Renal osteodystrophy may exhibit no symptoms; if it does show symptoms, they include:

- Bone pain

- Joint pain

- Bone deformation

- Bone fracture

- The broader concept of chronic kidney disease-mineral and bone disorder (CKD-MBD) is not only associated with fractures but also with cardiovascular calcification, poor quality of life and increased morbidity and mortality in CKD patients (the so-called bone-vascular axis). These clinical consequences are acquiring such an importance that scientific working groups (such as the ERA-EDTA CKD-MBD Working Group) or international initiatives are trying to promote research in the field including basic, translational and clinical research.

In osteochondritis dissecans, fragments of cartilage or bone become loose within a joint, leading to pain and inflammation. These fragments are sometimes referred to as joint mice. OCD is a type of osteochondrosis in which a lesion has formed within the cartilage layer itself, giving rise to secondary inflammation. OCD most commonly affects the knee, although it can affect other joints such as the ankle or the elbow.

People with OCD report activity-related pain that develops gradually. Individual complaints usually consist of mechanical symptoms including pain, swelling, catching, locking, popping noises, and buckling / giving way; the primary presenting symptom may be a restriction in the range of movement. Symptoms typically present within the initial weeks of stage I; however, the onset of stage II occurs within months and offers little time for diagnosis. The disease progresses rapidly beyond stage II, as OCD lesions quickly move from stable cysts or fissures to unstable fragments. Non-specific symptoms, caused by similar injuries such as sprains and strains, can delay a definitive diagnosis.

Physical examination typically reveals fluid in the joint, tenderness, and crepitus. The tenderness may initially spread, but often reverts to a well-defined focal point as the lesion progresses. Just as OCD shares symptoms with common maladies, acute osteochondral fracture has a similar presentation with tenderness in the affected joint, but is usually associated with a fatty hemarthrosis. Although there is no significant pathologic gait or characteristic alignment abnormality associated with OCD, the patient may walk with the involved leg externally rotated in an attempt to avoid tibial spine impingement on the lateral aspect of the medial condyle of the femur.

Because collagen plays an important role in the development of the body, people with Kniest Dysplasia will typically have their first symptoms at birth. These symptoms can include:.

- Musculoskeletal Problems

- Short limbs

- Shortened body trunk

- Flattened bones in the spine

- kyphoscoliosis

- Scoliosis (Lateral curvature of the spine)

- Early development of arthritis

- Respiratory problems

- Respiratory tract infection

- Difficulty breathing

- Eye problems

- Severe myopia (near-sightedness)

- Cataract (cloudiness in the lens of the eye)

- Hearing problems

- progressive hearing loss

- ear infections

Most symptoms are chronic and will continue to worsen as the individual ages. It is essential to have regular checkups with general doctors, orthopedist, ophthalmologists, and/or otorhinolaryngologists. This will help to detect whether there are any changes that could cause concern.

To diagnose osteochondritis dissecans, an X-ray, CT scan or MRI scan can be performed to show necrosis of subchondral bone, formation of loose fragments, or both. Occasionally a nuclear medicine bone scan is used to assess the degree of loosening within the joint.

Renal osteodystrophy is currently defined as an alteration of bone morphology in patients with chronic kidney disease (CKD). It is one measure of the skeletal component of the systemic disorder of chronic kidney disease-mineral and bone disorder (CKD-MBD). The term "renal osteodystrophy" was coined in 1943, 60 years after an association was identified between bone disease and renal failure. The traditional types of renal osteodystrophy have been defined on the basis of turnover and mineralization as follows: mild, slight increase in turnover and normal mineralization; osteitis fibrosa, increased turnover and normal mineralization; osteomalacia, decreased turnover and abnormal mineralization; adynamic, decreased turnover and acellularity; mixed, increased turnover with abnormal mineralization. A Kidney Disease: Improving Global Outcomes report has suggested that bone biopsies in patients with CKD should be characterized by determining bone turnover, mineralization, and volume (TMV system). On the other hand, CKD-MBD is defined as a systemic disorder of mineral and bone metabolism due to CKD manifested by either one or a combination of the following: 1) abnormalities of calcium, phosphorus, PTH, or vitamin D metabolism; 2) abnormalities in bone turnover, mineralization, volume, linear growth, or strength (renal osteodystrophy); and 3) vascular or other soft-tissue calcification.

Kniest Dysplasia is a rare form of dwarfism caused by a mutation in the COL2A1 gene on chromosome 12. The COL2A1 gene is responsible for producing type II collagen. The mutation of COL2A1 gene leads to abnormal skeletal growth and problems with hearing and vision. What characterizes kniest dysplasia from other type II Osteochondrodysplasia is the level of severity and the dumb-bell shape of shortened long tubular bones. This condition was first diagnosed by Dr. Wilhelm Kniest in 1952. Dr. Kniest noticed that his 50 year old patient was having difficulties with restricted joint mobility. The patient had a short stature and was also suffering from blindness. Upon analysis of the patient's DNA, Dr. Kniest discovered that a mutation had occurred at a splice site of the COL2A1 gene. This condition is very rare and occurs less than 1 in 1,000,000 people. Males and females have equal chances of having this condition. Currently, there is no cure for kniest dysplasia. Alternative names for Kniest Dysplasia can include Kniest Syndrome, Swiss Cheese Cartilage Syndrome, Kniest Chondrodystrophy, or Metatrophic Dwarfism Type II.

An individual with Panner disease most commonly experiences elbow pain near the capitellum. Other symptoms include:

- Stiffness in the elbow

- Elbow swelling

- Limited range of motion

- Elbow extension limitation

- Tenderness

These symptoms worsen with physical activity such a throwing a ball or gymnastics for example. The symptoms begin unexpectedly and are often present for several days or weeks, and the symptoms tend to last even longer.

Panner disease is an osteochondrosis of the capitellum of the elbow. Panner disease is primarily seen in boys between the ages of five and ten years old. Panner disease is often caused by excessive throwing due to valgus stress. The disease causes pain and stiffness in the affected elbow and may limit extension; the affected elbow is usually on the dominant arm the child uses. The disease may be associated with pitching and athletic activity. On radiographs, the capitellum may appear irregular with areas of radiolucency. Treatment is symptomatic, with a good prognosis. Treatment is minimal and includes restricting athletic activity to allow for the elbow to heal and for pain to be relieved. The disease is named after the Danish radiologist Hans Jessen Panner (1871–1930).

Hair abnormalities are very prominent in majority of the cases of TDO. Kinky/curly hair that is unusually dry and easily sheds is present at birth. In 80% of cases, the hair has a more relaxed appearance by adolescence. The presence of this hair texture type is a defining characteristic between a diagnosis of TDO verses amelogenesis imperfecta with hypomaturation. Additionally, in TDO the nails are usually abnormally thin, brittle, and split frequently. Cranial deficiencies are marked by the presence of having a long skull relative to its width, or protrusive foreheads due to increased thickness of the cranial bones and premature closing of the associated sutures in the skull. The long bones in the body (arms, legs) are also abnormally long and tend to fracture very easily. Osteosclerosis, commonly seen in TDO cases is characterized by an increase in bone density, affecting the skull and the mastoid process located behind the jawbone on the skull, as well as a shortened ramus seen in people with TDO. There are no known pathological problems associated with hair and bone changes in people with this disease. Changes in the long bones tend to appear later in development, but changes in the teeth appear once the teeth being to form, called primary dentition. The hair and bone abnormalities are evaluated radiographically during initial diagnosis, and visually during the course of the disease. Radiographic exams may be repeated if there is suspect of fracture.

A bone cyst or geode is a cyst that forms in bone.

Types include:

- Unicameral bone cyst

- Aneurysmal bone cyst

- Traumatic bone cyst

Ringbone usually occurs in the front legs but can also be in the hind legs, and is usually worse in one leg than the other. Ringbone is most often found in mature horses, especially those in intensive training.

High ringbone: The horse will have a bony growth around the pastern area, and the pastern will have less mobility. The horse will show pain when the pastern joint is moved or rotated. Early cases will have a lameness score of 1-2 out of 5, with little or no bony swelling seen, although possibly felt when compared to the opposite pastern. Lameness will worsen to a grade 2-3 on a scale of 5 as the ringbone worsens.

Low ringbone: The horse will have moderate lameness (grade 2-3), even in early cases, because of the closeness of the ringbone to the other structures in the hoof. When severe or very advanced, the bony growth will be able to be seen on the coronet.

Ringbone is exostosis (bone growth) in the pastern or coffin joint of a horse. In severe cases, the growth can encircle the bones, giving ringbone its name. It has been suggested by some authors that such a colloquial term, whilst commonly used, might be misleading and that it would be better to refer to this condition as osteoarthritis of the inter-phalangeal joints in ungulates (Rogers and Waldron, 1995: 34-35).

Ringbone can be classified by its location, with "high ringbone" occurring on the lower part of the large pastern bone or the upper part of the small pastern bone. "Low ringbone" occurs on the lower part of the small pastern bone or the upper part of the coffin bone. High ringbone is easier seen than low ringbone, as low ringbone occurs in the hoof of the horse. However, low ringbone may be seen if it becomes serious, as it creates a bony bump on the coronet of the horse.

By far, the two most common symptoms described are pain and the feeling that teeth no longer correctly meet (traumatic malocclusion, or disocclusion). The teeth are very sensitive to pressure (proprioception), so even a small change in the location of the teeth will generate this sensation. People will also be very sensitive to touching the area of the jaw that is broken, or in the case of condylar fracture the area just in front of the tragus of the ear.

Other symptoms may include loose teeth (teeth on either side of the fracture will feel loose because the fracture is mobile), numbness (because the inferior alveolar nerve runs along the jaw and can be compressed by a fracture) and trismus (difficulty opening the mouth).

Outside the mouth, signs of swelling, bruising and deformity can all be seen. Condylar fractures are deep, so it is rare to see significant swelling although, the trauma can cause fracture of the bone on the anterior aspect of the external auditory meatus so bruising or bleeding can sometimes be seen in the ear canal. Mouth opening can be diminished (less than 3 cm). There can be numbness or altered sensation (anesthesia/paraesthesia in the chin and lower lip (the distribution of the mental nerve).

Intraorally, if the fracture occurs in the tooth bearing area, a step may seen between the teeth on either side of the fracture or a space can be seen (often mistaken for a lost tooth) and bleeding from the gingiva in the area. There can be an open bite where the lower teeth, no longer meet the upper teeth. In the case of a unilateral condylar fracture the back teeth on the side of the fracture will meet and the open bite will get progressively greater towards the other side of the mouth.

Sometimes bruising will develop in the floor of the mouth (sublingual eccymosis) and the fracture can be moved by moving either side of the fracture segment up and down. For fractures that occur in the non-tooth bearing area (condyle, ramus, and sometimes the angle) an open bite is an important clinical feature since little else, other than swelling, may be apparent.

This type of fractured mandible can involve one condyle (unilateral) or both (bilateral). Unilateral condylar fracture may cause restricted and painful jaw movement. There may be swelling over the temporomandibular joint region and bleeding from the ear because of lacerations to the external auditory meatus. The hematoma may spread downwards and backwards behind the ear, which may be confused with Battle's sign (a sign of a base of skull fracture), although this is an uncommon finding so if present, intra-cranial injury must be ruled out. If the bones fracture and overlie each other there may be shortening of the height of the ramus. This results in gagging of the teeth on the fractured side (the teeth meet too soon on the fractured side, and not on the non fractured side, i.e. "open bite" that becomes progressively worse to the unaffected side). When the mouth is opened, there may be deviation of the mandible towards the fractured side. Bilateral condylar fractures may cause the above signs and symptoms, but on both sides. Malocclusion and restricted jaw movement are usually more severe. Bilateral body or parasymphysis fractures are sometimes termed "flail mandible", and can cause involuntary posterior movement of the tongue with subsequent obstruction of the upper airway. Displacement of the condyle through the roof of glenoid fossa and into the middle cranial fossa is rare. Bilateral condylar fractures combined with a symphyseal fracture is sometimes termed a guardsman's fracture. The name comes from this injury occurring in soldiers who faint on parade grounds and strike the floor with their chin.

On CT scans, bone cysts that have a radiodensity of 20 Hounsfield units (HU) or less, and are osteolytic, tend to be aneurysmal bone cysts.

In contrast, intraosseous lipomas have a lower radiodensity of -40 to -60 HU.

In the oral cavity 100% of people diagnosed with TDO have taurodontism which is characterized by vertically enlarged pulp chambers at the expense of the roots of the teeth; the floor of the pulp chamber and furcation is moved apically down. This is due to the failure of the Hertwig epithelial root sheath which maps the shape of the forming tooth roots during active differentiation. Amelogenesis imperfecta, an abnormal formation of the enamel or external layer of the crown of the tooth, may also be present where the tooth enamel may be thin or absent. There are several clinical subsets of amelogenesis imperfecta, but common to TDO is the hypoplastic-hypomaturation subtype; the hypomaturation-hypoplastic is less common in individuals with TDO. The difference between the 2 dominant subtypes is the changes seen in the enamel matrix, and the phenotypic type that predominates. The hypoplastic-hypomaturation type of amelogenesis imperfecta with TDO occurs where the tooth enamel depicts a generalized pitted pattern, with open contacts between the teeth as well as an open bite. A smaller amount of cases are of the hypomaturation-hypoplastic case type, in which the enamel structure is softer due to the under maturation of ameloblasts during development. Mandibular prognathism also called a severe underbite, is also a prominent feature in TDO. Prognathism defects are diagnosed based the level of severity that this condition interferes with being able to chew or speak properly.

Due to improper tooth development, TDO patients suffer from high rates of dental caries causing dental abscess. The under maturation of the enamel causes the tooth structure to be softer, and more susceptible to the effects of bruxism due to abnormalities in skeletal development. The oral abnormalities are evaluated by radiographs and visual examination. Oral radiographs are frequently repeated due to the high incidence of infection due to abnormal biting patterns seen in TDO cases.

The neuromuscular symptoms of hypocalcemia are caused by a positive bathmotropic effect due to the decreased interaction of calcium with sodium channels. Since calcium blocks sodium channels and inhibits depolarization of nerve and muscle fibers,reduced calcium lowers the threshold for depolarization. The symptoms can be recalled by the mnemonic "CATs go numb" - convulsions, arrhythmias, tetany, and numbness in the hands and feet and around the mouth.

One of the principle symptoms of GAPO syndrome is growth retardation, caused by slow skeletal formation and results in individuals being below average height. Alopecia, or hair loss, is another key indication of GAPO syndrome. Their hair is typically thinly dispersed, and fragile, which often leads to baldness later in life. Similarly, tooth growth is stunted, with teeth failing to emerge form the gums or otherwise develop normally. Atrophy of the optic nerve occurs in approximately one third of individuals. This degradation leads to inhibited peripheral vision, and increased difficulty distinguishing colours.

While not a defining feature, most sufferers of GAPO syndrome have coarse facial features, and abnormal structure of the middle portion of their faces, typically coupled with a large forehead. Individuals with the disease tend to have depressed nose bridges, protruding ears, and abnormally thick lips, though these symptoms are not unique to this disorder.

No direct correlation has been found between GAPO syndrome and mental retardation, though cases of individuals having both have been reported.

Due to the severity of the phenotype, GAPO syndrome can be diagnosed very early on. Most cases can be diagnosed by 6 months of age, and most symptoms will be apparent by age 2.

Hypocalcaemia, also spelled hypocalcemia, is low calcium levels in the blood serum. The normal range is 2.1–2.6 mmol/L (8.8–10.7 mg/dL, 4.3–5.2 mEq/L) with levels less than 2.1 mmol/L defined as hypocalcemia. Mildly low levels that develop slowly often have no symptoms. Otherwise symptoms may include numbness, muscle spasms, seizures, confusion, or cardiac arrest.

Common causes include hypoparathyroidism and vitamin D deficiency. Others causes include kidney failure, pancreatitis, calcium channel blocker overdose, rhabdomyolysis, tumor lysis syndrome, and medications such as bisphosphonates. Diagnosis should generally be confirmed with a corrected calcium or ionized calcium level. Specific changes may be seen on an electrocardiogram (ECG).

Initial treatment for severe disease is with intravenous calcium chloride and possibly magnesium sulfate. Other treatments may include vitamin D, magnesium, and calcium supplements. If due to hypoparathyroidism, hydrochlorothiazide, phosphate binders, and a low salt diet may also be recommended. About 18% of people who are in hospital have hypocalcemia.

The mucopolysaccharidoses share many clinical features but have varying degrees of severity. These features may not be apparent at birth but progress as storage of glycosaminoglycans affects bone, skeletal structure, connective tissues, and organs. Neurological complications may include damage to neurons (which send and receive signals throughout the body) as well as pain and impaired motor function. This results from compression of nerves or nerve roots in the spinal cord or in the peripheral nervous system, the part of the nervous system that connects the brain and spinal cord to sensory organs such as the eyes and to other organs, muscles, and tissues throughout the body.

Depending on the mucopolysaccharidosis subtype, affected individuals may have normal intellect or have cognitive impairments, may experience developmental delay, or may have severe behavioral problems. Many individuals have hearing loss, either conductive (in which pressure behind the eardrum causes fluid from the lining of the middle ear to build up and eventually congeal), neurosensory (in which tiny hair cells in the inner ear are damaged), or both. Communicating hydrocephalus—in which the normal reabsorption of cerebrospinal fluid is blocked and causes increased pressure inside the head—is common in some of the mucopolysaccharidoses. Surgically inserting a shunt into the brain can drain fluid. The eye's cornea often becomes cloudy from intracellular storage, and glaucoma and degeneration of the retina also may affect the patient's vision.

Physical symptoms generally include coarse or rough facial features (including a flat nasal bridge, thick lips, and enlarged mouth and tongue), short stature with disproportionately short trunk (dwarfism), dysplasia (abnormal bone size and/or shape) and other skeletal irregularities, thickened skin, enlarged organs such as liver (hepatomegaly) or spleen (splenomegaly), hernias, and excessive body hair growth. Short and often claw-like hands, progressive joint stiffness, and carpal tunnel syndrome can restrict hand mobility and function. Recurring respiratory infections are common, as are obstructive airway disease and obstructive sleep apnea. Many affected individuals also have heart disease, often involving enlarged or diseased heart valves.

Another lysosomal storage disease often confused with the mucopolysaccharidoses is mucolipidosis. In this disorder, excessive amounts of fatty materials known as lipids (another principal component of living cells) are stored, in addition to sugars. Persons with mucolipidosis may share some of the clinical features associated with the mucopolysaccharidoses (certain facial features, bony structure abnormalities, and damage to the brain), and increased amounts of the enzymes needed to break down the lipids are found in the blood.

Mucopolysaccharidoses are a group of metabolic disorders caused by the absence or malfunctioning of lysosomal enzymes needed to break down molecules called glycosaminoglycans. These long chains of sugar carbohydrates occur within the cells that help build bone, cartilage, tendons, corneas, skin and connective tissue. Glycosaminoglycans (formerly called mucopolysaccharides) are also found in the fluids that lubricate joints.

Subjects with a mucopolysaccharidosis either do not produce enough of one of the eleven enzymes required to break down these sugar chains into simpler molecules, or they produce enzymes that do not work properly. Over time, these glycosaminoglycans collect in the cells, blood and connective tissues. The result is permanent, progressive cellular damage which affects appearance, physical abilities, organ and system functioning, and, in most cases, mental development.

The mucopolysaccharidoses are part of the lysosomal storage disease family, a group of more than 40 genetic disorders that result when the lysosome organelle in animal cells malfunctions. The lysosome can be thought of as the cell's recycling center because it processes unwanted material into other substances that the cell can utilize. Lysosomes break down this unwanted matter via enzymes, highly specialized proteins essential for survival. Lysosomal disorders like mucopolysaccharidosis are triggered when a particular enzyme exists in too small an amount or is missing altogether.

GAPO syndrome is a rare, autosomal recessive disorder that causes severe growth retardation, and has been observed fewer than 30 times before 2011. GAPO is an acronym that encompasses the predominant traits of the disorder: growth retardation, alopecia, pseudoanodontia (teeth failing to emerge from the gums), and worsening optic atrophy in some subjects. Other common symptoms include premature aging, large, prominent foreheads, and delayed bone aging. GAPO syndrome typically results in premature death around age 30-40, due to interstitial fibrosis and atherosclerosis.

Tibial plateau fractures typically presents with knee effusion, swelling of the knee soft tissues and inability to bear weight. The knee may be deformed due to displacement and/or fragmentation of the tibia which leads to loss of its normal structural appearance. Blood in the soft tissues and knee joint (hemarthrosis) may lead to bruising and a doughy feel of the knee joint. Due to the tibial plateau's proximity to important vascular (i.e. arteries, veins) and neurological (i.e. nerves such as peroneal and tibial) structures, injuries to these may occur upon fracture. A careful examination of the neurovascular systems is imperative. A serious complication of tibial plateau fractures is compartment syndrome in which swelling causes compression of the nerves and blood vessels inside the leg and may ultimately lead to necrosis or cell death of the leg tissues.

A supracondylar humerus fracture is a fracture of the distal humerus just above the elbow joint. The fracture is usually transverse or oblique and above the medial and lateral condyles and epicondyles. This fracture pattern is relatively rare in adults, but is the most common type of elbow fracture in children. In children, many of these fractures are non-displaced and can be treated with casting. Some are angulated or displaced and are best treated with surgery. In children, most of these fractures can be treated effectively with expectation for full recovery. Some of these injuries can be complicated by poor healing or by associated blood vessel or nerve injuries with serious complications.

Supracondylar humerus fractures typically result from a fall on to an outstretched arm, usually leading to a forced hyperextension of the elbow. Typically, this is an isolated injury to the elbow (no injuries elsewhere). Children with this injury present with pain and swelling about the elbow. Motion at the elbow and at the wrist make the pain worse. With mild or moderate fracture displacement, there may be deformity at the elbow.