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.

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.

Tibia shaft fractures are the most common long bone fractures. They account for approximately 4% of the fractures seen in the Medicare population.

OCD is a relatively rare disorder, with an estimated incidence of 15 to 30 cases per 100,000 persons per year. Widuchowski W "et al." found OCD to be the cause of articular cartilage defects in 2% of cases in a study of 25,124 knee arthroscopies. Although rare, OCD is noted as an important cause of joint pain in active adolescents. The juvenile form of the disease occurs in children with open growth plates, usually between the ages 5 and 15 years and occurs more commonly in males than females, with a ratio between 2:1 and 3:1. However, OCD has become more common among adolescent females as they become more active in sports. The adult form, which occurs in those who have reached skeletal maturity, is most commonly found in people 16 to 50 years old.

While OCD may affect any joint, the knee—specifically the medial femoral condyle in 75–85% of knee cases—tends to be the most commonly affected, and constitutes 75% of all cases. The elbow (specifically the capitulum of the humerus) is the second most affected joint with 6% of cases; the talar dome of the ankle represents 4% of cases. Less frequent locations include the patella, vertebrae, the femoral head, and the glenoid of the scapula.

The prognosis after different treatments varies and is based on several factors which include the age of the patient, the affected joint, the stage of the lesion and, most importantly, the state of the growth plate. It follows that the two main forms of osteochondritis dissecans are defined by skeletal maturity. The juvenile form of the disease occurs in open growth plates, usually affecting children between the ages of 5 and 15 years. The adult form commonly occurs between ages 16 to 50, although it is unclear whether these adults developed the disease after skeletal maturity or were undiagnosed as children.

The prognosis is good for stable lesions (stage I and II) in juveniles with open growth plates; treated conservatively—typically without surgery—50% of cases will heal. Recovery in juveniles can be attributed to the bone's ability to repair damaged or dead bone tissue and cartilage in a process called bone remodeling. Open growth plates are characterized by increased numbers of undifferentiated chondrocytes (stem cells) which are precursors to both bone and cartilaginous tissue. As a result, open growth plates allow for more of the stem cells necessary for repair in the affected joint. Unstable, large, full-thickness lesions (stage III and IV) or lesions of any stage found in the skeletally mature are more likely to fail non-operative treatment. These lesions offer a worse prognosis and surgery is required in most cases.

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.

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.

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.

Blount's disease is a growth disorder of the tibia (shin bone) that causes the lower leg to angle inward, resembling a bowleg.

It is also known as "tibia vara".

It is named after Walter Putnam Blount (1900–1992), an American pediatric orthopedic surgeon. It has also been known as Mau-Nilsonne Syndrome, after C. Mau and H. Nilsonne, who published early case reports of the condition.

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.

The proposed mechanism involves shear stress and lack of displacement due to the periosteum that is relatively strong compared to the elastic bone in young children.

Since approximately one third of the tibia lies directly beneath the skin, open fractures are common compared to other long bones. These open fractures are most commonly caused by high velocity trauma (e.g. motor vehicle collisions), while closed fractures most commonly occur from sports injuries or falls. Osteoporosis can be a contributing factor. Skiing and football (soccer) injuries are also common culprits.

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.

In most cases persisting after childhood, there is little or no effect on the ability to walk. Due to uneven stress and wear on the knees, however, even milder manifestations can see an accelerated onset of arthritis.

While genu valgum is often a symptom of genetic disorders it can be caused by poor nutrition. A major contributor to genu valgum is obesity, and far less commonly calcium and vitamin d deficiencies.

It occurs in older children at the end of growth. Variability in fracture pattern is due to progression of physeal closure as anterolateral part of distal tibial physis is the last to close. When the lateral physis is the only portion not fused, external rotation may lead to Tillaux or Triplane fractures.

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.

It occurs commonly in adolescents and older children. However, it does occur rarely in adults though it may be under reported because of difficulty in diagnosis.

If a child is sickly, either with rickets or any other ailment that prevents ossification of the bones, or is improperly fed, the bowed condition may persist. Thus the chief cause of this deformity is rickets. Skeletal problems, infection, and tumors can also affect the growth of the leg, sometimes giving rise to a one-sided bow-leggedness. The remaining causes are occupational, especially among jockeys, and from physical trauma, the condition being very likely to supervene after accidents involving the condyles of the femur.

Risk factors for developing shin splints include:

- Excessive pronation at subtalar joint

- Excessively tight calf muscles (which can cause excessive pronation)

- Engaging the medial shin muscle in excessive amounts of eccentric muscle activity

- Undertaking high-impact exercises on hard, noncompliant surfaces (ex: running on asphalt or concrete)

- Smoking and low fitness level

While medial tibial stress syndrome is the most common form of shin splints, compartment syndrome and stress fractures are also common forms of shin splints. Females are 1.5 to 3.5 times more likely to progress to stress fractures from shin splints. This is due in part to females having a higher incidence of diminished bone density and osteoporosis.

The degree of genu valgum can be estimated by the , which is the angle formed by a line drawn from the anterior superior iliac spine through the center of the patella and a line drawn from the center of the patella to the center of the tibial tubercle. In women, the Q angle should be less than 22 degrees with the knee in extension and less than 9 degrees with the knee in 90 degrees of flexion. In men, the Q angle should be less than 18 degrees with the knee in extension and less than 8 degrees with the knee in 90 degrees of flexion. A typical Q angle is 12 degrees for men and 17 degrees for women.

Tibial plateau fractures constitute 1% of all fractures. Peak age is 30–40 years old in men and 60-70 in women. Approximately half of the people who sustain a tibial plateau fracture are aged over 50 years old.

Toddler's fractures or childhood accidental spiral tibial (CAST) fractures are bone fractures of the distal (lower) part of the shin bone (tibia) in toddlers (aged 9 months-3 years) and other young children (less than 8 years). The fracture is found in the distal two thirds of the tibia in 95% of cases, is undisplaced and has a spiral pattern. It occurs after low-energy trauma, sometimes with a rotational component.

The ultimate cause for these conditions is unknown, but the most commonly cited cause factors are rapid growth, heredity, trauma (or overuse), anatomic conformation, and dietary imbalances; however, only anatomic conformation and heredity are well supported by scientific literature. The way that the disease is initiated has been debated. Although failure of chondrocyte differentiation, formation of a fragile cartilage, failure of blood supply to the growth cartilage, and bone necrosis all have been proposed as the starting point in the pathogenesis, recent literature strongly supports failure of blood supply to growth cartilage as most likely.

Women in sports such as association football, basketball, and tennis are significantly more prone to ACL injuries than men. The discrepancy has been attributed to gender differences in anatomy, general muscular strength, reaction time of muscle contraction and coordination, and training techniques.

Gender differences in ACL injury rates become evident when specific sports are compared. A review of NCAA data has found relative rates of injury per 1000 athlete exposures as follows:

- Men's basketball 0.07, women's basketball 0.23

- Men's lacrosse 0.12, women's lacrosse 0.17

- Men's football 0.09, women's football 0.28

The highest rate of ACL injury in women occurred in gymnastics, with a rate of injury per 1000 athlete exposures of 0.33

Of the four sports with the highest ACL injury rates, three were women's – gymnastics, basketball and soccer.

According to recent studies, female athletes are two to eight times more likely to strain their anterior cruciate ligament (ACL) in sports that involve cutting and jumping as compared to men who play the same particular sports (soccer, basketball, and volleyball). Differences between males and females identified as potential causes are the active muscular protection of the knee joint, the greater Q angle putting more medial torque on the knee joint, relative ligament laxity caused by differences in hormonal activity from estrogen and relaxin, intercondylar notch dimensions, and muscular strength.