1.Overview.
Congenital syndactyly is a congenital deformity of the hand and foot second only to polydactyly, in which two or more fingers and toes are congenitally pathologically connected in part or in whole tissue components. The incidence is 0.33-0.5 per 1,000, half of the children have bilateral syndactyly, with a male to female ratio of 3:1. Syndactyly is most common in the middle ring finger (50%), followed by the ring little finger (15%) and the thumb and index finger (5%). Some severe multi-site syndactyly is a manifestation of systemic diseases in the hands and feet, such as Apert syndrome and Poland syndrome, so some of them are also associated with other systemic deformities such as cardiovascular, neurological or urological deformities. Xu Yunlan, Department of Orthopedics, Shanghai Children’s Medical Center
2. Etiology and classification.
The cause is mainly embryonic developmental abnormality, and it is generally believed that the origin of the syndactyly is due to the incomplete separation of the distal palmar plate and the fingers during the 7th-8th week of pregnancy. A few of them are hereditary, most of them are autosomal dominant and a few are autosomal recessive or sex chromosome inherited. According to the degree of juxtaposition, it can be divided into: complete juxtaposition and incomplete juxtaposition. According to the structure of the juxtaposed tissues, they can be divided into: simple juxtaposition and complex juxtaposition. The former has only skin and soft tissue juxtaposition, while the latter has bony fusion.
3. Symptoms and hazards.
The child is found to have merged fingers and toes at birth. There are various types and severity of deformities: some fingers and toes are connected by webbing only; some two fingers and toes including finger and toe nails are completely merged, and the fingers and toes are deflected and cannot be straightened; even multiple fingers and toes are merged, which seriously affects the function. In addition to the physical effects, children and parents often have psychological problems, psychological concerns can affect the child’s psychological development, and even affect learning and future employment and life.
4. Common concomitant deformities.
The most common are concomitant thoracic deformities, cardiovascular, neurological or urological deformities, such as congenital heart disease, congenital cerebral dysplasia, etc. A comprehensive and systematic physical examination should be conducted for children with suspicion.
5.Diagnosis.
Congenital syndactyly can be clearly diagnosed based on medical history and clinical physical examination. Auxiliary examinations are mainly X-ray radiographs to clarify the type of syndactyly and the growth of bones and joints to provide a basis for the choice of treatment plan.
6.Treatment modalities and indications.
After the discovery of the disorder, we will seek medical treatment in time, and make a reasonable and personalized treatment plan according to the condition after doctor-patient communication. In general, it is not enough to cut the two combined fingers and toes, but to design finger webs, toe webs and special “Z” flaps to prevent the contraction of scars during the growth and development. In most of the cases, local implantation is required, and the donor area is usually the lower abdomen or thigh, and the inner side of the upper arm. Separation surgery requires protection of the blood vessels and nerves of the separated fingers and toes; very careful removal of the grafted skin and grafting sutures are required, which is a very delicate operation and takes a long time. It usually needs to be performed by a specialist with considerable experience, because once the first treatment is unsatisfactory, subsequent revision surgery is quite difficult.
Simple incomplete skin merging fingers and toes, which generally do not affect the growth and development of the fingers and toes, can wait until the child is 3 years old to have the surgery, which effectively reduces the possibility of recurrence in the webbing area. In recent years, there has been a trend to advance the age of surgery, with the earliest reported in the foreign literature being as early as 18 months of age of the child. If the fingers of different sizes are fully involved and the larger fingers are deviated and limited in extension, it is best to separate them early, before the child is 12 months old, to control and correct the deviation. When more than one finger is involved, especially the thumb, the marginal finger should be released first, and the thumb and index finger should be separated at the age of 6 months to facilitate the development of the basic palmar function of the hand. Later, the other syndactyly should be separated. Complex types of bony syndactyly are more difficult to treat clinically and have more complications. After separation of the fingers and toes, there is often deviation and flexion of the fingers and toes and partial dysfunction, which often requires multiple surgical procedures such as skin grafting and osteotomy to repair the fingers and toes.
According to our experience, it is very important that the implant surgery should not be performed in the hot summer.
7.Post-operative precautions.
It is necessary to keep the wound dressing clean and tidy to prevent wound infection after syndactyly; strengthen the nutrition of the children and consume more high-protein food to promote wound healing, and generally change the wound medication in 10-14 days after surgery, and remove the stitches in 2-3 weeks. Appropriate selection of drugs to inhibit scar formation, as far as possible to give children beautiful, functional hands and feet.
8. Prevention.
Strengthen pregnancy health care and nutrition, avoid respiratory infections, gastrointestinal infections, rubella, measles, chicken pox, mumps and other viral infections during pregnancy, and avoid exposure to radiation, drugs and other possible embryonic teratogenic factors.
9.Summary.
The syndactyly and toe deformity are common congenital malformations in children. Once a child is found to be born with such a problem, parents need to face it correctly and not to be overly nervous and try to solve the problem immediately. On the one hand, there is a certain risk of anesthesia in newborns; on the other hand, children are in the process of continuous growth and development, and the reconstructed webbing area of the fingers and toes will be extended upward with the growth of the fingers and toes after the separation of the syndactyly. Therefore, parents can wait until the child is one month old to get a diagnosis from an experienced doctor to determine the type and severity of the deformity and to decide the best time and treatment plan.