Children in general are at greater risk because of their high activity levels. Children that have risk-prone behaviors are at even greater risk.

Over 2.5 million child abuse and neglect cases are reported every year, and thirty-five out of every hundred cases are physical abuse cases. Bone fractures are sometimes part of the physical abuse of children; knowing the symptoms of bone fractures in physical abuse and recognizing the actual risks in physical abuse will help forward the prevention of future abuse and injuries. Astoundingly, these abuse fractures, if not dealt with correctly, have a potential to lead to the death of the child.

Fracture patterns in abuse fractures that are very common with abuse are fractures in the growing part of a long bone (between the shaft and the separated part of the bone), fractures of the humeral shaft (long bone between the shoulder and elbow), ribs, scapula, outer end of the clavicle, and vertebra. Multiple fractures of varying age, bilateral fractures, and complex skull fractures are also linked to abuse. Fractures of varying ages occur in about thirteen percent of all cases.

Distal radius fractures are the most common fractures seen in adults, with incidence in females outnumbering incidence in males by a factor of 2-3. Men who sustain distal radius fractures are usually younger, generally in their fifth decade (vs. seventh decade in females). The elderly are more susceptible because of the osteopenia and osteoporosis commonly seen in this age group. The majority of these fractures are extra-articular (i.e. not involving the joint).

This is also a common injury in children which may involve the growth plate (Salter-Harris fracture).

In young adults, the injury is often severe as a greater force is necessary to produce the injury.

In humans, excessive forces caused by sudden bending upwards of the big toe, high heels, or a stumble can contribute to sesamoiditis. Once the sesamoid bone is injured it can be very difficult to cure, because every time you walk you put additional pressure on the sesamoid bone. Treatment in humans consists of anti-inflammatory medication, cortisone injections, strapping to immobilize the big toe, and orthotics with special accommodations to keep pressure off the affected bone.

In horses, sesamoiditis is generally caused by excess stress on the fetlock joint. Conformation that promotes sesamoiditis include long pasterns, or horses with long toes and low heels.

In children the outcome of distal radius fracture treatment in casts is usually very successful with healing and return to normal function expected. Some residual deformity is common but this often remodels as the child grows. In the elderly, distal radius fractures heal and may result in adequate function following non-operative treatment. A large proportion of these fractures occur in elderly people that may have less requirement for strenuous use of their wrists. Some of these patients tolerate severe deformities and minor loss of wrist motion very well even without reduction of the fracture. In this low demand group only a short period of immobilization is indicated as rapid mobilization improves functional outcome.

In younger patients the injury requires greater force and results in more displacement particularly to the articular surface. Unless an accurate reduction of the joint surface is obtained, these patients are very likely to have long term symptoms of pain, arthritis, and stiffness.

In the US, the annual incidence of stress fractures in athletes and military recruits ranges from 5% to 30%, depending on the sport and other risk factors. Women and highly active individuals are also at a higher risk. The incidence probably also increases with age due to age-related reductions in bone mass density (BMD). Children may also be at risk because their bones have yet to reach full density and strength. The female athlete triad also can put women at risk as disordered eating and osteoporosis can cause the bones to be severely weakened.

In children, whose bones are still developing, there are risks of either a growth plate injury or a greenstick fracture.

- A greenstick fracture occurs due to mechanical failure on the tension side. That is, since the bone is not so brittle as it would be in an adult, it does not completely fracture, but rather exhibits bowing without complete disruption of the bone's cortex in the surface opposite the applied force.

- Growth plate injuries, as in Salter-Harris fractures, require careful treatment and accurate reduction to make sure that the bone continues to grow normally.

- Plastic deformation of the bone, in which the bone permanently bends, but does not break, also is possible in children. These injuries may require an osteotomy (bone cut) to realign the bone if it is fixed and cannot be realigned by closed methods.

- Certain fractures mainly occur in children, including fracture of the clavicle and supracondylar fracture of the humerus.

By definition, a nonunion will not heal if left alone. Therefore the patient's symptoms will not be improved and the function of the limb will remain impaired. It will be painful to bear weight on it and it may be deformed or unstable. The prognosis of nonunion if treated depends on many factors including the age and general health of the patient, the time since the original injury, the number of previous surgeries, smoking history, the patient's ability to cooperate with the treatment. In the region of 80% of nonunions heal after the first operation. The success rate with subsequent surgeries is less.

Avascular necrosis usually affects people between 30 and 50 years of age; about 10,000 to 20,000 people develop avascular necrosis of the head of the femur in the US each year. When it occurs in children at the femoral head, it is known as Legg-Calvé-Perthes syndrome.

In the horse it occurs at the horse's fetlock. The sesamoid bones lie behind the bones of the fetlock, at the back of the joint, and help to keep the tendons and ligaments that run between them correctly functioning.

Usually periostitis (new bone growth) occurs along with sesamoiditis, and the suspensory ligament may also be affected. Sesamoiditis results in inflammation, pain, and eventually bone growth.

A malunion is when a fractured bone doesn’t heal properly. Some ways that it shows is by having the bone being twisted, shorter, or bent. Malunions can occur by having the bones improperly aligned when immobilized, having the cast taken off too early, or never seeking medical treatment after the break.

Malunions are painful and commonly produce swelling around the area, possible immobilization, and of the bone and tissue.

Smokers generally have lower bone density than non-smokers, so have a much higher risk of fractures. There also is evidence that smoking delays bone healing.

Clavicle fractures occur at 30–64 cases per 100,000 a year and are responsible for 2.6–5.0% of all fractures. This type of fracture occurs more often in males. About half of all clavicle fractures occur in children under the age of seven and is the most common pediatric fracture. Clavicle fractures involve roughly 5% of all fractures seen in hospital emergency admissions. Clavicles are the most commonly broken bone in the human body.

Malunions are presented by excessive swelling, twisting, bending, and possibly shortening of the bone. Patients may have trouble placing weight on or near the malunion. However, most commonly the presentation of a bend in the bone exhibits the diagnosis of a malunion.

No callus is formed. This is often due to impaired bony healing, for example due to vascular causes (e.g. impaired blood supply to the bone fragments) or metabolic causes (e.g. diabetes or smoking). Failure of initial union, for example when bone fragments are separated by soft tissue may also lead to atrophic non-union. Atrophic non-union can be treated by improving fixation, removing the end layer of bone to provide raw ends for healing, and the use of bone grafts.

Hyoid bones fractures represent 0.002% of all fractures; they are rare because the hyoid bone is well-protected by its location in the neck behind the mandible and in front of the cervical spine, as well as its mobility. 91.3% of hyoid bone fractures occur in men.

The prognosis for a horse with navicular syndrome is guarded. Many times the horse does not return to its former level of competition. Others are retired. Eventually all horses with the syndrome will need to lessen the strenuousness of their work, but with proper management, a horse with navicular syndrome can remain useful for some time.

Working on steep hills, galloping, and jumping all contribute to navicular syndrome, as they place greater stress on the DDF tendons, and may cause overextension of the pastern and coffin joints.

Regular exercise on hard or irregular ground increases concussion on the hoof, thus increasing the risk of navicular syndrome.

It is possible that standing can also increase the chance of navicular disease (such as a horse that spends most of the day in a stall with little turnout, as with some racehorses and show horses). Blood flow to the hoof decreases when the horse is not in motion. The horse is also constantly applying pressure to the navicular bones (which is intermittent as the horse moves).

Isolated and combined posterolateral knee injuries are difficult to accurately diagnose in patients presenting with acute knee injuries. The incidence of isolated posterolateral corner injuries has been reported to be between 13% and 28%. Most PLC injuries accompany an ACL or PCL tear, and can contribute to ACL or PCL reconstruction graft failure if not recognized and treated. A study by LaPrade "et al." in 2007 showed the incidence of posterolateral knee injuries in patients presenting with acute knee injuries and hemarthrosis (blood in the knee joint) was 9.1%.

An accessory navicular bone is an accessory bone of the foot that occasionally develops abnormally in front of the ankle towards the inside of the foot. This bone may be present in approximately 2-21% of the general population and is usually asymptomatic. When it is symptomatic, surgery may be necessary.

Surgery can be performed at any age because it does not alter any other bones.

Symptoms of an accessory navicular bone may include plantar fasciitis, bunions and heel spurs.

The main risk factors are bone fractures, joint dislocations, alcoholism, and the use of high dose steroids. Other risk factors include radiation therapy, chemotherapy, and organ transplantation. Osteonecrosis is also associated with cancer, lupus, sickle cell disease, HIV infection, Gaucher’s disease, and Caisson disease. The condition may also occur without any clear reason.

Bisphosphonates are associated with osteonecrosis of the mandible. Prolonged, repeated exposure to high pressures (as experienced by commercial and military divers) has been linked to AVN, though the relationship is not well understood.

Neck trauma, commonly by strangulation, athletic activities, and car accidents, is the cause of a hyoid bone fracture. Other causes include violent vomiting, gunshot wounds, and hanging.

Acute injury to the internal carotid artery (carotid dissection, occlusion, pseudoaneurysm formation) may be asymptomatic or result in life-threatening bleeding. They are almost exclusively observed when the carotid canal is fractured, although only a minority of carotid canal fractures result in vascular injury. Involvement of the petrous segment of the carotid canal is associated with a relatively high incidence of carotid injury.

The Geist classification divides the accessory navicular bones into three types.

- Type 1: An os tibiale externum is a 2–3 mm sesamoid bone in the distal posterior tibialis tendon. Usually asymptomatic.

- Type 2: Triangular or heart-shaped ossicle measuring up to 12 mm, which represents a secondary ossification center connected to the navicular tuberosity by a 1–2 mm layer of fibrocartilage or hyaline cartilage. Portions of the posterior tibialis tendon sometimes insert onto the accessory ossicle, which can cause dysfunction, and therefore, symptoms.

- Type 3: A cornuate navicular bone represents an enlarged navicular tuberosity, which may represent a fused Type 2 accessory bone. Occasionally symptomatic due to bunion formation.

Healing time varies based on age, health, complexity, and location of the break, as well as the bone displacement. For adults, a minimum of 2–6 weeks of sling immobilization is normally employed to allow initial bone and soft tissue healing; teenagers require slightly less, while children can often achieve the same level in two weeks. During this period, patients may remove the sling to practice passive pendulum range of motion exercises to reduce atrophy in the elbow and shoulder, but they are minimized to 15–20° off vertical. Depending on the severity of fracture, a person can begin to use the arm if comfortable with movement and no pain results. The final goal is to be able to have full range of motion with no pain; therefore, if any pain occurs, allowing for more recovery time is best. Depending on severity of the fracture, athletes involved in contact sports may need a longer period of rest to heal to avoid refracturing bone. A person should be able to return unrestricted to any sports or work by 3 months after the injury.