There are multiple classifications for the triphalangeal thumb. The reason for these different classifications is the heterogeneity in appearance of the TPT.

The classification according to Wood describes the shape of the extra phalanx: delta (Fig. 4), rectangular or full phalanx (Table 1). With the classification made by Buck-Gramcko a surgical treatment can be chosen (Table 1). Buck-Gramcko differentiates between six different shapes of the extra phalanx and associated malformations.

Table 1: Classifications of Wood and Buck-Gramcko

The timing of surgical interventions is debatable. Parents have to decide about their child in a very vulnerable time of their parenthood. Indications for early treatment are progressive deformities, such as syndactyly between index and thumb or transverse bones between the digital rays. Other surgical interventions are less urgent and can wait for 1 or 2 years.

There are several classifications for cleft hand, but the most used classification is described by Manske and Halikis see table 3. This classification is based on the first web space. The first web space is the space between the thumb and the index.

Table 3: Classification for cleft hand described by Manske and Halikis

The goals of surgical treatment are: reducing length of the thumb, creating a good functioning, a stable and non deviated joint and improving the position of the thumb if necessary. Hereby improving function of the hand and thumb.

In general the surgical treatment is done for improvement of the thumb function. However, an extra advantage of the surgery is the improvement in appearance of the thumb. In the past, surgical treatment of the triphalangeal thumb was not indicated, but now it is generally agreed that operative treatment improves function and appearance. Because an operation was not indicated in the past, there’s still a population with an untreated triphalangeal thumb. The majority of this population doesn’t want surgery, because the daily functioning of the hand is good. The main obstacle for the untreated patients might not be the diminished function, but the appearance of the triphalangeal thumb.

The timing of surgery differs between Wood and Buck-Gramcko. Wood advises operation between the age of six months and two years, while Buck-Gramcko advises to operate for all indications before the age of six years.

- For TPT types I and II of the Buck-Gramcko classification, the surgical treatment typically consists of removing the extra phalanx and reconstructing the ulnar collateral ligament and the radial collateral ligament if necessary.

- For type III of Buck-Gramcko classification proposable surgical treatments:

- For type IV of Buck-Gramcko classification the surgical treatment typically consists of an osteotomy which reduces the middle phalanx and arthrodesis of the DIP. This gives a shortening of 1 to 1.5 cm. In most cases, this technique is combined with a shortening, rotation and palmar abduction osteotomy at metacarpal level to correct for position and length of the thumb. The extensor tendons and the intrinsic muscles are shortened as well.

- For type V of the Buck-Gramcko classification the surgical treatment proposably consists of a "pollicization". With a pollicization the malpositioned thumb is repositioned, rotated and shortened, the above-described rotation reduction osteotomy of the first metacarpal can be performed as well.

- For type VI of the Buck-Gramcko classification, the surgical treatment typically consists of removing the additional mostly hypoplastic thumb(s). Further procedures of reconstruction of the triphalangeal thumb are performed according to the shape of the extra phalanx as described above.

Diagnosis is based on physical examination including radiographs of the hands and feet and imaging studies of the kidneys, bladder, and female reproductive tract. HOXA13 is the only gene known to be associated with HFGS. Approximately 60% of mutations are polyalanine expansions. Molecular genetic testing is clinically available.

Additional findings that may be present in HFGS according to the latest research are:

- Limited metacarpophalangeal flexion of the thumb or limited ability to oppose the thumb and fifth finger

- Hypoplastic thenar eminences

- Medial deviation of the great toe (hallux varus), a useful diagnostic sign when present

- Small great toenail

- Fifth-finger clinodactyly, secondary to a shortened middle phalanx

- Short feet

- Altered dermatoglyphics of the hands; when present, primarily involving distal placement of the axial triradius, lack of thenar or hypothenar patterning, low arches on the thumbs, thin ulnar loops (deficiency of radial loops and whorls), and a greatly reduced ridge count on the fingers

Radiographic findings

- Hypoplasia of the distal phalanx and first metacarpal of the thumbs and great toes

- Pointed distal phalanges of the thumb

- Lack of normal tufting of the distal phalanges of the great toes

- Fusions of the cuneiform to other tarsal bones or trapezium-scaphoid fusion of the carpals

- Short calcaneus

- Occasional bony fusions of the middle and distal phalanges of the second, third, fourth, or fifth toes

- Delayed carpal or tarsal maturation

- Metacarpophalangeal profile reflecting shortening of the first metacarpal, the first and second phalanges, and the second phalanx of the second and fifth digits

Urogenital Defects

Females may have the following:

- Vesicoureteral reflux secondary to ureteric incompetence

- Ectopic ureteral orifices

- Trigonal hypoplasia

- Hypospadiac urethra

- Subsymphyseal epispadias

- Patulous urethra

- Urinary incontinence (related to structural anomalies and weakness of the bladder sphincter muscle)

- Small hymenal opening

- Various degrees of incomplete Müllerian fusion with or without two cervices or a longitudinal vaginal septum

Males may have the following:

- Retrograde ejaculation (related to structural anomalies and weakness of the bladder sphincter muscle)

Type II should be managed conservatively whereas type I and Ia requires to be treated surgically. Surgery involves four major steps:

- Development of the calcaneal part of the foot

- Repositioning of the navicular bone

- New adjustment of the ankle, and

- Various stabilization measures including the Grice operation and transposition of various tendons.

Diagnosis of clubfoot deformity is by physical examination. Typically, a newborn is examined shortly after delivery with a head to toe assessment. Examination of the lower extremity and foot reveals the deformity, which may affect one or both feet. Examination of the foot shows four components of deformity.

- First, there is a higher arch on the inside of the foot. This component of the deformity can occur without the other aspects of clubfoot deformity. In isolation, this aspect of the deformity is called cavus deformity.

- Second, the forefoot is curved inward or medially (toward the big toe). This component of the deformity can occur without the other aspects of clubfoot deformity. In isolation, this aspect of the deformity is called metatarsus adductus.

- Third, the heel is turned inward. This is a natural motion of the heel and subtalar joint, typically referred to as inversion. In clubfoot deformity, the turning in (inversion) of the heel is fixed (not passively correctable) and considered a varus deformity.

- Fourth, and finally, the ankle is pointed downward. This is a natural motion of the ankle referred to as plantar flexion. In clubfoot deformity, this position is fixed (not correctable) and is referred to as equinus deformity.

A foot that shows all four components are diagnosed as having clubfoot deformity. These four components of a clubfoot deformity can be remembered with the acronym CAVE (cavus, forefoot adductus, varus, and equinus).

The severity of the deformity can also be assessed on physical exam, but is subjective to quantify. One way to assess severity is based on the stiffness of the deformity or how much it can be corrected with manual manipulation of the foot to bring it into a corrected position. Other factors used to assess severity include the presence of skin creases in the arch and at the heel and poor muscle consistency.

In some cases, it may be possible to detect the disease prior to birth during a prenatal ultrasound. Prenatal diagnosis by ultrasound can allow parents the opportunity to get information about this condition and make plans for treatment after their baby is born.

Other testing and imaging is typically not needed. Further testing may be needed if there are concerns for other associated conditions.

The symptoms would appear at birth or shortly after birth. The combination of physical symptoms on the child would suggest they have CHILD syndrome. A skin sample examined under a microscope would suggest the characteristics of the syndrome and an X-Ray of the trunk, arms, and legs would help to detect underdeveloped bones. A CT scan would help detect problems of the internal organs.

The cause of fibular hemimelia is unclear. Purportedly, there have been some incidents of genetic distribution in a family; however, this does not account for all cases. Maternal viral infections, embryonic trauma, teratogenic environmental exposures or vascular dysgenesis (failure of the embryo to form a satisfactory blood supply) between four and seven weeks gestation are considered possible causes.

In an experimental mouse model, change in the expression of a homeobox gene led to similar, but bilateral, fibular defects.

Oligodactyly (from the Ancient Greek "oligos" meaning "few" and δάκτυλος "daktylos" meaning "finger") is the presence of fewer than five fingers or toes on a hand or foot.

It is quite often incorrectly called "hypodactyly", but the Greek prefixes and are used for scales (e.g. in hypoglycaemia and hypercholesterolemia). This as opposed to or scales, where and should be used (e.g. in oligarchy and polygamy). Oligodactyly is therefore the opposite of polydactyly. Very rare, this medical condition usually has a genetic or familial cause.

Oligodactyly is sometimes a sign or symptom of several syndromes including Poland syndrome and Weyer Ulnar Ray Syndrome. It is a type of Dysmelia.

Ectrodactyly is an extreme instance of oligodactyly, involving the absence of one or more central digits of the hand or foot and is also known as split hand/split foot malformation (SHFM). The hands and feet of people with ectrodactyly are often described as "claw-like" and may include only the thumb and one finger (usually either the little finger, ring finger, or a syndactyly of the two) with similar abnormalities of the feet.

People with oligodactyly often have full use of the remaining digits and adapt well to their condition. They are not greatly hindered in their daily activities, if at all. Even those with the most extreme forms are known to engage in tasks that require fine control, such as writing and bootmaking as well as working as a cab driver.

Vadoma people of Zimbabwe have a high frequency of oligodactyly.

Fibular hemimelia or longitudinal fibular deficiency is "the congenital absence of the fibula and it is the most common congenital absence of long bone of the extremities." It is the shortening of the fibula at birth, or the complete lack thereof. In humans, the disorder can be noted by ultrasound in utero to prepare for amputation after birth or complex bone lengthening surgery. The amputation usually takes place at six months with removal of portions of the legs to prepare them for prosthetic use. The other treatments which include repeated corrective osteotomies and leg-lengthening surgery (Ilizarov apparatus) are costly and associated with residual deformity.

Diplopodia is a congenital anomaly in tetrapods that involves duplication of elements of the foot on the hind limb. It comes from the Greek roots diplo = "double" and pod = "foot". Diplopodia is often found in conjunction with other structural abnormalities and can be lethal. It is more extreme than polydactyly, the presence of extra digits.

Diagnosis is made on the basis of history and a high index of suspicion. On examination there is tenderness to palpation on navicular head. Radiographs reveal typical changes of increased density and narrowing of the navicular bone

Although the origin of the disease is unknown, there is speculation that it is an aggressive healing response to small tears in the plantar fascia, almost as if the fascia over-repairs itself following an injury. There is also some evidence that it might be genetic.

In the early stages, when the nodule is single and/or smaller, it is recommended to avoid direct pressure to the nodule(s). Soft inner soles on footwear and padding may be helpful.

MRI and sonogram (diagnostic ultrasound) are effective in showing the extent of the lesion, but cannot reveal the tissue composition. Even then, recognition of the imaging characteristics of plantar fibromatoses can help in the clinical diagnosis.

Surgery of Ledderhose's disease is difficult because tendons, nerves, and muscles are located very closely to each other. Additionally, feet have to carry heavy load, and surgery might have unpleasant side effects. If surgery is performed, the biopsy is predominantly cellular and frequently misdiagnosed as fibrosarcoma. Since the diseased area (lesion) is not encapsulated, clinical margins are difficult to define. As such, portions of the diseased tissue may be left in the foot after surgery. Inadequate excision is the leading cause of recurrence.

Radiotherapy has been shown to reduce the size of the nodules and reduce the pain associated with them. It is approximately 80% effective, with minimal side-effects.

Post-surgical radiation treatment may decrease recurrence. There has also been variable success in preventing recurrence by administering gadolinium. Skin grafts have been shown to control recurrence of the disease.

In few cases shock waves also have been reported to at least reduce pain and enable walking again. Currently in the process of FDA approval is the injection of collagenase. Recently successful treatment of Ledderhose with cryosurgery (also called cryotherapy) has been reported.

Cortisone injections, such as Triamcinolone, and clobetasol ointments have been shown to stall the progression of the disease temporarily, although the results are subjective and large-scale studies far from complete. Injections of superoxide dismutase have proven to be unsuccessful in curing the disease while radiotherapy has been used successfully on Ledderhose nodules.

The assessment for Smith-Finemen-Myers syndrome like any other mental retardation includes a detailed family history and physical exam that tests the mentality of the patient. The patient also gets a brain and skeletal imaging though CT scans or x-rays. They also does a chromosome study and certain other genetic biochemical tests to help figure out any other causes for the mental retardation.

The diagnosis of SFMS is based on visible and measurable symptoms. Until 2000, SFMS was not known to be associated with any particular gene. As of 2001, scientists do not yet know if other genes are involved in this rare disease. Generic analysis of the ATRX gene may prove to be helpful in diagnosis of SFMS.

Rocker bottom foot, also known as congenital vertical talus, is an anomaly of the foot. It is characterized by a prominent calcaneus (heel bone) and a convex rounded bottom of the foot. It gets its name from the foot's resemblance to the bottom of a rocking chair.

It can be associated with Edwards' syndrome (trisomy 18), Patau syndrome (trisomy 13), Trisomy 9 and mutation in the gene HOXD10.

It can also be associated with Charcots foot.

Treatment is usually with some combination of the Ponseti or French methods. The Ponseti method includes the following: casting together with manipulation, cutting the Achilles tendon, and bracing. The Ponseti method has been found to be effective in correcting the problem in those under the age of two. The French method involves realignment and tapping of the foot is often effective but requires a lot of effort by caregivers. Another technique known as Kite does not appear as good. In about 20% of cases further surgery is required.

Ainhum is an acquired and progressive condition, and thus differs from congenital annular constrictions. Ainhum has been much confused with similar constrictions caused by other diseases such as leprosy, diabetic gangrene, syringomyelia, scleroderma or Vohwinkel syndrome. In this case, it is called pseudo-ainhum, treatable with minor surgery or intralesional corticosteroids, as with ainhum. It has even been seen in psoriasis or it is acquired by the wrapping toes, penis or nipple with hairs, threads or fibers. Oral retinoids, such as tretinoin, and antifibrotic agents like tranilast have been tested for pseudo-ainhum. Impending amputation in Vohwinkel syndrome can sometimes be aborted by therapy with oral etretinate. It is rarely seen in the United States but often discussed in the international medical literature.

As the causes of local gigantism are varied, treatment depends on the particular condition. Treatment may range from antibiotics and other medical therapy, to surgery in order to correct the anatomical anomaly.

Soft tissue constriction on the medial aspect of the fifth toe is the most frequently presented radiological sign in the early stages. Distal swelling of the toe is considered to be a feature of the disease. In grade III lesions osteolysis is seen in the region of the proximal interphalangeal joint with a characteristic tapering effect. Dispersal of the head of the proximal phalanx is frequently seen. Finally, after autoamputation, the base of the proximal phalanx remains. Radiological examination allows early diagnosis and staging of ainhum. Early diagnosis is crucial to prevent amputation.

Doppler shows decreased blood flow in posterior tibial artery.

CHILD syndrome is a rare disorder with only 60 recorded cases worldwide thus far in literature.

A foot deformity is a disorder of the foot that can be congenital or acquired.

Such deformities can include hammer toe, club foot, flat feet, pes cavus, etc.

Most of these conditions are self-correcting during childhood. In the worst cases, surgery may be needed. Most of the time, this involves lengthening the Achilles tendon. Less severe treatment options for pigeon toe include keeping a child from crossing his or her legs, use of corrective shoes, and casting of the foot and lower legs, which is normally done before the child reaches 12 months of age or older.

If the pigeon toe is mild and close to the center, treatment may not be necessary.

Ballet has been used as a treatment for mild cases. Dance exercises can help to bend the legs outward.

Treatment usually involves resting the affected foot, taking pain relievers and trying to avoid putting pressure on the foot. In acute cases, the patient is often fitted with a cast that stops below the knee. The cast is usually worn for 6 to 8 weeks. After the cast is taken off, some patients are prescribed arch support for about 6 months. Also, moderate exercise is often beneficial, and physical therapy may help as well.

Prognosis for children with this disease is very good. It may persist for some time, but most cases are resolved within two years of the initial diagnosis. Although in most cases no permanent damage is done, some will have lasting damage to the foot. Also, later in life, Kohler's disease can spread to the hips.