Increased risk of developing knee and hip osteoarthritis was found in those who:

- work with manual handling (e.g. lifting)

- have physically demanding work

- walk at work

- have climbing tasks at work (e.g. climb stairs or ladders)

Increased risk of developing hip osteoarthritis over time was found among those who work in bent or twisted positions.

Increased risk of knee osteoarthritis was found in those who:

- work in a kneeling or squatting position

- experience heavy lifting in combination with a kneeling or squatting posture

- work standing up

A number of studies have shown that there is a greater prevalence of the disease among siblings and especially identical twins, indicating a hereditary basis. Although a single factor is not generally sufficient to cause the disease, about half of the variation in susceptibility has been assigned to genetic factors.

As early human ancestors evolved into bipeds, changes occurred in the pelvis, hip joint and spine which increased the risk of osteoarthritis. Additionally genetic variations that increase the risk were likely not selected against because usually problems only occur after reproductive success.

The development of osteoarthritis is correlated with a history of previous joint injury and with obesity, especially with respect to knees. Since the correlation with obesity has been observed not only for knees but also for non-weight bearing joints and the loss of body fat is more closely related to symptom relief than the loss of body weight, it has been suggested that there may be a metabolic link to body fat as opposed to just mechanical loading.

Changes in sex hormone levels may play a role in the development of osteoarthritis as it is more prevalent among post-menopausal women than among men of the same age. A study of mice found natural female hormones to be protective while injections of the male hormone dihydrotestosterone reduced protection.

Arthritis mutilans' parent condition psoriatic arthritis leaves people with a mortality risk 60% higher than the general population, with premature death causes mirroring those of the general population, cardiovascular issues being most common. Life expectancy for people with psoriatic arthritis is estimated to be reduced by approximately 3 years.

Paget's disease may be caused by a slow virus infection (i.e., paramyxoviridae) present for many years before symptoms appear. Associated viral infections include respiratory syncytial virus, canine distemper virus, and the measles virus. However, recent evidence has cast some doubt upon the measles association. Laboratory contamination may have played a role in past studies linking paramyxovirus (e.g. measles) to Paget's disease.

Multiple epiphyseal dysplasia (MED) encompasses a spectrum of skeletal disorders, most of which are inherited in an autosomal dominant form. However, there is an autosomal recessive form.

Associated genes include COL9A1, COL9A2, COL9A3, COMP, and MATN3.

Types include:

Pagets disease of bone is the second most common metabolic bone disorder, after osteoporosis. The overall prevalence and severity of Paget's disease are decreasing; the cause for these changes is unclear. Paget's disease is rare in people less than 55 years of age, and the prevalence increases with age. Evidence from studies of autopsy results have demonstrated Paget's disease in about 3 percent of people older than 40 years of age. Paget's disease is more common in males than females. Rates of Paget's disease are about 50 percent higher in men than in women.

About 15 percent of people with Paget's disease also have a family member with the disease. In cases where the disease is familial, it is inherited in an autosomal dominant fashion, although not all people that inherit the affected version of the genes will express the disease (incomplete penetrance).

The incidence of Paget's disease varies considerably with geographic location. Paget's predominantly affects people of European descent, whereas people of African, Asian, or Indian descent are less commonly affected. Paget's disease is less common in Switzerland and Scandinavia than in the rest of Western Europe. Paget's disease is uncommon in the native populations of North and South America, Africa, Asia, and the Middle East. When an individual from these regions does develop Paget's disease, there is typically some European ancestry present.

Arthritis mutilans occurs mainly in people who have pre-existing psoriatic arthritis, but can occur, if less often, in advanced rheumatoid arthritis; it can also occur independently. Psoriasis and psoriatic arthritis are interrelated heritable diseases, occurring with greater heritable frequency than rheumatoid arthritis, primary Sjogren's syndrome and thyroid disease. Psoriasis affects 2–3% of the Caucasian population, and psoriatic arthritis affects up to 30% of those. Arthritis mutilans presents in about 5–16% of psoriatic arthritis cases, involves osteolysis of the DIP and PIP joints, and can include bone edema, bone erosions, and new bone growth. Most often psoratic arthitis is seronegative for rheumatoid factor (occurring in only about 13% of cases), and has genetic risk factor overlap with ankylosing spondylitis with HLA-B27, IL-23R77, and IL-1, however, as of 2016, immunopathogenesis is unclear.

More than 1 in 2 people with OI also have dentinogenesis imperfecta (DI) - a congenital disorder of formation of dentine. Dental treatment may pose as a challenge as a result of the various deformities, skeletal and dental, due to OI. Children with OI should go for a dental check-up as soon as their teeth erupt, this may minimize tooth structure loss as a result of abnormal dentine, and they should be monitored regularly to preserve their teeth and oral health.

Hip dysplasia may be caused by a femur that does not fit correctly into the pelvic socket, or poorly developed muscles in the pelvic area. Large and giant breeds are most susceptible to hip dysplasia (possibly due to the body mass index (BMI) of the individual animal, though, many other breeds can suffer from it. The Orthopedic Foundation for Animals maintains a list of top 100 breeds affected.

To reduce pain, the animal will typically reduce its movement of that hip. This may be visible as "bunny hopping", where both legs move together, or less dynamic movement (running, jumping), or stiffness. Since the hip cannot move fully, the body compensates by adapting its use of the spine, often causing spinal, stifle (a dog's knee joint), or soft tissue problems to arise.

The causes of hip dysplasia are considered heritable, but new research conclusively suggests that environment also plays a role. To what degree the causality is genetic and what portion environmental is a topic of current debate. Neutering a dog, especially before the dog has reached an age of full developmental maturity, has been proven to almost double the chance he or she will develop hip dysplasia versus intact dogs or dogs that were neutered after reaching adulthood Other environmental influences include overweight condition, injury at a young age, overexertion on the hip joint at a young age, ligament tear at a young age, repetitive motion on forming joint (i.e. jogging with puppy under the age of 1 year). As current studies progress, greater information may help provide procedures to effectively reduce the occurrence of this condition.

The problem almost always appears by the time the dog is 18 months old. The defect can be anywhere from mild to severely crippling, and can eventually cause severe osteoarthritis.

It is most common in medium-large pure bred dogs, such as Newfoundlands, German Shepherd Dogs, retrievers (such as Labradors, Tollers, or Goldens), rottweilers and Mastiff, but also occurs in some smaller breeds such as spaniels and pugs.

Osteoarthritis, a common symptom associated with Canine Hip Dysplasia in German Shepherds ultimately results in pain and inflammation. The causes are from bone degradation in which the bone is less rigid, cartilage dissipates and structure of joints becomes weak.

Diet can have a major impact for German Shepherds that are exposed to Canine Hip Dysplasia. Incorporating Omega-3 fatty acids such as Docosahexaenoic acid(DHA) and Eicosapentaenoic acid(EPA) into the diet can result in improved symptoms of the disease. Omega 3 fatty acids can help decrease inflammation that occurs from osteoarthritis, as well as improvement in locomotion of dogs who have the disease. EPA and DHA can be supplemented into the diet through fish oils and in return is beneficial for reducing joint inflammation.

Glucosamine and Chondroitin sulfate are Nutraceuticals that can also be added into the diet to help treat osteoarthritis and its quality of life reducing effects. Both nutraceuticals help with improvement of cartilage, joint health and repairing of tissues. This inclusion will allow for a stronger support and reduced negative effects of osteoarthritis. Another nutrient that can help improve the structural support of the body in German Shepherds is Vitamin C. Vitamin C contributes to the building blocks of collagen that can help to strengthen the joints.

Blount's disease occurs in young children and adolescents. The cause is unknown but is thought to be due to the effects of weight on the growth plate. The inner part of the tibia, just below the knee, fails to develop normally, causing angulation of the bone.

Unlike bowlegs, which tend to straighten as the child develops, Blount's disease is progressive and the condition worsens. It can cause severe bowing of the legs and can affect one or both legs.

This condition is more common among children of African ancestry. It is also associated with obesity, short stature, and early walking. There does not appear to be an obvious genetic factor.

Pseudoachondroplasia is inherited in an autosomal dominant manner, though one case of a very rare autosomal recessive form has been documented. The offspring of affected individuals are at 50% risk of inheriting the mutant allele. Prenatal testing by molecular genetic examination is available if the disease-causing mutation has been identified in an affected family member (Hecht et al. 1995).

Perthes' disease is one of the most common hip disorders in young children, occurring in roughly 5.5 of 100,000 children per year. The lifetime risk of a child developing the disease is about one per 1,200 individuals. Boys are affected about three to five times more often than girls. New cases of Perthes' disease rarely occur after age 14 years (if diagnosed after 14 years of age, then it is usually old disease from early in childhood or avascular necrosis from an alternative cause).

White northern Europeans appear to be affected more frequently than other races, though a paucity of reliable epidemiology exists in the Southern Hemisphere. Children of sufferers of the disease themselves may have a very slightly increased risk, though it is unclear if this is because of a genetic predisposition, or a shared environmental factor. It is most commonly seen in persons aged three to 12 years, with a median of six years of age. The UK incidence rates show an intriguing pattern with low incidence rates in London, and a progressive increase in disease in more northerly areas (maximal in Scotland). Some evidence suggests, at least in developed countries, more socioeconomically deprived communities have a greater risk of disease (a similar trend to diseases such as adult heart disease), though the reason for this remains unknown. One possible explanation that has been considered is tobacco smoke exposure, though this is significantly confounded by the strong socioeconomic gradient common to both smoking and Perthes' disease. Dietary factors of the child, and of the mother during pregnancy, are of interest to the research groups.

Several risk factors of CMC OA of the thumb are known. Each of these risk factors does not cause CMC OA by itself, but acts as a predisposing factor influencing the process of OA in some way. Risk factors include: female gender, suffering from obesity, repetitive heavy manual labor, familial predisposition and hormonal changes, such as menopause.

Children younger than 6 have the best prognosis, since they have time for the dead bone to revascularize and remodel, with a good chance that the femoral head will recover and remain spherical after resolution of the disease. Children who have been diagnosed with Perthes' disease after the age of 10 are at a very high risk of developing osteoarthritis and coxa magna. When an LCP disease diagnosis occurs after age 8, a better outcome results with surgery rather than nonoperative treatments. Shape of femoral head at the time when Legg-Calve Perthes disease heals is the most important determinant of risk for degenerative arthritis; hence, the shape of femoral head and congruence of hip are most useful outcome measures.

Fairbank's disease or multiple epiphyseal dysplasia (MED) is a rare genetic disorder (dominant form: 1 in 10,000 births) that affects the growing ends of bones. Long bones normally elongate by expansion of cartilage in the growth plate (epiphyseal plate) near their ends. As it expands outward from the growth plate, the cartilage mineralizes and hardens to become bone (ossification). In MED, this process is defective.

Pseudoachondroplasia is one of the most common skeletal dysplasias affecting all racial groups. However, no precise incidence figures are currently available (Suri et al. 2004).

CMC OA is the most common form of OA affecting the hand. Dahaghin et al. showed that about 15% of women and 7% of men between 50 and 60 years of age suffer from CMC OA of the thumb. However, in about 65% of people older than 55 years, radiologic evidence of OA was present without any symptoms. Armstrong et al. reported a prevalence of 33% in postmenopausal women, of which one third was symptomatic, compared to 11% in men older than 55 years. This shows CMC OA of the thumb is significantly more prevalent in women, especially in postmenopausal women, compared to men.

Like many other joints throughout the human body, facets can experience natural degeneration from constant use. Over time, the cartilage within the joints can naturally begin to wear out, allowing it to become thin or disappear entirely which, in turn, allows the conjoining vertebrae to rub directly against one another with little or no lubricant or separation. A result of this rubbing is often swelling, inflammation or other painful symptoms.

Over time, the body will naturally respond to the instability within the spine by developing bone spurs, thickened ligaments or even cysts that can press up against or pinch the sensitive nerve roots exiting the spinal column.

While primarily caused through natural wear and tear, advanced facet syndrome can also occur as a result of injury to the spine, degenerative disease or lifestyle choices. These causes can include:

- An unexpected, traumatic event such as a car accident, significant fall or high impact sports injury.

- Osteoarthritis

- Spondylolisthesis

- Obesity

- Smoking

- Malnutrition

- Lack of physical exercise or daily activity

55% of facet syndrome cases occur in cervical vertebrae, and 31% in lumbar. Facet syndrome can progress to spinal osteoarthritis, which is known as spondylosis. Pathology of the C1-C2 (atlantoaxial) joint, the most mobile of all vertebral segments, accounts for 4% of all spondylosis.

Elbow Dysplasia is a significant genetically determined problem in many breeds of dog, often manifesting from puppyhood and continuing for life. In elbow dysplasia, the complex elbow joint suffers from a structural defect, often related to its cartilage. This initial condition, known as a "primary lesion", causes an abnormal level of wear and tear and gradual degradation of the joint, at times disabling or with chronic pain. Secondary processes such as inflammation and osteoarthritis can arise from this damage which increase the problem and add further problems of their own.

This is an autosomal recessive osteochondrodysplasia that maps to chromosome 1q21. Deficiency of Cathepsin K, a cysteine protease in osteoclasts, is known to cause this condition. Cathepsin K became a much sought-after drug target in osteoporosis after the cause of pycnodysostosis was discovered. The disease consistently causes short stature. The height of adult males with the disease is less than . Adult females with the syndrome are even shorter.

The disease has been named Toulouse-Lautrec syndrome, after the French artist Henri de Toulouse-Lautrec, who may have had the disease. In 1996, the defective gene responsible for pycnodysostosis was located, offering accurate diagnosis, carrier testing and a more thorough understanding of this disorder.

Osteogenesis imperfecta is a rare condition in which bones break easily. There are multiple genetic mutations in different genes for collagen that may result in this condition. It can be treated with some drugs to promote bone growth, by surgically implanting metal rods in long bones to strengthen them, and through physical therapy and medical devices to improve mobility.

The most common cause is osteochondrosis, which is a disease of the joint cartilage, and specifically Osteochondritis dissecans (OCD or OD), the separation of a flap of cartilage from the joint surface as a result of avascular necrosis, which in turn arises from failed blood flow in the subchondral bone. Other common causes of elbow dysplasia included ununited anconeal process (UAP) and fractured or ununited medial coronoid process (FCP or FMCP).

In OCD, the normal change of cartilage to bone in the development of the joint fails or is delayed. The cartilage continues to grow and may split or become necrotic. The cause is uncertain, but possibly includes genetics, trauma, and nutrition (including excessive calcium and decreased Vitamin C intake). OCD lesions are found in the elbow at the medial epicondyle of the humerus. Specific conditions related to OCD include fragmentation of the medial coronoid process of the ulna (FMCP) and an ununited anconeal process of the ulna (UAP). All types of OCD of the elbow are most typically found in large breed dogs, with symptoms starting between the ages of 4 to 8 months. Males are affected twice as often as females. The disease often affects both elbows (30 to 70 percent of the time), and symptoms include intermittent lameness, joint swelling, and external rotation and abduction of the paw. Osteoarthritis will develop later in most cases.

UAP is caused by a separation from the ulna of the ossification center of the anconeal process. FMCP is caused by a failure of the coronoid process to unite with the ulna. OCD of the medial epicondyle of the humerus is caused by disturbed endochondral fusion of the epiphysis of the medial epicondyle with the distal end of the humerus, which may in turn be caused by avulsion of the epiphysis.

With adaptive equipment such as crutches, wheelchairs, splints, grabbing arms, or modifications to the home, many individuals with OI can maintain a significant degree of autonomy.