Bone mineral density decreases with increasing age. Osteoporotic bone loss can be prevented through an adequate intake of vitamin C and vitamin D, coupled with exercise and by being a non-smoker. A study by Cheng et al. in 1997, showed that greater bone density indicated less risk for fractures in the calcaneus.

The exact cause is unknown. Mechanical factors, dietary and long term use of some antidepressants may be of significance. There is a correlation between these factors but not a cause or effect. The distinctive radiological feature of DISH is the continuous linear calcification along the antero-medial aspect of the thoracic spine. The disease is usually found in people in their 60s and above, and is extremely rare in people in their 40s and 30s. The disease can spread to any joint of the body, affecting the neck, shoulders, ribs, hips, pelvis, knees, ankles, and hands. The disease is not fatal, however some associated complications can lead to death. Complications include paralysis, dysphagia (the inability to swallow), and pulmonary infections. Although DISH manifests in a similar manner to ankylosing spondylitis, these two are totally separate diseases. Ankylosing spondylitis is a genetic disease with identifiable marks, and affects organs. DISH has no indication of a genetic link, and does not affect organs other than the lungs, which is only indirect due to the fusion of the rib cage.

Long term treatment of acne with vitamin derived retinoids, such as etretinate and acitretin, have been associated with "extraspinal" hyperostosis.

After adolescence, some men and women use bodybuilding as a means to hide their malformation. Some women find that their breasts, if large enough, serve the same purpose. Some plastic surgeons perform breast augmentation to disguise mild to moderate cases in women. Bodybuilding is suggested for people with symmetrical pectus carinatum.

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.

Till date about 18 cases of Spondylocostal dysostosis have been reported in literature.

Many vertebrates, especially reptiles, have cervical ribs as a normal part of their anatomy rather than a pathological condition. Some sauropods had exceptionally long cervical ribs; those of "Mamenchisaurus hochuanensis" were nearly 4 meters long.

In birds, the cervical ribs are small and completely fused to the vertebrae.

In mammals the ventral parts of the transverse processes of the cervical vertebrae are the fused-on cervical ribs.

Recent studies have also found a high percent of cervical ribs in woolly mammoths. It is believed that the decline in mammoth numbers may have forced inbreeding within the species which in turn has increased the number of mammoths being born with cervical ribs. Cervical ribs have been connected with leukaemia in human children, so it has given scientists new evidence to believe that the mammoth's extinction was attributed to the condition.

Pectus malformations are common; about 1 in 400 people have a pectus disorder.

Pectus carinatum is rarer than pectus excavatum, another pectus disorder, occurring in only about 20% of people with pectus malformations. About four out of five patients are males.

Presence at birth is extremely rare and associated with other congenital anomalies such as proximal femoral focal deficiency, fibular hemimelia or anomalies in other part of the body such as cleidocranial dyastosis. The femoral deformity is present in the subtrochantric area where the bone is bent. The cortices are thickened and may be associated with overlying skin dimples. External rotation of the femur with valgus deformity of knee may be noted. This condition does not resolve and requires surgical management. Surgical management includes valgus osteotomy to improve hip biomechanics and length and rotational osteotomy to correct retroversion and lengthening.

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%). 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.

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.

In 1968, Dr. David Rimoin and colleagues in Baltimore first distinguished between the two major presentations of Jarcho-Levin. Both conditions were characterized as failures of proper vertebral segmentation. However, the condition within the family described in their article appeared to be inherited in an autosomal dominant fashion and had a less severe course than that reported by other investigators. They specified their condition as spondylocostal dysplasia, which has since become known as spondylocostal dysostosis. The subtype of Jarcho-Levin with which they contrasted their reported cases to is now known as spondylothoracic dysplasia.

Coxa vara is a deformity of the hip, whereby the angle between the head and the shaft of the femur is reduced to less than 120 degrees. This results in the leg being shortened, and the development of a limp. It is commonly caused by injury, such as a fracture. It can also occur when the bone tissue in the neck of the femur is softer than normal, causing it to bend under the weight of the body. This may either be congenital or the result of a bone disorder. The most common cause of coxa vara is either congenital or developmental. Other common causes include metabolic bone diseases (e.g. Paget's disease of bone), post-Perthes deformity, osteomyelitis, and post traumatic (due to improper healing of a fracture between the greater and lesser trochanter). Shepherd's Crook deformity is a severe form of coxa vara where the proximal femur is severely deformed with a reduction in the neck shaft angle beyond 90 degrees. It is most commonly a sequela of osteogenesis imperfecta, Pagets disease, osteomyelitis, tumour and tumour-like conditions (e.g. fibrous dysplasia).

Coxa vara can happen in cleidocranial dysostosis.

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.

Calcaneal fractures are often attributed to shearing stress adjoined with compressive forces combined with a rotary direction (Soeur, 1975). These forces are typically linked to injuries in which an individual falls from a height, involvement in an automobile accident, or muscular stress where the resulting forces can lead to the trauma of fracture. Overlooked aspects of what can lead to a calcaneal fracture are the roles of osteoporosis and diabetes.

Unfortunately, the prevention of falls and automobile accidents is limited and applies to unique circumstances that should be avoided. The risk of muscular stress fractures can be reduced through stretching and weight-bearing exercise, such as strength training. In addition, footwear can influence forces that may cause a calcaneal fracture and can prevent them as well. A 2012 study conducted by Salzler showed that the increasing trend toward minimalist footwear or running barefoot can lead to a variety of stress fractures including that of the calcaneus.

Pectus excavatum occurs in an estimated 1 in 150 to 1 in 1000 births, with male predominance (male-to-female ratio of 3:1). In 35% to 45% of cases family members are affected.

Researchers are unsure of the cause of pectus excavatum but assume that there is a genetic component for at least some of the cases as 37% of individuals have an affected first degree family member. As of 2012, a number of genetic markers for pectus excavatum have also been discovered.

Pectus excavatum is a relatively common symptom of Noonan syndrome, Marfan syndrome and Loeys-Dietz syndrome and sometimes is found in other connective tissue disorders such as Ehlers–Danlos Syndrome. Many children with spinal muscular atrophy develop pectus excavatum due to their diaphragmatic breathing. Pectus excavatum also occurs in about 1% of persons diagnosed with celiac disease for unknown reasons.

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.

A cervical rib in humans is an extra rib which arises from the seventh cervical vertebra. Sometimes known as "neck ribs", their presence is a congenital abnormality located above the normal first rib. A cervical rib is estimated to occur in 0.2% (1 in 500 people) to 0.5% of the population. People may have a cervical rib on the right, left or both sides.

Most cases of cervical ribs are not clinically relevant and do not have symptoms; cervical ribs are generally discovered incidentally. However, they vary widely in size and shape, and in rare cases, they may cause problems such as contributing to thoracic outlet syndrome, because of pressure on the nerves that may be caused by the presence of the rib.

A cervical rib represents a persistent ossification of the C7 lateral costal element. During early development, this ossified costal element typically becomes re-absorbed. Failure of this process results in a variably elongated transverse process or complete rib that can be anteriorly fused with the T1 first rib below.

On imaging, cervical ribs can be distinguished because their transverse processes are directed inferolaterally, whereas those of the adjacent thoracic spine are directed anterolaterally.

Diffuse idiopathic skeletal hyperostosis (DISH) is a non-inflammatory spondyloarthropathy which predominantly affects the spine. It is characterized by ankylosis and enthesopathy (ossification of the ligaments and entheses). It most commonly affects the thoracic and thoraco-lumbar spine, but involvement is variable and can include the entire spine.

A flexion teardrop fracture is a fracture of the anteroinferior aspect of a cervical vertebral body due to flexion of the spine along with vertical axial compression. A teardrop fracture is usually associated with a spinal cord injury, often a result of displacement of the posterior portion of the vertebral body into the spinal canal.

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.

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.

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.

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.

Several studies have reported that life expectancy appears to be normal for people with CCD.

Cleidocranial dysostosis (CCD), also called cleidocranial dysplasia, is a birth defect that mostly affects the bones and teeth. The collarbones are typically either poorly developed or absent, which allows the shoulders to be brought close together. The front of the skull often does not close until later, and those affected are often shorter than average. Other symptoms may include a prominent forehead, wide set eyes, abnormal teeth, and a flat nose. Symptoms vary among people; however, intelligence is typically normal.

The condition is either inherited from a person's parents or occurs as a new mutation. It is inherited in an autosomal dominant manner. It is due to a defect in the RUNX2 gene which is involved in bone formation. Diagnosis is suspected based on symptoms and X-rays with confirmation by genetic testing. Other conditions that can produce similar symptoms include mandibuloacral dysplasia, pyknodysostosis, osteogenesis imperfecta, and Hajdu-Cheney syndrome.

Treatment includes supportive measures such as a device to protect the skull and dental care. Surgery may be performed to fix certain bone abnormalities. Life expectancy is generally normal.

It affects about one per million people. Males and females are equally commonly affected. Modern descriptions of the condition date to at least 1896. The term is from "cleido" meaning collarbone, "cranial" meaning head, and "dysostosis" meaning formation of abnormal bone.

Radioulnar synostosis is one of the more common failures of separation of parts of the upper limb. There are two general types: one is characterized by fusion of the radius and ulna at their proximal borders and the other is fused distal to the proximal radial epiphysis. Most cases are sporadic, congenital (due to a defect in longitudinal segmentation at the 7th week of development) and less often post-traumatic, bilateral in 60%, and more common in males. Familial cases in association with autosomal dominant transmission appear to be concentrated in certain geographic regions, such as Sicily.

The condition frequently is not noted until late childhood, as function may be normal, especially in unilateral cases. Increased wrist motion may compensate for the absent forearm motion. It has been suggested that individuals whose forearms are fixed in greater amounts of pronation (over 60 degrees) face more problems with function than those with around 20 degrees of fixation. Pain is generally not a problem, unless radial head dislocation should occur.

Most examples of radioulnar synostosis are isolated (non-syndromic). Syndromes that may be accompanied by radioulnar synostosis include X chromosome polyploidy (e.g., XXXY) and other chromosome disorders (e.g., 4p- syndrome, Williams syndrome), acrofacial dysostosis, Antley–Bixler syndrome, genitopatellar syndrome, Greig cephalopolysyndactyly syndrome, hereditary multiple osteochondromas (hereditary multiple exostoses), limb-body wall complex, and Nievergelt syndrome.

Craniosynostosis (from cranio, cranium; + syn, together; + ostosis relating to bone) is a condition in which one or more of the fibrous sutures in an infant skull prematurely fuses by turning into bone (ossification). Craniosynostosis has following kinds: scaphocephaly, trigonocephaly, plagiocephaly, anterior plagiocephaly, posterior plagiocephaly, brachycephaly, oxycephaly, pansynostosis.