Syndactyly: Causes, Symptoms & Treatment

People with syndactyly have a congenital deformity of the hands and feet. Fused fingers and toes are conspicuous. Syndactyly can occur alone or in conjunction with other hereditary diseases.

What is syndactyly?

Syndactyly is a malformation of hands or feet that occurs during the embryonic stage of development. The separation of the toes and fingers, which occurs between the 5th and 7th weeks of embryonic development, is disturbed. Syndactyly is one of the most common hand malformations, as simple syndactyly affects about one in 3000 newborns. The term comes from the Greek: “syn” means together and “dactylos” means fingers, which are consequently grown together. In extreme cases, this applies to all fingers of a hand. The third interfinger crease is most commonly affected on the hand and the second interfinger crease on the feet. Thus, individual phalanges of the toes and fingers do not divide completely. Syndactyly is relatively common. Due to the disease, the mobility of the fingers is limited. If all fingers are affected, normal gripping function is not possible. This is called spoon-hand. This malformation is often a genetic disorder (Apert syndrome). Among the malformations of the hand, it is the most common. Syndactyly is differentiated according to the degree of the affected limb:

Thus, as cutaneous syndactyly, there may be a connection of only the skin between the affected limbs. In osseous syndactyly, on the other hand, parts of the bones fuse. Separation is possible in most cases of syndactyly and is performed before the end of the 3rd year of life, if possible.

Causes

The cause of syndactyly is genetic. Affected individuals have a dominant gene that caused this hereditary disease. The frequency of inheritance is between 10 to 40 percent familial. Due to the defect, the limb segments do not separate in the intended developmental phase of the embryo. Syndactyly does not only occur as a single disease. In many cases it is an accompanying symptom of other genetic diseases. What they all have in common is that they affect the normal development of the embryo. Syndactyls are developed only to a very small extent later in life. In these cases, they are exogenous syndactyls. In most cases, they result from an injury or accidental event, as a result of which healing of the skin or bones was not or could not be properly cared for medically.

Symptoms, complaints, and signs

Syndactyly is primarily noticeable by the deformities of the hands and feet. In affected individuals, the fingers and toes are fused together, resulting in problems moving and grasping. Depending on the extent of the disease, even simple movements can no longer be performed. In the long term, syndactyly leads to considerable restrictions in everyday life. In the later course of the disease, for example, bony connections form between the fingers and toes, which are externally noticeable and restrict the joints in their ability to move. In so-called acrosyndactyly, fingers or toes of different lengths develop. Subsequently, holes form in the skin bridge, which can become inflamed. Syndactyly and acrosyndactyly mainly affect the aesthetics, although movement restrictions may also develop as the disease progresses. Especially in severe disease, there is a risk of serious complications developing as a result of the fused limbs. In the absence of treatment, fine motor skills and sense of touch increasingly deteriorate. The affected children often also suffer emotionally from the aesthetic abnormalities. Social anxiety or even depressive moods may then develop. Early surgery can completely eliminate the symptoms.

Diagnosis and course

Syndactyly can be detected after birth by visual examination. Imaging techniques are subsequently used to determine which form of syndactyly is present. In this way, the connecting bone bridges in osseous syndactyly can be determined more precisely. In most cases, syndactyly can already be detected prenatally during the screening examinations of pregnant women. This allows the child’s parents and the treating physicians to be prepared for syndactyly at an early stage.In the area of the phalanges, it is in most cases an aesthetic problem that has no influence on the development of the child. The course of syndactyly on the phalanges is different. Children need the ability to grasp in order to develop according to their age. Untreated syndactyly of the hands can lead to developmental problems.

Complications

In syndactyly, primarily the fused fingers and toes cause complications. Depending on how severe the deformity is, affected children may not be able to perform everyday tasks without outside help. As a result, affected individuals may develop much more slowly than their peers and may not become truly independent until late in life. If the child is not helped, this can lead to developmental disorders, as fine motor skills and sense of touch are not sufficiently developed. Those affected often also suffer from the cosmetic abnormalities associated with syndactyly and withdraw from social life at an early age. Teasing and bullying can also not be ruled out. Surgical treatment of the deformity can always cause complications. For example, surgical procedures occasionally result in nerve injury, infection and bleeding. Wound healing disorders and secondary bleeding can occur after surgery. Due to scarring, the aesthetic impairment may be even more noticeable than before. Finally, the prescribed medications also carry a certain risk. Especially in children, an incorrect dosage or an undetected previous illness can quickly lead to unexpected side effects or interactions.

When should you see a doctor?

Malformations or mutations in the limbs are usually diagnosed immediately during or after birth. In many cases, irregularities may already be detected in imaging studies during the prenatal period. For this reason, expectant mothers should participate in all examinations offered during pregnancy. These allow early detection and, if possible, initial treatment steps. If abnormalities have already been noticed before delivery, an inpatient birth is often recommended. The attending obstetric team independently and on their own responsibility takes over the initial examination of the offspring. In these cases, the parents do not have to become active, but they should be approachable by the attending physicians so that necessary decisions can be made as quickly as possible. In the case of a birth in a birth center or a home birth, midwives or assistants are also present. Just as in the case of a birth in a hospital, they will perform the initial examination of the child. The malformation of the fingers and toes is determined by visual contact. A doctor is then informed of the health abnormalities by the obstetricians present. Again, parents do not need to take any further action, as this is handled independently by the medical attendants. In rather rare cases, a spontaneous birth occurs in which no nursing staff is present. Immediately after the birth, a doctor should always be consulted.

Treatment and therapy

Treatment of syndactyly consists of surgical procedures to separate the fused limbs. This mainly affects the finger limbs, as the separation there goes beyond an aesthetic correction. The operation is performed at a very early stage. If the syndactyly is only cutaneous like a webbed skin, surgery is very unproblematic. It is more difficult if the fusion of the bones is so pronounced that two limbs with the same bone structure cannot be determined. During the separation operation, it must also be taken into account that the changes usually also affect the nerves and vessels (arteries and veins). Therefore, a careful separation is necessary. In the case of syndactyly of the phalanges, treatment is often waived and the decision is left to the affected person. Many people with syndactyly of the phalanges forgo having it surgically repaired altogether. They do not find the fused limbs bothersome. Depending on the degree of syndactyly, surgery may also be inadvisable, as the aesthetic impairment caused by scarring may be even more noticeable than the pre-existing deformity.

Prevention

Prevention against syndactyly is not possible.It is a genetic deformity that is already inherent in the embryo. Even with prenatal diagnosis, however, there is no reason for increased concern for the child’s parents if other diseases have been ruled out. Syndactyly on the feet is a visual impairment that has no consequences for the children. On the phalanges, surgical treatment of syndactyly is easily feasible even in infancy.

Aftercare

Aftercare is important when the fused fingers or toes have been separated by surgery. The focus here is on the bandaging technique. If the dressing turns out to be too small, there is a risk that it will be unintentionally stripped off by a child during the night. Therefore, dressings after syndactyly surgery should be large enough, which requires some effort. If the toes were separated during syndactyly surgery, the patient wears a special shoe for a period of two to three weeks. Aftercare can be provided by a resident physician who has already gained sufficient experience with this type of surgery. In most cases, however, the hospital takes over the aftercare due to the high effort involved in changing the bandages. As a rule, the bandage is worn for about two weeks after syndactyly surgery. After that, the removal of the stitches takes place. To treat the pain, the patient is given an analgesic for the first one or two days. In most cases, this is paracetamol suppositories. To combat the scars that form as a result of the surgical procedure, special scar gels are administered. They help to keep the scars as inconspicuous as possible. After a procedure to separate the toes, the use of crutches may be appropriate, which is ultimately decided by the attending physician.

What you can do yourself

Syndactyly is a congenital condition that can only be treated symptomatically. Affected individuals need the support of a specialist and, in addition, help in everyday life. If several fingers have grown together, surgery may be considered. However, the movement restrictions often remain permanently. The most important measure is to perform movement exercises regularly. If circulatory problems occur, the doctor must be consulted. If these measures do not bring improvement, it is best to talk to the doctor again. Sometimes the disorder is so severe that an improvement in the ability to move can no longer be achieved. Then supportive aids must be used to compensate for the limitations. Surgery is usually performed before the child is three years old. From then on, parents must pay careful attention to the child’s hand and finger movements and compensate for them if necessary. Particularly in the case of fingers that are not of equal length, joint deformity can be prevented by early medical treatment. The prerequisite is that the child continues to receive medical support after the procedure. It is the parents’ responsibility to monitor the course of the disease and the intake of any prescribed pain medication.