Some studies suggest a hormonal link. Specifically, the hormone relaxin has been indicated.

A genetic factor is indicated since the trait runs in families and there is an increased occurrence in some ethnic populations (e.g., Native Americans, Lapps / Sami people). A locus has been described on chromosome 13. Beukes familial dysplasia, on the other hand, was found to map to an 11-cM region on chromosome 4q35, with nonpenetrant carriers not affected.

Hip dysplasia is considered to be a multifactorial condition. That means that several factors are involved in causing the condition to manifest.

The cause of this condition is unknown; however, some factors of congenital hip dislocation are through heredity and racial background. It is also thought that the higher rates in some ethnic groups (such as some Native American groups) is due to the practice swaddling of infants, which is known to be a potential risk factor for developing dysplasia. It also has a low risk in African Americans and southern Chinese.

Jaw dislocation is common for people who are in car, motorcycle or related accidents and also sports related activities. This injury does not pin point specific ages or genders because it could happen to anybody. People who dislocate their jaw do not usually seek emergency medical care. In most cases, jaw dislocations are acute and can be altered by minor manipulations. It was reported from one study that over a seven-year period at an emergency medical site, with 100,000 yearly visits, there were only 37 patients that were seen for a dislocated jaw.

The etiology of the Galeazzi fracture is thought to be a fall that causes an axial load to be placed on a hyperpronated forearm. However, researchers have been unable to reproduce the mechanism of injury in a laboratory setting.

After the injury, the fracture is subject to deforming forces including those of the brachioradialis, pronator quadratus, and thumb extensors, as well as the weight of the hand. The deforming muscular and soft-tissue injuries that are associated with this fracture cannot be controlled with plaster immobilization.

The incidence of Hill–Sachs lesion is not known with certainty. It has been reported to be present in 40% to 90% of patients presenting with anterior shoulder instability, that is subluxation or dislocation. In those who have recurrent events, it may be as high as 100%. Its presence is a specific sign of dislocation and can thus be used as an indicator that dislocation has occurred even if the joint has since regained its normal alignment. The average depth of Hill–Sachs lesion has been reported as 4.1 mm. Large, engaging Hill-Sachs fractures can contribute to shoulder instability and will often cause painful clicking, catching, or popping.

Galeazzi fractures account for 3-7% of all forearm fractures. They are seen most often in males. Although Galeazzi fracture patterns are reportedly uncommon, they are estimated to account for 7% of all forearm fractures in adults. They are associated with a fall on an outstretched arm.

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.

Most commonly due to anterior shoulder dislocation caused by hyperabduction and external rotation of the arm. Usually in young men who play contact sports (E.g. rugby, football, volleyball, basketball, etc.). Frequent anterior (frontward) subluxation also poses a great risk factor.

Post-traumatic cases are most likely to develop following surgery for a forearm fracture, this is more common with high-energy injuries where the bones are broken into many pieces (comminuted). It can also develop following soft tissue injury to the forearm where there is haematoma formation.

It is sometimes possible to correct the problem with surgery, though this has high failure rates for treatment of post-traumatic radioulnar synostosis.

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.

Specific populations at high risk of primary PFPS include runners, bicyclists, basketball players, young athletes and females.

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.

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

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.

The lesion is associated with anterior or posterior shoulder dislocation. When the humerus is driven from the glenohumeral cavity, its relatively soft head impacts against the anterior edge of the glenoid. The result is a divot or flattening in the posterolateral aspect of the humeral head, usually opposite the coracoid process. The mechanism which leads to shoulder dislocation is usually traumatic but can vary, especially if there is history of previous dislocations. Sports, falls, seizures, assaults, throwing, reaching, pulling on the arm, or turning over in bed can all be causes of anterior dislocation.

The Essex-Lopresti fracture is a fracture of the radial head with concomitant dislocation of the distal radio-ulnar joint and disruption of the interosseous membrane. The injury is named after Peter Essex-Lopresti who described it in 1951.

The radial head fracture is usually managed by open reduction internal fixation; if the fracture is too comminuted, a radial head implant can be used. Excision of the radial head should be avoided, as the radius will migrate proximally leading to wrist pain and loss of pronation and supination of the wrist. Delayed treatment of the radial head fracture will also lead to proximal migration of the radius.

The distal radio-ulnar joint dislocation can be reduced by supination of the forearm, and may be pinned in place for 6 weeks to allow healing of the interosseous membrane.

Humeral avulsion of the glenohumeral ligament (HAGL) is defined as an avulsion (tearing away) of the inferior glenohumeral ligament from the anatomic neck of the humerus. In other words, it occurs when we have disruption of the ligaments that join the humerus to the glenoid.

HAGL tends to occur in 7.5-9.3% of cases of anterior shoulder instability. Making it an uncommon cause of anterior shoulder instability.

Avulsion of this ligamentous complex may occur in three sites: glenoid insertion (40%), the midsubstance (35%) and the humeral insertion (25%).

A common cause is the supracondylar fracture of humerus. It can be corrected via a corrective osteotomy of the humerus and either internal or external fixation of the bone until union.

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

In dogs, hip dysplasia is an abnormal formation of the hip socket that, in its more severe form, can eventually cause crippling lameness and painful arthritis of the joints. It is a genetic (polygenic) trait that is affected by environmental factors. It is common in many dog breeds, particularly the larger breeds, and is the most common single cause of arthritis of the hips.

Bennett fracture is a fracture of the base of the first metacarpal bone which extends into the carpometacarpal (CMC) joint. This intra-articular fracture is the most common type of fracture of the thumb, and is nearly always accompanied by some degree of subluxation or frank dislocation of the carpometacarpal joint.

A cubitus varus deformity is more cosmetic than limiting of any function, however internal rotation of the radius over the ulna may be limited due to the overgrowth of the humerus. This may be noticeable during an activity such as using a computer mouse.

Most temporomandibular disorders (TMDs) are self-limiting and do not get worse. Simple treatment, involving self-care practices, rehabilitation aimed at eliminating muscle spasms, and restoring correct coordination, is all that is required. Nonsteroidal anti inflammatory analgesics (NSAIDs) should be used on a short-term, regular basis and not on an as needed basis. On the other hand, treatment of chronic TMD can be difficult and the condition is best managed by a team approach; the team consists of a primary care physician, a dentist, a physiotherapist, a psychologist, a pharmacologist, and in small number of cases, a surgeon. The different modalities include patient education and self-care practices, medication, physical therapy, splints, psychological counseling, relaxation techniques, biofeedback, hypnotherapy, acupuncture, and arthrocentesis.

As with most dislocated joints, a dislocated jaw can usually be successfully positioned into its normal position by a trained medical professional. Attempts to readjust the jaw without the assistance of a medical professional could result in worsening of the injury. The health care provider may be able to set it back into the correct position by manipulating the area back into its proper position. Numbing medications such as general anesthetics, muscle relaxants, or in some cases sedation, may be needed to relax the strong jaw muscle. In more severe cases, surgery may be needed to reposition the jaw, particularly if repeated jaw dislocations have occurred.