Hemivertebrae are wedge-shaped vertebrae and therefore can cause an angle in the spine (such as kyphosis, scoliosis, and lordosis).

Among the congenital vertebral anomalies, hemivertebrae are the most likely to cause neurologic problems. The most common location is the midthoracic vertebrae, especially the eighth (T8). Neurologic signs result from severe angulation of the spine, narrowing of the spinal canal, instability of the spine, and luxation or fracture of the vertebrae. Signs include rear limb weakness or paralysis, urinary or fecal incontinence, and spinal pain. Most cases of hemivertebrae have no or mild symptoms, so treatment is usually conservative. Severe cases may respond to surgical spinal cord decompression and vertebral stabilization.

Associations

Recognised associations are many and include:

Aicardi syndrome,

cleidocranial dysostosis,

gastroschisis 3,

Gorlin syndrome,

fetal pyelectasis 3,

Jarcho-Levin syndrome,

OEIS complex,

VACTERL association.

The probable cause of hemivertebrae is a lack of blood supply causing part of the vertebrae not to form.

Hemivertebrae in dogs are most common in the tail, resulting in a screw shape.

Vertebral anomalies is associated with an increased incidence of some other specific anomalies as well, together being called the VACTERL association:

- V - "Vertebral anomalies"

- A - Anal atresia

- C - Cardiovascular anomalies

- T - Tracheoesophageal fistula

- E - Esophageal atresia

- R - Renal (Kidney) and/or radial anomalies

- L - Limb defects

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.

The following are clear signs of Kyphoscoliosis:

- Abnormal hunch along with a presence of S or C-like shape.

- Uneven lengths of arms and legs

- Presence of associated disorders likes hypertension, neurological disorders

- Abnormal gait

Kyphosis by itself refers to an excessive convex curvature of spine occurring in the thoracic and sacral regions. A normal thoracic curvature from the 1st to the 12th spine has a naturally occurring convex shape with angles ranging from 20 degrees to 45 degrees. When the curvature goes past 45 degrees, the condition is termed as Kyphosis.

Kyphosis, depending on the extent of curvature can result in many discomforts including breathing and digestion difficulties, cardiovascular issues, and even neurological deformities. The greater the extent of deformity, the more pressing the need becomes for a surgery.

Kyphosis by itself is of several types, including postural kyphosis caused by slouching. Such forms of kyphosis can be reversed to a certain extent by correcting muscular imbalances. The more debilitating version of kyphosis is Scheuermann’s kyphosis, found mostly in teenagers. There are few other causes of Kyphosis as well, such as congenital, nutritional or osteoporosis induced and post-traumatic.

Depending on the type of Kyphosis, the extent of curvature, the age of the patient, various treatment modalities can be suggested including the provision for posture correction, braces, physiotherapy for correcting the muscular imbalance, and finally the surgery. Surgery can be most useful in patients who have an extensive deformity. The rate of post-surgery complications may be higher in elderly patients.

Numerous associated abnormalities of other organ systems may be present. This heterogeneity requires comprehensive evaluation of all patients and treatment regimes that can vary from modification of activities to extensive spinal surgeries. Furthermore, it is unclear whether Klippel–Feil syndrome is a unique disease, or if it is one part of a spectrum of congenital spinal deformities. Klippel–Feil syndrome is usually diagnosed after birth.

The most common sign of the disorder is restricted mobility of the neck and upper spine. A short neck and low hairline at the back of the head may occur in some patients.

Associated abnormalities may include:

- scoliosis (side-to-side curvature of the spine), which is abnormal curving of the spine. The spine sometimes appears as a "C" or an "S"

- spina bifida, when the spinal canal and the back bone do not close completely during birth

- anomalies of the kidneys and the ribs

- cleft palate (hole in the roof of the mouth)

- dental problems (late dentition, high-risk of caries, oligo- and hypodontia)

- respiratory problems

- heart malformations

- short stature

- Duane syndrome

- Approximately 35% of patients with Klippel–Feil syndrome will also have a congenital elevation of the scapula known as Sprengel's deformity

The disorder also may be associated with abnormalities of the head and face, skeleton, sex organs, muscles, brain and spinal cord, arms, legs, fingers and heart defects. These heart defects often lead to a shortened life expectancy, the average being 35–45 years of age among males and 40–50 among females. This condition is similar to the heart failure seen in gigantism.

In 2011, a study identifying the occurrence of symptoms of 100 patients was published.

Diastematomyelia (occasionally diastomyelia) is a congenital disorder in which a part of the spinal cord is split, usually at the level of the upper lumbar vertebra.

Diastematomyelia is a rare congenital anomaly that results in the "splitting" of the spinal cord in a longitudinal (sagittal) direction. Females are affected much more commonly than males. This condition occurs in the presence of an osseous (bone), cartilaginous or fibrous septum in the central portion of the spinal canal which then produces a complete or incomplete sagittal division of the spinal cord into two hemicords. When the split does not reunite distally to the spur, the condition is referred to as a diplomyelia, or true duplication of the spinal cord.

Klippel–Feil syndrome is a rare disease, initially reported in 1884 by Maurice Klippel and André Feil from France, characterized by the congenital fusion of any two of the seven cervical vertebrae.

The syndrome occurs in a heterogeneous group of patients unified only by the presence of a congenital defect in the formation or segmentation of the cervical spine. Klippel-Feil results in limited movement of the neck. Klippel–Feil syndrome is sometimes identified by shortness of the neck, but not all people with this disorder have a visibly shortened neck. Some people with the syndrome have a very low hairline.

In 1919, in his PhD thesis, André Feil suggested another classification of the syndrome encompassing not only deformation of the cervical spine but also deformation of the lumbar and thoracic spine.

There are several kinds of kyphosis (ICD-10 codes are provided):

- Postural kyphosis (M40.0), the most common type, normally attributed to slouching, can occur in both the old and the young. In the young, it can be called "slouching" and is reversible by correcting muscular imbalances. In the old, it may be a case of hyperkyphosis and called "dowager's hump". About one third of the most severe hyperkyphosis cases in older people have vertebral fractures. Otherwise, the aging body does tend towards a loss of musculoskeletal integrity, and hyperkyphosis can develop due to aging alone.

- Scheuermann's kyphosis (M42.0) is significantly worse cosmetically and can cause varying degrees of pain, and can also affect different areas of the spine (the most common being the midthoracic area). Scheuermann's kyphosis is considered a form of juvenile osteochondrosis of the spine, and is more commonly called Scheuermann's disease. It is found mostly in teenagers and presents a significantly worse deformity than postural kyphosis. A patient suffering from Scheuermann’s kyphosis cannot consciously correct posture. The apex of the curve, located in the thoracic vertebrae, is quite rigid. The patient may feel pain at this apex, which can be aggravated by physical activity and by long periods of standing or sitting. This can have a significantly detrimental effect on their lives, as their level of activity is curbed by their condition; they may feel isolated or uneasy amongst peers if they are children, depending on the level of deformity. Whereas in postural kyphosis, the vertebrae and discs appear normal, in Scheuermann’s kyphosis, they are irregular, often herniated, and wedge-shaped over at least three adjacent levels. Fatigue is a very common symptom, most likely because of the intense muscle work that has to be put into standing or sitting properly. The condition appears to run in families. Most patients who undergo surgery to correct their kyphosis have Scheuermann's disease.

- Congenital kyphosis (Q76.4) can result in infants whose spinal column has not developed correctly in the womb. Vertebrae may be malformed or fused together and can cause further progressive kyphosis as the child develops. Surgical treatment may be necessary at a very early stage and can help maintain a normal curve in coordination with consistent follow-ups to monitor changes. However, the decision to carry out the procedure can be very difficult due to the potential risks to the child. A congenital kyphosis can also suddenly appear in teenage years, more commonly in children with cerebral palsy and other neurological disorders.

- Nutritional kyphosis can result from nutritional deficiencies, especially during childhood, such as vitamin D deficiency (producing rickets), which softens bones and results in curving of the spine and limbs under the child's body weight.

- Gibbus deformity is a form of structural kyphosis, often a "sequela" to tuberculosis.

- Post-traumatic kyphosis (M84.0) can arise from untreated or ineffectively treated vertebral fractures.

This condition exists in a variety of forms, ranging from partial absence of the tail bone regions of the spine to absence of the lower vertebrae, pelvis and parts of the thoracic and/or lumbar areas of the spine. In some cases where only a small part of the spine is absent, there may be no outward sign of the condition. In cases where more substantial areas of the spine are absent, there may be fused, webbed, or smaller lower extremities and paralysis. Bowel and bladder control is usually affected.

In children, symptoms may include:

- Lesions, hairy patches, dimples, or fatty tumours on the lower back

- Foot and spinal deformities

- Weakness in the legs (loss of muscle strength and tone)

- Change in or abnormal gait including awkwardness while running or wearing the tips or side of one shoe

- Low back pain

- Scoliosis (abnormal curvature of the spine to the left or right)

- Urinary irregularities (incontinence or retention)

Tethered spinal cord syndrome may go undiagnosed until adulthood, when sensory, motor, bowel, and bladder control issues emerge. This delayed presentation of symptoms relates to the degree of strain on the spinal cord over time.

Tethering may also develop after spinal cord injury. 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 or feeling, or the onset of pain or autonomic nervous system symptoms.

In adults, onset of symptoms typically include:

- Severe pain (in the lower back and radiating into the legs, groin, and perineum)

- Bilateral muscle weakness and numbness

- Loss of feeling and movement in lower extremities

- Urinary irregularities (incontinence or retention)

- Bowel control issues

Neurological symptoms can include a mixed picture of upper and lower motor neuron findings, such as amyotrophy, hyperreflexia, and pathologic plantar response, occurring in the same limb. Profound sensory changes, such as loss of pain, temperature, and proprioceptive sensations, are common. Last, progressive symptoms of a neuropathic bladder are noted on over 70% of adult patients, versus only 20% to 30% of children. These symptoms include urinary frequency and urgency, feeling of incomplete voiding, poor voluntary control, and urge and stress incontinence. Chronic recurrent infections are common and occasionally lead to nephrolithiasis (kidney stones), renal failure, or renal transplantation. Female patients also give a history of ineffective labor and postpartum rectal prolapse, presumably due to an atonic pelvic floor.

In contrast to STD, the subtype spondylocostal dysostosis, or SCD features intrinsic rib anomalies, in addition to vertebral anomalies. Intrinsic rib anomalies include defects such as birfurcation, broadening and fusion that are not directly related to the vertebral anomalies (such as in STD, where extensive posterior rib fusion occurs due to segmentation defects and extreme shortening of the thoracic vertebral column). In both subtypes, the pulmonary restriction may result in pulmonary hypertension, and have other potential cardiac implications.

Clinodactyly (from the Ancient Greek κλίνειν ' meaning "to bend" and δάκτυλος ' meaning "digit") is a medical term describing the curvature of a digit (a finger or toe) in the plane of the palm, most commonly the fifth finger (the "little finger") towards the adjacent fourth finger (the "ring finger").

It is a fairly common isolated anomaly which often goes unnoticed, but also occurs in combination with other abnormalities in certain genetic syndromes.

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.

Spondylothoracic dysplasia, or STD, has been repeatedly described as an autosomal recessively inherited condition that results in a characteristic fan-like configuration of the ribs with minimal intrinsic rib anomalies. Infants born with this condition typically died early in life due to recurrent respiratory infections and pneumonia due to their restricted thorax. Recently, a report has documented that actual mortality associated with STD is only about 50%, with many survivors leading healthy, independent lives.

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.

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.

Tethered spinal cord can be caused by various conditions but the main cause is when tissue attachments limit the movement of the spinal cord in the spinal column which causes abnormal stretching of the cord. The tethered spinal cord syndrome is correlated with having the causes:

- Spina bifida

- Occulta

- Mylomeningocele

- Meningocele

- History of spinal trauma

- History of spinal surgery

- Tumor(s) in the spinal column

- Thickened and/or tight filum terminale

- Lipoma(s) in the spinal column

- Dermal Sinus Tract (congenital deformity)

- Diastematomyelia (split spinal cord)

Tethered spinal cord is a disorder and not a mechanism so it does not spread to other people and there are no measures that can be done to prevent it beforehand. The only preventative measure that is successful is to surgically untether the spinal cord though there might already be irreversible damage.

Wobbler disease is a catchall term referring to several possible malformations of the cervical vertebrae that cause an unsteady (wobbly) gait and weakness in dogs and horses. A number of different conditions of the cervical (neck) spinal column cause similar clinical signs. These conditions may include malformation of the vertebrae, intervertebral disc protrusion, and disease of the interspinal ligaments, ligamenta flava, and articular facets of the vertebrae. Wobbler disease is also known as cervical vertebral instability, cervical spondylomyelopathy (CSM), and cervical vertebral malformation (CVM). In dogs, the disease is most common in large breeds, especially Great Danes and Doberman Pinschers. In horses, it is not linked to a particular breed, though it is most often seen in tall, race-bred horses of Thoroughbred or Standardbred ancestry. It is most likely inherited to at least some extent in dogs and horses.

Kyphosis (from Greek κυφός "kyphos", a hump) is an abnormally excessive convex "kyphotic" curvature of the spine as it occurs in the cervical, thoracic and sacral regions. (Abnormal inward concave "lordotic" curving of the cervical and lumbar regions of the spine is called lordosis.) Kyphosis can be called roundback or Kelso's hunchback. It can result from degenerative diseases such as arthritis; developmental problems, most commonly Scheuermann's disease; osteoporosis with compression fractures of the vertebra; multiple myeloma or trauma. A normal thoracic spine extends from the 1st to the 12th vertebra and should have a slight kyphotic angle, ranging from 20° to 45°. When the "roundness" of the upper spine increases past 45° it is called kyphosis or "hyperkyphosis". Scheuermann's kyphosis is the most classic form of hyperkyphosis and is the result of wedged vertebrae that develop during adolescence. The cause is not currently known and the condition appears to be multifactorial and is seen more frequently in males than females.

In the sense of a deformity, it is the pathological curving of the spine, where parts of the spinal column lose some or all of their lordotic profile. This causes a bowing of the back, seen as a slouching posture.

While most cases of kyphosis are mild and only require routine monitoring, serious cases can be debilitating. High degrees of kyphosis can cause severe pain and discomfort, breathing and digestion difficulties, cardiovascular irregularities, neurological compromise and, in the more severe cases, significantly shortened life spans. These types of high-end curves typically do not respond well to conservative treatment and almost always warrant spinal fusion surgery, which can restore the body's natural degree of curvature.

Degenerative disc disease can result in lower back or upper neck pain, but this isn't always true across the board. In fact, the amount of degeneration does not correlate well with the amount of pain patients experience. Many people experience no pain while others, with exactly the same amount of damage have severe, chronic pain. Whether a patient experiences pain or not largely depends on the location of the affected disc and the amount of pressure that is being put on the spinal column and surrounding nerve roots.

Nevertheless, degenerative disc disease is one of the most common sources of back pain and affects approximately 30 million people every year. With symptomatic degenerative disc disease, the pain can vary depending on the location of the affected disc. A degenerated disc in the lower back can result in lower back pain, sometimes radiating to the hips, as well as pain in the buttocks, thighs or legs. If pressure is being placed on the nerves by exposed nucleus pulposus, sporadic tingling or weakness through the knees and legs can also occur.

A degenerated disc in the upper neck will often result in pain to the neck, arm, shoulders and hands; tingling in the fingers may also be evident if nerve impingement is occurring.

Pain is most commonly felt or worsened by movements such as sitting, bending, lifting and twisting.

After an injury, some discs become painful because of inflammation and the pain comes and goes. Some people have nerve endings that penetrate more deeply into the anulus fibrosus (outer layer of the disc) than others, making discs more likely to generate pain. In the alternative, the healing of trauma to the outer anulus fibrosus may result in the innervation of the scar tissue and pain impulses from the disc, as these nerves become inflamed by nucleus pulposus material. Degenerative disc disease can lead to a chronic debilitating condition and can have a serious negative impact on a person's quality of life. When pain from degenerative disc disease is severe, traditional nonoperative treatment may be ineffective.

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.

Scheuermann's disease is considered to be a form of juvenile osteochondrosis of the spine. It is found mostly in teenagers and presents a significantly worse deformity than postural kyphosis. Patients suffering with Scheuermann’s kyphosis cannot consciously correct their posture. The apex of their curve, located in the thoracic vertebrae, is quite rigid.

Scheuermann's disease is notorious for causing lower and mid-level back and neck pain, which can be severe and disabling. The sufferer may feel pain at the apex of the curve, which is aggravated by physical activity and by periods of standing or sitting; this can have a significantly detrimental effect to their lives as their level of activity is curbed by their disability. The sufferer may feel isolated or uneasy amongst their peers if they are children, depending on the level of deformity.

In addition to the pain associated with Scheuermann's disease, many sufferers of the disorder have loss of vertebral height, and depending on where the apex of the curve is, may have a visual 'hunchback' or 'roundback'. It has been reported that curves in the lower thoracic region cause more pain, whereas curves in the upper region present a more visual deformity. Nevertheless, it is typically pain or cosmetic reasons that prompt sufferers to seek help for their condition. In studies, kyphosis is better characterized for the thoracic spine than for the lumbar spine.

The seventh and tenth thoracic vertebrae are most commonly affected. It causes backache and spinal curvature. In very serious cases it may cause internal problems and spinal cord damage, but these cases are extremely rare. The curvature of the back decreases height, thus putting pressure on internal organs, wearing them out more quickly than the natural aging process; surgical procedures are almost always recommended in this case.

Lumbar hyperlordosis is a condition that occurs when the lumbar region (lower back) experiences stress or extra weight and is arched to point of muscle pain or spasms. Lumbar hyperlordosis is a common postural position where the natural curve of the lumbar region of the back is slightly or dramatically accentuated. Commonly known as swayback, it is common in dancers. Imbalances in muscle strength and length are also a cause, such as weak hamstrings, or tight hip flexors (psoas). A major feature of lumbar hyperlordosis is a forward pelvic tilt, resulting in the pelvis resting on top of the thighs.

Other health conditions and disorders can cause hyperlordosis. Achondroplasia (a disorder where bones grow abnormally which can result in short stature as in dwarfism), Spondylolisthesis (a condition in which vertebrae slip forward) and osteoporosis (the most common bone disease in which bone density is lost resulting in bone weakness and increased likelihood of fracture) are some of the most common causes of hyperlordosis. Other causes include obesity, hyperkyphosis (spine curvature disorder in which the thoracic curvature is abnormally rounded), discitits (an inflammation of the intervertebral disc space caused by infection) and benign juvenile lordosis. Other factors may also include those with rare diseases, as is the case with Ehlers Danlos Syndrome (EDS), where hyper-extensive and usually unstable joints (e.g. joints that are problematically much more flexible, frequently to the point of partial or full dislocation) are quite common throughout the body. With such hyper-extensibility, it is also quite common (if not the norm) to find the muscles surrounding the joints to be a major source of compensation when such instability exists.

Excessive lordotic curvature – lumbar hyperlordosis, is also called hollow back, and saddle back (after a similar condition that affects some horses); swayback usually refers to a nearly opposite postural misalignment that can initially look quite similar. Common causes of lumbar hyperlordosis include tight low back muscles, excessive visceral fat, and pregnancy. Rickets, a vitamin D deficiency in children, can cause lumbar lordosis.

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.