Syndactyly

or of the feet, which is characterized by the fusion of one or more fingers.

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More common than one might think, syndactyly can have various origins: it can be the result of unrecognizable causes, it can be a hereditary trait transmitted by the parents or, finally, it can be a sign of some genetic syndrome.
Between hands and feet, the hands suffer most from the presence of syndactyly; in the feet, in fact, the anomaly in question is generally without consequences (and is even more rare).
All this explains why syndactyly of the hands always requires surgery, while that of the feet only on certain occasions.
Diagnosis of syndactyly is simple and based on physical examination.

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In other words, doctors speak of syndactyly, when at least a couple of an individual's fingers and / or toes are fused together, rather than being normally separated.
In syndactyly, the anomalous fusion of the fingers can be limited to affecting the skin or it can also involve the bones; therefore, it is possible to be faced with cases of syndactyly, in which the fingers are joined only at the skin level, and cases of syndactyly, in which the fingers are joined at the skin level and at the bone level (c "is a" union between phalanges).

Important: the congenital aspect of syndactyly implies that the latter is present from birth.

Epidemiology

Syndactyly is a more common "anatomical anomaly than we think; according to statistics, in fact, about 1 in 2,500 newborns would be affected.
Between hands and feet, syndactyly tends to affect the hands more frequently: numbers in hand, 50% of syndactyly cases involve one hand.
For reasons still unknown, syndactyly is more common among individuals of the Caucasian population than among those of the African American and Asian population.
Finally, again for unknown reasons, syndactyly occurs more frequently in the male population than in the female one.

Origin of the name

The word "syndactyly" derives from the "union of the Greek terms" sin "(" συν ") and" daxtylos "(" δάκτυλος "):" sin "indicates the concept of" union "and can also be translated as" together ", while "daxtylos" means "finger".
Therefore, the literal meaning of "syndactyly" is "finger joined" and has the "intent to refer to" interdigital union (ie between the fingers), which characterizes the malformation in question.

of a fetus (therefore after conception), the entire human upper limb (including the hand) takes shape and assumes the appearance it will have in postnatal life between the fourth (fourth) and eighth (eighth) week of gestation. This means that, 56 days after conception, the human being already possesses the hands in their final form, including separation between the fingers (at the origins of its development, the upper limb resembles a paddle, with the hand representing the "extremity delegated to cleave the water).
In such a context, syndactyly is the consequence of an error during the development of the upper limbs, in the 56 days mentioned above. To be precise, the error in question is a cellular signaling error, such that proper finger separation does not take place.
In other words, it is as if the biological signal indispensable to the division of the fingers - which at the origins are effectively all joined together - failed or was not appropriate for the purpose.

Did you know that ...

The separation of the fingers and toes is the result of a cellular signal that causes apoptosis. Apoptosis is the so-called programmed cell death, a completely physiological process, carried out by the organism for specific purposes, including correct development of the anatomical parts, survival, etc.
In "apoptosis, we witness the death of" useless "cells, not essential for survival, sometimes even harmful.
Apoptosis is opposed to cellular necrosis, which is the death of a cell, resulting from pathological processes, sometimes even very serious.

Sporadic, hereditary and syndromic syndactyly

In most cases, syndactyly is the result of an isolated event, in the course of embryonic development, which alters the final formation of the hand; for these circumstances of syndactyly - identified with the term sporadic syndactyly - a precise cause is not recognizable, therefore neither genetic nor hereditary factors seem to play a role.
In the remaining clinical cases, syndactyly can correspond to:

An "inherited" anatomical abnormality (ie transmitted from one or both parents), not associated with other abnormalities or other symptoms (hereditary syndactyly);

or to:

An "anatomical anomaly inserted into" a much wider clinical picture, the result of a genetic syndrome or presumed such (syndactyly syndactyly). Genetic or presumed syndromes associated with syndactyly include: Poland syndrome, Apert syndrome and Holt-Oram syndrome.

Genes implicated in syndactyly

Molecular biologists and genetics experts have identified at least 3 chromosomes which, if mutated in certain specific portions, play a crucial role in the onset of syndactyly.
The 3 chromosomes in question are chromosome 2, chromosome 6 and chromosome 7.

Chromosome 2 has a region which, if mutated, is responsible for syndactyly between the third and fourth finger or toe.
Chromosome 6 presents an area which, if a victim of mutation, is associated with the syndactyly of the little finger of the hand with the neighboring ring finger.
Chromosome 7 has an area which, if mutated, is related to the syndactyly of all fingers or toes.

Complicated syndactyly: it is when, in addition to the union between the fingers at the level of skin, bones and cartilage, the presence of an extra finger or the absence of a finger is also added.

When to see a doctor?

Syndactyly is an "anomaly that does not go unnoticed at the time of birth. Therefore, its identification and subsequent planning of the most appropriate treatment are immediate.

Complications

If left untreated, syndactyly alters the normal growth of the fingers, causing noticeable deformities in addition to negatively affecting the function of the affected hands or feet.

A classic deformity resulting from syndactyly is the curvature of the longer finger in the direction of the shorter finger.

pathological and to outline a picture of the symptoms present.

The physical examination also allows us to establish whether the syndactyly is incomplete or complete and whether the number of toes is normal or not.

What are the next steps?

Once the presence of syndactyly has been identified, the diagnostician initiates the necessary investigations to identify the causes triggering the anatomical anomaly present.
As a rule, these investigations consist of:

An "accurate anamnesis. It is the critical study of the symptoms through specific questions (N.B: since the patient is usually a newborn, the doctor's interlocutors will be the parents), combined with an examination of family history.
Through the anamnesis, the doctor understands whether or not syndactyly is a recurrent anomaly in the patient's family; this information is important for establishing the nature of syndactyly, ie whether it is sporadic, hereditary or associated with a genetic syndrome.
An X-ray radiological examination. X-rays are used by the doctor to determine whether the fusion between the fingers also affects bone and cartilage tissues.
A genetic test. It is the DNA analysis aimed at detecting mutations in critical genes.
In a syndactyly context, it is the investigation to establish whether the present anomaly is related to some genetic syndrome.

surgical. Then, once the plaster is removed (usually this happens after a few days), temporarily apply splints to the operated fingers, waiting for complete recovery.

For obvious reasons, complete recovery from a complex syndactyly surgery (ie in the presence of a fusion between bone and cartilage tissues) takes longer than complete recovery from a "simple syndactyly operation.

WHAT IS THE BEST TIME TO PERFORM THE INTERVENTION?

Surgical treatment of syndactyly must take place at an early age.
The best time to carry out the surgery varies according to the location of the syndactyly:

If the fusion is between thumb and forefinger or between ring finger or little finger, the operation must take place by the sixth month of age.
If the fusion is between fingers other than those indicated above, the operation can also take place at 18-24 months of age.

IS ONE SURGICAL INTERVENTION SUFFICIENT?

Some cases of syndactyly in the hand require the performance of a second surgery at a more mature age. In these situations, the post-operative phase also includes a cycle of physiotherapy sessions.