Spondylosis is a broad term meaning degeneration of the spinal column from any cause. In the more narrow sense it refers to spinal osteoarthrosis, the age-related wear and tear 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 (facet syndrome). 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.

When the space between two adjacent vertebrae narrows, compression of a nerve root emerging from the spinal cord may result in radiculopathy (sensory and motor disturbances, such as severe pain in the neck, shoulder, arm, back, or leg, accompanied by muscle weakness). Less commonly, direct pressure on the spinal cord (typically in the cervical spine) may result in myelopathy, characterized by global weakness, gait dysfunction, loss of balance, and loss of bowel or bladder control. The patient may experience shocks (paresthesia) in hands and legs because of nerve compression and lack of blood flow. If vertebrae of the neck are involved it is labelled cervical spondylosis. Lower back spondylosis is labeled lumbar spondylosis. The term is from Ancient Greek σπόνδυλος "spóndylos", "a vertebra", in plural "vertebrae – the backbone".

Including the symptoms listed above, clinical presentations of "wobblers" can also include neck pain and stiffness, difficulty tracking up or gait abnormalities, decreased performance, intermittent or swapping lameness particularly in diagonal pairs, forelimb lameness, abnormal head and neck posture, defensiveness or change in behavior, and abnormal sweat patterns.

Wobbler disease is probably inherited in the Borzoi, Great Dane, Doberman, and Basset Hound. Instability of the vertebrae of the neck (usually the caudal neck) causes spinal cord compression. In younger dogs such as Great Danes less than two years of age, wobbler disease is caused by stenosis (narrowing) of the vertebral canal related to degeneration of the dorsal articular facets and subsequent thickening of the associated joint capsules and ligaments. A high-protein diet may contribute to its development. In middle-aged and older dogs such as Dobermans, intervertebral disc disease leads to bulging of the disc or herniation of the disc contents, and the spinal cord is compressed. In Great Danes, the C to C vertebrae are most commonly affected; in Dobermans, the C to C vertebrae are affected.

The disease tends to be gradually progressive. Symptoms such as weakness, ataxia, and dragging of the toes start in the rear legs. Dogs often have a crouching stance with a downward flexed neck. The disease progresses to the front legs, but the symptoms are less severe. Neck pain is sometimes seen. Symptoms are usually gradual in onset, but may progress rapidly following trauma. X-rays may show misaligned vertebrae and narrow disk spaces, but it is not as effective as a myelogram, which reveals stenosis of the vertebral canal. Magnetic resonance imaging has been shown to be more effective at showing the location, nature, and severity of spinal cord compression than a myelogram. Treatment is either medical to control the symptoms, usually with corticosteroids and cage rest, or surgical to correct the spinal cord compression. The prognosis is guarded in either case. Surgery may fully correct the problem, but it is technically difficult and relapses may occur. Types of surgery include ventral decompression of the spinal cord (ventral slot technique), dorsal decompression, and vertebral stabilization. One study showed no significant advantage to any of the common spinal cord decompression procedures. Another study showed that electroacupuncture may be a successful treatment for Wobbler disease. A new surgical treatment using a proprietary medical device has been developed for dogs with disc-associated wobbler disease. It implants an artificial disc (cervical arthroplasty) in place of the affected disc space.

The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral column is the defining characteristic of a vertebrate, in which the notochord (a flexible rod of uniform composition) found in all chordates has been replaced by a segmented series of bones—vertebrae separated by intervertebral discs. The vertebral column houses the spinal canal, a cavity that encloses and protects the spinal cord.

There are about 50,000 species of animals that have a vertebral column. The human vertebral column is one of the most-studied examples.

A spinal fracture, also called a vertebral fracture or a broken back, is a fracture affecting the vertebrae of the spinal column. Most types of spinal fracture confer a significant risk of spinal cord injury. After the immediate trauma, there is a risk of spinal cord injury (or worsening of an already injured spine) if the fracture is "unstable", that is, likely to change alignment without internal or external fixation.

Vertebral fractures of the thoracic vertebrae, lumbar vertebrae or sacrum are usually associated with major trauma and can cause spinal cord injury that results in a neurological deficit.

Baastrup's sign, or kissing spine, is an orthopedic and radiographic disorder that often occurs in elderly humans. It is characterized by enlargement of the posterior spinous projections of the lumbar spine, with normal intervertebral disc height and neuroforamina. The reason it is referred to as "kissing spine" is because the posterior spinous processes 'kiss' and touch one another as the individual goes into lumbar extension, for example when flat on their stomach. The condition has been seen in humans, canines, particularly with boxer breeds, and certain breeds of horses. This disorder is named after Christian Ingerslev Baastrup.

A retrolisthesis is a posterior displacement of one vertebral body with respect to the subjacent vertebra to a degree less than a luxation (dislocation). Clinically speaking, retrolisthesis is the opposite of spondylolisthesis (anterior displacement of one vertebral body on the subjacent vertebral body), and is also called retrospondylolisthesis. 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.

Retrolistheses are found most prominently in the cervical spine and lumbar region but can also be seen in the thoracic area.

There are multiple techniques used in the diagnosis of spondylosis, these are;

- Cervical Compression Test, a variant of Spurling's test, is performed by laterally flexing the patient's head and placing downward pressure on it. Neck or shoulder pain on the ipsilateral side (i.e. the side to which the head is flexed) indicates a positive result for this test. However it should be noted that a positive test result is not necessarily a positive result for spondylosis and as such additional testing is required.

- Lhermitte sign: feeling of electrical shock with patient neck flexion

- Reduced range of motion of the neck, the most frequent objective finding on physical examination

- MRI and CT scans are helpful for pain diagnosis but generally are not definitive and must be considered together with physical examinations and history.

Excessive or abnormal spinal curvature is classed as a spinal disease or dorsopathy and includes the following abnormal curvatures:

- Kyphosis is an exaggerated kyphotic (concave) curvature in the thoracic region, also called hyperkyphosis. This produces the so-called "humpback" or "dowager's hump", a condition commonly resulting from osteoporosis.

- Lordosis as an exaggerated lordotic (convex) curvature of the lumbar region, is known as lumbar hyperlordosis and also as "swayback". Temporary lordosis is common during pregnancy.

- Scoliosis, lateral curvature, is the most common abnormal curvature, occurring in 0.5% of the population. It is more common among females and may result from unequal growth of the two sides of one or more vertebrae, so that they do not fuse properly. It can also be caused by pulmonary atelectasis (partial or complete deflation of one or more lobes of the lungs) as observed in asthma or pneumothorax.

- Kyphoscoliosis, a combination of kyphosis and scoliosis.

Retrolisthesis may lead to symptoms of greatly varying intensity and distribution. This is because of the variable nature of the impact on nerve tissue and of the mechanical impact on the spinal joints themselves.

Structural instability may be Experienced as a local uneasiness through to a more far reaching structural compensatory distortion involving the whole spine. If the joints are stuck in a retrolisthesis configuration there may also be changes to range of motion.

Pain may be experienced as a result of irritation to the sensory nerve roots by bone depending on the degree of displacement and the presence of any rotatory positioning of the individual spinal motion segments. The soft tissue of the disc is often caused to bulge in retrolistheses. These cannot be determined by plain films, as the x-ray passes through the soft tissue. A study by Giles et al., stated that Sixteen of the thirty patients (53%) had retrolisthesis of L5 on S1 ranging from 2–9 mm; these patients had either intervertebral disc bulging or protrusion on CT examination ranging from 3–7 mm into the spinal canal. Fourteen patients (47%) without retrolisthesis (control group) did not show any retrolisthesis and the CT did not show any bulge/protrusion. On categorizing x-ray and CT pathology as being present or not, the well positioned i.e. true lateral plain x-ray film revealed a sensitivity and specificity of 100% ([95% Confidence Interval. = [89%–100%]) for bulge/protrusion in this preliminary study.” ()

Spinal cord compressions are also possible with patients experiencing pain, rigidity and neurologic signs that may follow some distance along nerves to cause symptoms at some distance from the location of the retrolisthesis.

The salient feature of the disorder is the exuberant osteophytosis that occurs at posterior lumbar spinous processes. Osteophytes are coarse calcifications at the edges of bone that form due to repetitive stress and trauma. There is also atrophy and fatty replacement of paraspinal musculature, which can be detected by CT or MRI.

Scoliosis is a common spinal disease in which the spine has a curvature usually in the shape of the letter "C" or "S". This is most common in girls, but there is no specific cause for scoliosis. Only a few symptoms occur for one with this disease, which include feeling tired in the spinal region or backaches. Generally, if the hips or shoulders are uneven, or if the spine curves, it is due to scoliosis and should be seen by a doctor.

Lumbar spinal stenosis is classified as a narrowing of the spinal canal in the lumbar region of the vertebrae. This may lead to compression of the nerve root of the spinal cord and result in pain of the lower back and lower extremities. Other symptoms include impaired walking and a slightly stooped posture due to loss of disc height and bulging of the disc. Lumbar spinal stenosis is very prevalent with 9.3% of the general population producing symptoms and the number is continuing to rise in patients older than 60. It's generally an indication for spinal surgery in patients older than 65 years of age.

A burst fracture is a type of traumatic spinal injury in which a vertebra breaks from a high-energy axial load (e.g., traffic collisions or falls from a great height or high speed, and some kinds of seizures), with shards of vertebra penetrating surrounding tissues and sometimes the spinal canal. The burst fracture is categorized by the ""severity of the deformity, the severity of" (spinal) "canal compromise, the degree of loss of vertebral body height, and the degree of neurologic deficit."" Burst fractures are considered more severe than compression fractures because long-term neurological damage can follow. The neurologic deficits can reach their full extent immediately, or can progress for a prolonged time.

Understanding the meaning of signs and symptoms for the clinical syndrome of lumbar stenosis requires an understanding of what the syndrome is, and the prevalence of the condition. A recent review on lumbar stenosis in the Journal of the American Medical Association's "Rational Clinical Examination Series" emphasized that the syndrome can be considered when lower extremity pain occurs in combination with back pain. This syndrome occurs in 12% of older community dwelling men and up to 21% of those in retirement communities.

The leg symptoms in lumbar spinal stenosis (LSS) are similar to those found with vascular claudication, giving rise to the term pseudoclaudication. These symptoms include pain, weakness, and tingling of the legs, which may radiate down the leg to the feet. Additional symptoms in the legs may be fatigue, heaviness, weakness, a sensation of tingling, pricking, or numbness and leg cramps, as well as bladder symptoms. Symptoms are most commonly bilateral and symmetrical, but they may be unilateral; leg pain is usually more troubling than back pain.

Pseudoclaudication, now referred to as neurogenic claudication, typically worsen with standing or walking and improve with sitting. The occurrence is often related to posture and lumbar extension. Lying on the side is often more comfortable than lying flat, since it permits greater lumbar flexion. Vascular claudication can resemble spinal stenosis, and some individuals experience unilateral or bilateral symptoms radiating down the legs rather than true claudication.

The first symptoms of stenosis include bouts of low back pain. After a few months or years, this may progress to claudication. The pain may be radicular, following the classic neurologic pathways. This occurs as the spinal nerves or spinal cord become increasingly trapped in a smaller space within the canal. It can be difficult to determine whether pain in the elderly is caused by lack of blood supply or stenosis; testing can usually differentiate between them but patients can have both vascular disease in the legs and spinal stenosis.

Among people with lower extremity pain in combination with back pain, lumbar stenosis as the cause is two times more likely in those older than 70 years of age while those younger than 60 years it is 0.40 as likely. The character of the pain is also useful. When the discomfort does not occur while seated, the likelihood of LSS increases considerably around 7.4 times. Other features increasing the likelihood of lumbar stenosis are improvement in symptoms on bending forward 6.4 times, pain that occurs in both buttocks or legs 6.3 times, and the presence of neurogenic claudication 3.7 times. Alternately, the absence of neurogenic claudication makes lumbar stenosis much less likely as the explanation for the pain.

Symptoms of a herniated disc can vary depending on the location of the herniation and the types of soft tissue that become involved. They can range from little or no pain if the disc is the only tissue injured, to severe and unrelenting neck or lower back pain that will radiate into the regions served by affected nerve roots that are irritated or impinged by the herniated material. Often, herniated discs are not diagnosed immediately, as the patients come with undefined pains in the thighs, knees, or feet. Other symptoms may include sensory changes such as numbness, tingling, paresthesia, and motor changes such as muscular weakness, paralysis and affection of reflexes. If the herniated disc is in the lumbar region the patient may also experience sciatica due to irritation of one of the nerve roots of the sciatic nerve. Unlike a pulsating pain or pain that comes and goes, which can be caused by muscle spasm, pain from a herniated disc is usually continuous or at least is continuous in a specific position of the body. It is possible to have a herniated disc without any pain or noticeable symptoms, depending on its location. If the extruded nucleus pulposus material doesn't press on soft tissues or nerves, it may not cause any symptoms. A small-sample study examining the cervical spine in symptom-free volunteers has found focal disc protrusions in 50% of participants, which suggests that a considerable part of the population can have focal herniated discs in their cervical region that do not cause noticeable symptoms.

A prolapsed disc in the lumbar spine can cause radiating nerve pain. This type of pain is usually felt in the lower extremities or groin area. Radiating nerve pain caused by a prolapsed disc can also cause bowel and bladder incontinence.

Typically, symptoms are experienced only on one side of the body. If the prolapse is very large and presses on the nerves within the spinal column or the cauda equina, both sides of the body may be affected, often with serious consequences. Compression of the cauda equina can cause permanent nerve damage or paralysis. The nerve damage can result in loss of bowel and bladder control as well as sexual dysfunction. This disorder is called cauda equina syndrome.

Other complications include chronic pain.

Lumbar spinal stenosis (LSS) is a medical condition in which the spinal canal narrows and compresses the nerves at the level of the lumbar vertebrae. This is usually due to the common occurrence of spinal degeneration that occurs with aging. It can also sometimes be caused by spinal disc herniation, osteoporosis, a tumor, or trauma. In the cervical (neck) and lumbar (low back) region it can be a congenital condition to varying degrees.

It is also a common symptom for those who suffer from various skeletal dysplasias such as with pseudoachondroplasia and achondroplasia at an early age.

Spinal stenosis may affect the cervical or thoracic region in which case it is known as cervical spinal stenosis or thoracic spinal stenosis. In some cases, it may be present in all three places in the same patient. Lumbar spinal stenosis can cause low back pain, abnormal sensations, and the absence of sensation (numbness) in the legs, thighs, feet or buttocks, or loss of bladder and bowel control.

Traditionally there have been 5 components that form the chiropractic subluxation. The vertebral subluxation complex is differentiated by the fifth component, general systemic disturbances secondary to the spinal misalignment (vertebral subluxation).

1. Spinal Kinesiopathology

2. Neuropathophysiology/Neuropathology

3. Myopathology

4. Histopathology

5. Pathophysiology/Pathology

Cervical spinal stenosis is a bone disease involving the narrowing of the spinal canal at the level of the neck. It is frequently due to chronic degeneration, but may also be congenital. Treatment is frequently surgical.

Cervical spinal stenosis is one of the most common forms of spinal stenosis, along with lumbar spinal stenosis (which occurs at the level of the lower back instead of in the neck). Thoracic spinal stenosis, at the level of the mid-back, is much less common. Cervical spinal stenosis can be far more dangerous by compressing the spinal cord. Cervical canal stenosis may lead to serious symptoms such as major body weakness and paralysis. Such severe spinal stenosis symptoms are virtually absent in lumbar stenosis, however, as the spinal cord terminates at the top end of the adult lumbar spine, with only nerve roots (cauda equina) continuing further down. Cervical spinal stenosis is a condition involving narrowing of the spinal canal at the level of the neck. It is frequently due to chronic degeneration, but may also be congenital or traumatic. Treatment frequently is surgical.

Historically, the detection of spinal misalignments (subluxations) by the chiropractic profession has relied on X-ray findings and physical examination. At least 2 of the following 4 physical signs and/or symptoms must be documented to qualify for reimbursement:

- Pain and tenderness

- Asymmetry/misalignment

- Range of motion abnormality

- Tissue/tone changes

The onset of myelomalacia may be so subtle that it is overlooked. Depending on the extent of the spinal cord injury, the symptoms may vary. In some cases, the symptom may be as common as hypertension. Though every case is different, several cases reported loss of motor functions in the extremities, areflexia or sudden jerks of the limbs, loss of pain perception, or even paralysis; all of which are possible indicators of a damaged and softened spinal cord. In the most severe cases, paralysis of the respiratory system manifests in death.

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, a deformity called spondylolisthesis.

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The signs and symptoms of diastematomyelia may appear at any time of life, although the diagnosis is usually made in childhood. Cutaneous lesions (or stigmata), such as a hairy patch, dimple, Hemangioma, subcutaneous mass, Lipoma or Teratoma override the affected area of the spine is found in more than half of cases. Neurological symptoms are nonspecific, indistinguishable from other causes of cord tethering. The symptoms are caused by tissue attachments that limit the movement of the spinal cord within the spinal column. These attachments cause an abnormal stretching of the spinal cord.

The course of the disorder is progressive. In children, symptoms may include the "stigmata" mentioned above and/or foot and spinal deformities; weakness in the legs; low back pain; scoliosis; and incontinence. In adulthood, the signs and symptoms often include progressive sensory and motor problems and loss of bowel and bladder control. This delayed presentation of symptoms is related to the degree of strain placed on the spinal cord over time.

Tethered spinal cord syndrome appears to be the result of improper growth of the neural tube during fetal development, and is closely linked to spina bifida.

Tethering may also develop after spinal cord injury and scar tissue can block the flow of fluids around the spinal cord. Fluid pressure may cause cysts to form in the spinal cord, a condition called syringomyelia. This can lead to additional loss of movement, feeling or the onset of pain or autonomic symptoms.

Cervical diastematomyelia can become symptomatic as a result of acute trauma, and can cause major neurological deficits, like hemiparesis, to result from otherwise mild trauma.

The following definitions may help to understand some of the related entities:

- Diastematomyelia (di·a·stem·a·to·my·elia) is a congenital anomaly, often associated with spina bifida, in which the spinal cord is split into halves by a bony spicule or fibrous band, each half being surrounded by a dural sac.

- Myeloschisis (my·elos·chi·sis) is a developmental anomaly characterized by a cleft spinal cord, owing to failure of the neural plate to form a complete neural tube or to rupture of the neural tube after closure.

- Diplomyelia (diplo.my.elia) is a true duplication of spinal cord in which these are two dural sacs with two pairs of anterior and posterior nerve roots.

Myelomalacia is a pathological term referring to the softening of the spinal cord. Hemorrhagic infarction (bleeding) of the spinal cord can occur as a sequela to acute injury, such as that caused by intervertebral disc extrusion (being forced or pressed out).

The disorder causes flaccid paraplegia (impairment of motor function in lower extremities), total areflexia (below normal or absence of reflexes) of the pelvic limbs and anus, loss of deep pain perception caudal (toward the coccyx, or tail) to the site of spinal cord injury, muscular atrophy (wasting away of muscle tissue), depressed mental state, and respiratory difficulty due to intercostal (muscles that run between the ribs) and diaphragmatic paralysis. Gradual cranial migration of the neurological deficits (problems relating to the nervous system), is known as ascending syndrome and is said to be a typical feature of diffuse myelomalacia. Although clinical signs of myelomalacia are observed within the onset (start) of paraplegia, sometimes they may become evident only in the post-operative period, or even days after the onset of paraplegia. Death from myelomalacia may occur as a result of respiratory paralysis when the ascending lesion (abnormal damaged tissue) reaches the motor nuclei of the phrenic nerves (nerves between the C3-C5 region of the spine) in the cervical (neck) region.