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.

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.

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.

There are few good estimates of prevalence for pes cavus in the general community. While pes cavus has been reported in between 2 and 29% of the adult population, there are several limitations of the prevalence data reported in these studies. Population-based studies suggest the prevalence of the cavus foot is approximately 10%.

Pes cavus may be hereditary or acquired, and the underlying cause may be neurological, orthopedic, or neuromuscular. Pes cavus is sometimes—but not always—connected through Hereditary Motor and Sensory Neuropathy Type 1 (Charcot-Marie-Tooth disease) and Friedreich's Ataxia; many other cases of pes cavus are natural.

The cause and deforming mechanism underlying pes cavus is complex and not well understood. Factors considered influential in the development of pes cavus include muscle weakness and imbalance in neuromuscular disease, residual effects of congenital clubfoot, post-traumatic bone malformation, contracture of the plantar fascia, and shortening of the Achilles tendon.

Among the cases of neuromuscular pes cavus, 50% have been attributed to Charcot-Marie-Tooth disease, which is the most common type of inherited neuropathy with an incidence of 1 per 2,500 persons affected. Also known as Hereditary Motor and Sensory Neuropathy (HMSN), it is genetically heterogeneous and usually presents in the first decade of life with delayed motor milestones, distal muscle weakness, clumsiness, and frequent falls. By adulthood, Charcot-Marie-Tooth disease can cause painful foot deformities such as pes cavus. Although it is a relatively common disorder affecting the foot and ankle, little is known about the distribution of muscle weakness, severity of orthopaedic deformities, or types of foot pain experienced. There are no cures or effective courses of treatment to halt the progression of any form of Charcot-Marie-Tooth disease.

The development of the cavus foot structure seen in Charcot-Marie-Tooth disease has been previously linked to an imbalance of muscle strength around the foot and ankle. A hypothetical model proposed by various authors describes a relationship whereby weak evertor muscles are overpowered by stronger invertor muscles, causing an adducted forefoot and inverted rearfoot. Similarly, weak dorsiflexors are overpowered by stronger plantarflexors, causing a plantarflexed first metatarsal and anterior pes cavus.

Pes cavus is also evident in people without neuropathy or other neurological deficit. In the absence of neurological, congenital, or traumatic causes of pes cavus, the remaining cases are classified as being ‘idiopathic’ because their aetiology is unknown.

Pigeon toe (also known as metatarsus varus, metatarsus adductus, in-toe gait, intoeing or false clubfoot) is a condition which causes the toes to point inward when walking. It is most common in infants and children under two years of age and, when not the result of simple muscle weakness, normally arises from underlying conditions, such as a twisted shin bone or an excessive anteversion (femoral head is more than 15° from the angle of torsion) resulting in the twisting of the thigh bone when the front part of a person's foot is turned in.

Severe cases are considered a form of clubfoot.

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.

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.

The tibia or lower leg slightly or severely twists inward when walking or standing.

"Infant’s persistent thumb-clutched hand, flexion-adduction deformity of the thumb, pollex varus, thumb in the hand deformity."

Congenital clasped thumb describes an anomaly which is characterized by a fixed thumb into the palm at the metacarpophalangeal joint in one or both hands.

The incidence and genetic background are unknown. A study of Weckesser et al. showed that boys are twice as often affected with congenital clasped thumb compared to girls. The anomaly is in most cases bilateral (present in both hands).

A congenital clasped thumb can be an isolated anomaly, but can also be attributed to several syndromes.

There are many hypotheses about how clubfoot develops. Some hypothesis include: environmental factors, genetics, or a combination of both. Research has not yet pinpointed the root cause, but many findings agree that "it is likely there is more than one different cause and at least in some cases the phenotype may occur as a result of a threshold effect of different factors acting together."

Some researchers hypothesize, from the early development stages of humans, that clubfoot is formed by a malfunction during gestation. Early amniocentesis (11–13 wks) is believed to increase the rate of clubfoot because there is an increase in potential amniotic leakage from the procedure. Underdevelopment of the bones and muscles of the embryonic foot may be another underlying cause. In the early 1900s it was thought that constriction of the foot by the uterus contributed to the occurrence of clubfoot.

Underdevelopment of the bones also affects the muscles and tissues of the foot. Abnormality in the connective tissue causes "the presence of increased fibrous tissue in muscles, fascia, ligaments and tendon sheaths".

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%.

Cubitus valgus is a medical deformity in which the forearm is angled away from the body to a greater degree than normal when fully extended. A small degree of cubitus valgus (known as the carrying angle) is acceptable and occurs in the general population.

When present at birth, it can be an indication of Turner syndrome or Noonan syndrome. It can also be acquired through fracture or other trauma. The physiological cubitus valgus varies from 3° to 29°. Women usually have a more pronounced Cubitus valgus than men. The deformity can also occur as a complication of fracture of the lateral condyle of the humerus, which may lead to tardy/delayed ulnar nerve palsy.

The opposite condition is cubitus varus ().

Hallux varus, or sandal gap, is a deformity of the great toe joint where the hallux is deviated medially (towards the midline of the body) away from the first metatarsal bone. The hallux usually moves in the transverse plane. Unlike hallux valgus, also known as hallux abducto valgus or bunion, hallux varus is uncommon in the West but it is common in cultures where the population remains unshod.

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.

Clubfoot is a birth defect where one or both feet are rotated inwards and downwards. The affected foot, calf, and leg may be smaller than the other. In about half of those affected, both feet are involved. Most cases are not associated with other problems. Without treatment, people walk on the sides of their feet which causes issues with walking.

The exact cause is usually unclear. A few cases are associated with distal arthrogryposis or myelomeningocele. If one identical twin is affected there is a 33% chance the other one will be as well. Diagnosis may occur at birth or before birth during an ultrasound exam.

Initial treatment is most often with the Ponseti method. This involves moving the foot into an improved position followed by casting, which is repeated at weekly intervals. Once the inward bending is improved, the Achilles tendon is often cut and braces are worn until the age of four. Initially the brace is worn nearly continuously and then just at night. In about 20% of cases further surgery is required.

Clubfoot occurs in about one in 1,000 newborns. The condition is less common among the Chinese and more common among Maori. Males are affected about twice as often as females. Treatment can be carried out by a range of healthcare providers and can generally be achieved in the developing world with few resources.

Future research into posterolateral injuries will focus on both the treatment and diagnosis of these types of injuries to improve PLC injury outcomes. Studies are needed to correlate injury patterns and mechanisms with clinical measures of knee instability and laxity.

In 2010 national statistics was done by Agency for Healthcare Research and Quality for posterior cruciate ligaments injuries. They found that 463 patients were discharge for having some type of PCL injury. The 18- to 44-year-old age group was found to have the highest injuries reported (figure 1). One reason why this age group consists of the majority of injuries to the PCL is because people are still very active in sports at this age. Men were also reported having more injuries to the PCL (figure 3).

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.

The majority of hip fractures are the result of a fall, particularly in the elderly. Therefore, identifying why the fall occurred, and implementing treatments or changes, is key to reducing the occurrence of hip fractures. Multiple contributing factors are often identified. These can include environmental factors and medical factors (such as postural hypotension or co-existing disabilities from disease such as Stroke or Parkinson's Disease which cause visual and/or balance impairments). A recent study has identified a high incidence of undiagnosed cervical spondylotic myelopathy (CSM) amongst patients with a hip fracture. This is relatively unrecognised consequent of CSM.

Additionally, there is some evidence to systems designed to offer protection in the case of a fall. Hip protectors, for example appear to decrease the number of hip fractures among the elderly. They; however, are not often used.

Hip fractures are seen globally and are a serious concern at the individual and population level. By 2050 it is estimated that there will be 6 million cases of hip fractures worldwide. One study published in 2001 found that in the US alone, 310,000 individuals were hospitalized due to hip fractures, which can account for 30% of Americans who were hospitalized that year. Another study found that in 2011, femur neck fractures were among the most expensive conditions seen in US hospitals, with an aggregated cost of nearly $4.9 billion for 316,000 inpatient hospitalizations. Rates of hip fractures is declining in the United States, possibly due to increased use of bisphosphonates and risk management. Falling, poor vision, weight and height are all seen as risk factors. Falling is one of the most common risk factors for hip fractures. Approximately 90% of hip fractures are attributed to falls from standing height.

Given the high morbidity and mortality associated with hip fractures and the cost to the health system, in England and Wales, the National Hip Fracture Database is a mandatory nationwide audit of care and treatment of all hip fractures.

Diagnosing the congenital clasped thumb is difficult in the first three to four months of life, as it is normal when the thumb is clutched into the palm in these first months.

Diagnoses that cause the same flexion or adduction abnormalities of the thumb are:

- Congenital clasped thumb

- Congenital Trigger thumb (flexion of the interphalangeal joint) - Trigger finger

- Spasticity: overstimulation of muscles

Syndrome associated flexion-adduction of the thumb:

- Freeman-Sheldon syndrome (a congenital, heritable affection of the face, the hands, the feet and some joints)

- Distal arthrogryposis

- MASA syndrome

- X-linked hydrocephalus

- Adducted thumb syndrome

- Waardenburg syndrome

- Whistling face syndrome (Freeman-Sheldon syndrome)

- Digitotalar dysmorphism

- Multiple pterygium syndrome

The meniscal tear is the most common knee injury. A meniscal tear tends to be more frequent in sports that have rough contact or pivoting sports such as soccer. The meniscal tear is more common in males than females. The ratio is about two and a half males to one female. Males between the ages of thirty-one and forty tend to tear their meniscus more frequently than younger men. Females on the other hand, seem to be more likely to tear their meniscus between the ages of eleven and twenty. People who work in straining jobs such as construction or pro athletes are also more likely to have a meniscal tear because of all the different tensions of their knees. According to the United States National Library of Medicine, the isolated medial meniscal tear occurs more frequently than any other tear associated with the meniscus. The prevalence of meniscus tears is the same for both knees. In a few different studies the BMI of a person can have a greater effect on the frequency of a meniscus tear because having a higher BMI will result in more weight on the joints which can cause the knee to be non-aligned which causes more weight on the muscles resulting in an easier tear. In 2008 the U.S Department of Health and Human Services reported a combined total of 2,295 discharges for the principal diagnosis of tear of lateral cartilage/meniscus (836.0), tear of medial cartilage/meniscus (836.1), and tear of cartilage/meniscus (836.2). Females had a total of 53.49% discharges while males had 45.72%. Individuals between the ages of 45–68 years had an average of 31.73% discharges followed by age group 65–84 with 28.82%. The average length of stay for a patient diagnosed with torn menisci was 2.7 days for males and 3.7 days for females. There was a report of 6,941 hospital discharges for knee repair. Individuals between 18–44 years of age were among the highest with 37.37% total of discharges followed by the age group 45–64 with a percentage of 36.34%. Males had a slightly higher number of discharges (50.78%) than females (48.66%). The average length of stay for both male and female patients in a hospital setting was 3.1.

According to the posterior cruciate ligament injuries only account for 1.5 percent of all knee injuries (figure 2). If it is a single injury to the posterior cruciate ligament that requires surgery only accounted for 1.1 percent compared to all other cruciate surgeries but when there was multiple injuries to the knee the posterior cruciate ligament accounted for 1.2 percent of injuries.

The Segond fracture is a type of avulsion fracture (soft tissue structures tearing off bits of their bony attachment) of the lateral tibial condyle of the knee, immediately beyond the surface which articulates with the femur.