Higher numbers indicate a more severe problem and greater likelihood of a poor final outcome.

It is a congenital subluxation or dislocation of the ulna's distal end, due to malformation of the bones. Sometimes, minor abnormalities of other bone structures, often caused by disease or injury, such as a fracture of the distal end of the radius with upward displacement of the distal fragment. The deformity varies in degree from a slight protrusion of the lower end of the ulna, to complete dislocation of the inferior radio-ulnar joint with marked radial deviation of the hand. Severe deformities are associated with congenital absence or hypoplasia of the radius.

The male:female rate of this disorder is 1:4. The incidence is unknown, and there is no described racial predominance. Even though Madelung's Deformity is considered a congenital disorder, symptoms sometimes aren't seen until adulthood. In most cases, symptoms find their onset during midchildhood. At this age, the relatively slower growth of the ulnar and palmar part of the radius, leads to an increasingly progressive deformity. Pain and deformity are the main symptoms patients present with. Typical clinical presentation consists of a short forearm, anterior-ulnar bow of the radius and a forward subluxation of the hand on the forearm. As mentioned before, the severity of the disorder varies greatly, which also leads to a spectrum of presentation.

Boutonniere deformity is a deformed position of the fingers or toes, in which the joint nearest the knuckle (the proximal interphalangeal joint, or PIP) is permanently bent toward the palm while the farthest joint (the distal interphalangeal joint, or DIP) is bent back away (PIP flexion with DIP hyperextension). It is commonly caused by injury or by an inflammatory condition like rheumatoid arthritis, or genetic conditions like Ehlers-Danlos syndrome.

Cubitus varus (varus means a deformity of a limb in which part of it is deviated towards the midline of the body) is a common deformity in which the extended forearm is deviated towards midline of the body.

Cubitus varus is often referred to as "Gunstock deformity", due to the crooked nature of the healing.

The "opposite" condition is cubitus valgus.

Madelung's deformity is usually characterized by malformed wrists and wrist bones and is often associated with Léri-Weill dyschondrosteosis. It can be bilateral (in both wrists) or just in the one wrist.

It has only been recognized within the past hundred years.

Swan neck deformity is a deformed position of the finger, in which the joint closest to the fingertip is permanently bent toward the palm while the nearest joint to the palm is bent away from it (DIP flexion with PIP hyperextension). It is commonly caused by injury or inflammatory conditions like rheumatoid arthritis or sometimes familial (congenital, like Ehlers-Danlos syndrome).

Swan neck deformity has many possible causes arising from the DIP, PIP, or even the MCP joints. In all cases, there is a stretching of the volar plate at the PIP joint to allow hyperextension, plus some damage to the attachment of the extensor tendon to the base of the distal phalanx that produces a hyperflexed mallet finger. Duck bill deformity is a similar condition affecting the thumb (which cannot have true swan neck deformity because it does not have enough joints).

Instances in which the medial epicondyle of the distal humerus is malformed due to the initial fracture at the humeral endplate may result in subluxation (snapping) of the ulnar nerve over the medial epicondyle with active flexion and extension of the elbow. In such instances, conductance of the ulnar nerve may be compromised due to chronic irritation, potentially resulting in irreversible ulnar neuropathy.

Children until the age of 3 to 4 have a degree of Genu Varum. The child sits with the soles of the feet facing one another; the tibia and femur are curved outwards; and, if the limbs are extended, although the ankles are in contact, there is a distinct space between the knee-joints. During the first year of life, a gradual change takes place. The knee-joints approach one another; the femur slopes downward and inward towards the knee joints; the tibia become straight; and the sole of the foot faces almost directly downwards.

While these changes are occurring, the bones, which at first consist principally of cartilage, are gradually becoming ossified. By the time a normal child begins to walk, the lower limbs are prepared, both by their general direction and by the rigidity of the bones which form them, to support the weight of the body.

Hammer toe most frequently results from wearing poorly fitting shoes that can force the toe into a bent position, such as excessively high heels or shoes that are too short or narrow for the foot. Having the toes bent for long periods of time can cause the muscles in them to shorten, resulting in the hammer toe deformity. This is often found in conjunction with bunions or other foot problems (e.g., a bunion can force the big toe to turn inward and push the other toes). It can also be caused by muscle, nerve, or joint damage resulting from conditions such as osteoarthritis, rheumatoid arthritis, stroke, Charcot–Marie–Tooth disease, complex regional pain syndrome or diabetes. Hammer toe can also be found in Friedreich's ataxia (GAA trinucleotide repeat).

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.

The symptoms of bunions include irritated skin around the bunion, pain when walking, joint redness and pain, and possible shift of the big toe toward the other toes. Blisters may form more easily around the site of the bunion as well.

The presence of bunions can lead to difficulties finding properly fitting footwear and may force a person to buy a larger size shoe to accommodate the width the bunion creates. If the bunion deformity becomes severe enough, the foot can hurt in different places even without the constriction of shoes. It is then considered as being a mechanical function problem of the forefoot.

A hammer toe or contracted toe is a deformity of the proximal interphalangeal joint of the second, third, or fourth toe causing it to be permanently bent, resembling a hammer. Mallet toe is a similar condition affecting the distal interphalangeal joint.

Claw toe is another similar condition, with dorsiflexion of the proximal phalanx on the lesser metatarsophalangeal joint, combined with flexion of both the proximal and distal interphalangeal joints. Claw toe can affect the second, third, fourth, or fifth toes.

The following factors may be involved in causing this deformity:

- Inherent laxity of the knee ligaments

- Weakness of biceps femoris muscle

- Instability of the knee joint due to ligaments and joint capsule injuries

- Inappropriate alignment of the tibia and femur

- Malunion of the bones around the knee

- Weakness in the hip extensor muscles

- Gastrocnemius muscle weakness (in standing position)

- Upper motor neuron lesion (for example, hemiplegia as the result of a cerebrovascular accident)

- Lower motor neuron lesion (for example, in post-polio syndrome)

- Deficit in joint proprioception

- Lower limb length discrepancy

- Congenital genu recurvatum

- Cerebral palsy

- Multiple sclerosis

- Muscular dystrophy

- Limited dorsiflexion (plantar flexion contracture)

- Popliteus muscle weakness

- Connective tissue disorders. In these disorders, there are excessive joint mobility (joint hypermobility) problems. These disorders include:

- Marfan syndrome

- Ehlers-Danlos syndrome

- Benign hypermobile joint syndrome

- Osteogenesis imperfecta disease

Coxa vara is a deformity of the hip, whereby the angle between the head and the shaft of the femur is reduced to less than 120 degrees. This results in the leg being shortened, and the development of a limp. It is commonly caused by injury, such as a fracture. It can also occur when the bone tissue in the neck of the femur is softer than normal, causing it to bend under the weight of the body. This may either be congenital or the result of a bone disorder. The most common cause of coxa vara is either congenital or developmental. Other common causes include metabolic bone diseases (e.g. Paget's disease of bone), post-Perthes deformity, osteomyelitis, and post traumatic (due to improper healing of a fracture between the greater and lesser trochanter). Shepherd's Crook deformity is a severe form of coxa vara where the proximal femur is severely deformed with a reduction in the neck shaft angle beyond 90 degrees. It is most commonly a sequela of osteogenesis imperfecta, Pagets disease, osteomyelitis, tumour and tumour-like conditions (e.g. fibrous dysplasia).

Coxa vara can happen in cleidocranial dysostosis.

Genu recurvatum is a deformity in the knee joint, so that the knee bends backwards. In this deformity, excessive extension occurs in the tibiofemoral joint. Genu recurvatum is also called knee hyperextension and back knee. This deformity is more common in women and people with familial ligamentous laxity. Hyperextension of the knee may be mild, moderate or severe.

The normal range of motion (ROM) of the knee joint is from 0 to 135 degrees in an adult. Full knee extension should be no more than 10 degrees. In genu recurvatum (back knee), normal extension is increased. The development of genu recurvatum may lead to knee pain and knee osteoarthritis.

Femoroacetabular Impingement (FAI), or hip impingement syndrome, may affect the hip joint in young and middle-aged adults and occurs when the ball shaped femoral head rubs abnormally or does not permit a normal range of motion in the acetabular socket. Damage can occur to the articular cartilage, or labral cartilage (soft tissue bumper of the socket), or both. Treatment options range from conservative to arthroscopic to open surgery.

Sprengel's deformity (also known as high scapula or congenital high scapula) is a rare congenital skeletal abnormality where a person has one shoulder blade that sits higher on the back than the other. The deformity is due to a failure in early fetal development where the shoulder fails to descend properly from the neck to its final position. The deformity is commonly associated with other conditions, most notably Klippel-Feil syndrome, congenital scoliosis including cervical scoliosis, fused ribs, the presence of an omovertebral bone and spina bifida. The left shoulder is the most commonly affected shoulder but the condition can be bilateral, meaning that both shoulders are affected. About 75% of all observed cases are girls. Treatment includes surgery in early childhood and physical therapy. Surgical treatment in adulthood is complicated by the risk of nerve damage when removing the omovertebral bone and when stretching the muscle tissue during relocation of the shoulder.

A bunion is a deformity of the joint connecting the big toe to the foot. The big toe often bends towards the other toes and the joint becomes red and painful. Onset is gradual. Complications may include bursitis or arthritis.

The exact cause is unclear. Proposed factors include wearing overly tight shoes, family history, and rheumatoid arthritis. Diagnosis is generally based on symptoms and supported by X-rays. A similar condition of the little toe is referred to as a bunionette.

Treatment may include proper shoes, orthotics, or NSAIDs. If this is not effective for improving symptoms, surgery may be done. It affects about 23% of adults. Females are affected more often than males. Usual age of onset is between 20 and 50 years old. The condition also becomes more common with age. It was first clearly described in 1870.

The scapula is small and rotated so that its inferior edge points toward the spine. There is a high correlation between Sprengel's deformity and the Klippel-Feil syndrome. Sometimes a bony connection is present between the elevated scapula and one of the cervical vertebrae, usually C5 or C6. This connection is known as the omovertebral bone.

The term "Colles fracture" is classically used to describe a fracture at the distal end of the radius, at its cortico-cancellous junction. However, now the term tends to be used loosely to describe any fracture of the distal radius, with or without involvement of the ulna, that has dorsal displacement of the fracture fragments. Colles himself described it as a fracture that “takes place at about an inch and a half (38mm) above the carpal extremity of the radius” and “the carpus and the base of metacarpus appears to be thrown backward”. The fracture is sometimes referred to as a "dinner fork" or "bayonet" deformity due to the shape of the resultant forearm.

Colles' fractures can be categorized according to several systems including Frykman, Gartland & Werley, Lidström, Nissen-Lie and the Older's classifications.

The clinical presentation varies depending on the stage of the disease from mild swelling to severe swelling and moderate deformity. Inflammation, erythema, pain and increased skin temperature (3–7 degrees Celsius) around the joint may be noticeable on examination. X-rays may reveal bone resorption and degenerative changes in the joint. These findings in the presence of intact skin and loss of protective sensation are pathognomonic of acute Charcot arthropathy.

Roughly 75% of patients experience pain, but it is less than what would be expected based on the severity of the clinical and radiographic findings.

Volkmann's contracture is a permanent flexion contracture of the hand at the wrist, resulting in a claw-like deformity of the hand and fingers. Passive extension of fingers is restricted and painful.

Coxa valga is a deformity of the hip where the angle formed between the head and neck of the femur and its shaft is increased, usually above 135 degrees. It is caused by a slipped epiphysis of the femoral head.

The differential diagnosis includes neuromuscular disorders (i.e. cerebral palsy, spinal dysraphism, poliomyelitis), skeletal dysplasias, and juvenile idiopathic arthritis.

The fracture is most commonly caused by people falling onto a hard surface and breaking their fall with outstretched hand (FOOSH)–falling with wrists flexed would lead to a Smith's fracture. Originally it was described in elderly and/or post-menopausal women. It usually occurs about three to five centimetres proximal to the radio-carpal joint with posterior and lateral displacement of the distal fragment resulting in the characteristic "dinner fork" or "bayonet" like deformity. Colles fracture is a common fracture in people with osteoporosis, second only to vertebral fractures.