but they are also seen in younger spines. Schmorl's nodes often cause no symptoms, but may simply reflect that "wear and tear" of the spine has occurred over time; they may also reflect that bone strength was at one time somewhat compromised, perhaps due to a vitamin D deficiency although this has yet to be confirmed with studies, or if heavy lifting is done at a young age before the vertebral bodies are completely ossified such as in young farm workers. There is also a strong heritability of Schmorl's Nodes (>70%). [2] While often non-complicating, Schmorl's nodes also tend to occur more often in cases of spinal deformity, specifically Scheuermann's disease. These defects are caused when the vertebra loses its normal function and is not moving/hypomobile/subluxated. During this time the forces normally distributed by the nucleus pulposus (the incompressible gelatinous center of the intervertebral disc) are concentrated in a certain area causing endplates to deform in a concave manner.[ citation needed ]
Schmorl's nodes can be detected with X-rays, although they can be imaged better by CT or MRI. They are considered to be vertical disc herniations through the cartilaginous vertebral body endplates. Schmorl's nodes can sometimes be seen radiographically, however they are more often seen on MRI, even when not visible on plain X-rays. They may or may not be symptomatic, and their etiological significance for back pain is controversial. In a study in Spine by Hamanishi, et al., Schmorl's nodes were observed on MRI in 19% of 400 patients with back pain, and in only 9% of an asymptomatic control group. The authors concluded that Schmorl's nodes are areas of "vertical disc herniation" through areas of weakness in the endplate. [4]
Painful Schmorl's node can be diagnosed by discography, which demonstrates an intravertebral disc herniation with concomitant back pain. Surgical treatment should be considered in a patient with persistent disabling back pain. When surgical treatment is indicated, eradication of the intervertebral disc including Schmorl's node and segmental fusion are preferable. [5]
Schmorl's nodes are named after German pathologist Christian Georg Schmorl (1861–1932). [6]
Lumbar disc disease is the drying out of the spongy interior matrix of an intervertebral disc in the spine. Many physicians and patients use the term lumbar disc disease to encompass several different causes of back pain or sciatica. In this article, the term is used to describe a lumbar herniated disc. It is thought that lumbar disc disease causes about one-third of all back pain.
Back pain is pain felt in the back. It may be classified as neck pain (cervical), middle back pain (thoracic), lower back pain (lumbar) or coccydynia based on the segment affected. The lumbar area is the most common area affected. An episode of back pain may be acute, subacute or chronic depending on the duration. The pain may be characterized as a dull ache, shooting or piercing pain or a burning sensation. Discomfort can radiate to the arms and hands as well as the legs or feet, and may include numbness or weakness in the legs and arms.
An intervertebral disc lies between adjacent vertebrae in the vertebral column. Each disc forms a fibrocartilaginous joint, to allow slight movement of the vertebrae, to act as a ligament to hold the vertebrae together, and to function as a shock absorber for the spine.
The lumbar vertebrae are, in human anatomy, the five vertebrae between the rib cage and the pelvis. They are the largest segments of the vertebral column and are characterized by the absence of the foramen transversarium within the transverse process and by the absence of facets on the sides of the body. They are designated L1 to L5, starting at the top. The lumbar vertebrae help support the weight of the body, and permit movement.
A discectomy is the surgical removal of abnormal disc material that presses on a nerve root or the spinal cord. The procedure involves removing a portion of an intervertebral disc, which causes pain, weakness or numbness by stressing the spinal cord or radiating nerves. The traditional open discectomy, or Love's technique, was published by Ross and Love in 1971. Advances have produced visualization improvements to traditional discectomy procedures, or endoscopic discectomy. In conjunction with the traditional discectomy or microdiscectomy, a laminotomy is often involved to permit access to the intervertebral disc. Laminotomy means a significant amount of typically normal bone is removed from the vertebra, allowing the surgeon to better see and access the area of disc herniation.
Lumbar spinal stenosis (LSS) is a medical condition in which the spinal canal narrows and compresses the nerves and blood vessels at the level of the lumbar vertebrae. Spinal stenosis may also affect the cervical or thoracic region, in which case it is known as cervical spinal stenosis or thoracic spinal stenosis. Lumbar spinal stenosis can cause pain in the low back or buttocks, abnormal sensations, and the absence of sensation (numbness) in the legs, thighs, feet, or buttocks, or loss of bladder and bowel control.
Back injuries result from damage, wear, or trauma to the bones, muscles, or other tissues of the back. Common back injuries include sprains and strains, herniated discs, and fractured vertebrae. The lumbar spine is often the site of back pain. The area is susceptible because of its flexibility and the amount of body weight it regularly bears. It is estimated that low-back pain may affect as much as 80 to 90 percent of the general population in the United States.
Spondylosis is the degeneration of the vertebral column from any cause. In the more narrow sense it refers to spinal osteoarthritis, the age-related degeneration of the spinal column, which is the most common cause of spondylosis. The degenerative process in osteoarthritis chiefly affects the vertebral bodies, the neural foramina and the facet joints. If severe, it may cause pressure on the spinal cord or nerve roots with subsequent sensory or motor disturbances, such as pain, paresthesia, imbalance, and muscle weakness in the limbs.
Degenerative disc disease (DDD) is a medical condition typically brought on by the normal aging process in which there are anatomic changes and possibly a loss of function of one or more intervertebral discs of the spine. DDD can take place with or without symptoms, but is typically identified once symptoms arise. The root cause is thought to be loss of soluble proteins within the fluid contained in the disc with resultant reduction of the oncotic pressure, which in turn causes loss of fluid volume. Normal downward forces cause the affected disc to lose height, and the distance between vertebrae is reduced. The anulus fibrosus, the tough outer layers of a disc, also weakens. This loss of height causes laxity of the longitudinal ligaments, which may allow anterior, posterior, or lateral shifting of the vertebral bodies, causing facet joint malalignment and arthritis; scoliosis; cervical hyperlordosis; thoracic hyperkyphosis; lumbar hyperlordosis; narrowing of the space available for the spinal tract within the vertebra ; or narrowing of the space through which a spinal nerve exits with resultant inflammation and impingement of a spinal nerve, causing a radiculopathy.
A retrolisthesis is a posterior displacement of one vertebral body with respect to the subjacent vertebra to a degree less than a luxation (dislocation). Retrolistheses are most easily diagnosed on lateral x-ray views of the spine. Views where care has been taken to expose for a true lateral view without any rotation offer the best diagnostic quality.
Cauda equina syndrome (CES) is a condition that occurs when the bundle of nerves below the end of the spinal cord known as the cauda equina is damaged. Signs and symptoms include low back pain, pain that radiates down the leg, numbness around the anus, and loss of bowel or bladder control. Onset may be rapid or gradual.
Congenital vertebral anomalies are a collection of malformations of the spine. Most, around 85%, are not clinically significant, but they can cause compression of the spinal cord by deforming the vertebral canal or causing instability. This condition occurs in the womb. Congenital vertebral anomalies include alterations of the shape and number of vertebrae.
Failed back syndrome or post-laminectomy syndrome is a condition characterized by chronic pain following back surgeries. Many factors can contribute to the onset or development of FBS, including residual or recurrent spinal disc herniation, persistent post-operative pressure on a spinal nerve, altered joint mobility, joint hypermobility with instability, scar tissue (fibrosis), depression, anxiety, sleeplessness, spinal muscular deconditioning and even Cutibacterium acnes infection. An individual may be predisposed to the development of FBS due to systemic disorders such as diabetes, autoimmune disease and peripheral blood vessels (vascular) disease.
A spinal disc herniation is an injury to the cushioning and connective tissue between vertebrae, usually caused by excessive strain or trauma to the spine. It may result in back pain, pain or sensation in different parts of the body, and physical disability. The most conclusive diagnostic tool for disc herniation is MRI, and treatment may range from painkillers to surgery. Protection from disc herniation is best provided by core strength and an awareness of body mechanics including posture.
Lumbar provocative discography is an invasive diagnostic procedure for evaluation for intervertebral disc pathology. It is usually reserved for persons with persistent, severe low back pain (LBP) who have abnormal spaces between vertebrae on magnetic resonance imaging (MRI), where other diagnostic tests have failed to reveal clear confirmation of a suspected disc as the source of pain, and surgical intervention is being considered.
A disc protrusion is a medical condition that can occur in some vertebrates, including humans, in which the outermost layers of the anulus fibrosus of the intervertebral discs of the spine are intact but bulge when one or more of the discs are under pressure.
Modic changes are pathological changes in the bones of the spine, the vertebrae. These changes are situated in both the body of the vertebrae and in the end plate of the neighboring disc. Clinically, Modic Changes are often associated with constant lower back pain during the day, with peak pain occurring during the night and in the morning, coupled with back stiffness.
The vertebral column, also known as the backbone or spine, is the core part of the axial skeleton in vertebrate animals. The vertebral column is the defining characteristic of vertebrate endoskeleton in which the notochord found in all chordates has been replaced by a segmented series of mineralized irregular bones called vertebrae, separated by fibrocartilaginous intervertebral discs. The dorsal portion of the vertebral column houses the spinal canal, a cavity formed by alignment of the neural arches that encloses and protects the spinal cord.
Astronauts have expressed an increased incidence of back pain during spaceflight and herniated intervertebral discs (IVD) have been diagnosed upon return of Skylab and Shuttle spaceflight participants.
Each vertebra is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal segment and the particular species.
