The deformity of multiple fingers and toes is mostly unilateral, and only about 10% are involved bilaterally. The exact cause of compound bunion is unknown, and most of them are disseminated, suggesting that the disease is related to environmental factors and not much to genetic factors. For example, the mother is affected by viral infections, drugs, radiation and other environmental factors during the early 4-8 weeks of pregnancy, when the embryonic limb buds are differentiated, resulting in impaired finger differentiation and disease classification.
The Wassel typing proposed in 1969 classified compound thumb deformity into 7 types according to the severity of polydactyly, which is still widely used. It is generally believed that polydactyly of the little finger is genetically determined and can also be classified into three types according to the severity of repetition.
Clinical presentation
Children are found to have extra fingers at birth, and the type and severity of the deformity vary, with some being connected to the normal finger only by a narrow vascular nerve-encapsulated dermatome;
Some have nails, bones and joints, tendons and vascular nerve bundles, and have some finger movement and sensory function, making surgical selection difficult;
In some cases, the deformity is as severe as “crab pincer”, with poorly developed fingers, small and deviated fingers, which seriously affects the appearance and function of the hand.
In addition to the physiological effects, children and parents often have psychological problems, and psychological concerns can affect the child’s psychological development, learning and social life, and even affect future employment, work and marriage.
Associated malformations
The most common are associated with cardiovascular, neurological or urinary malformations, such as congenital heart disease, congenital cerebral dysplasia, etc. A comprehensive and systematic physical examination should be conducted for children with suspected malformations.
Disease diagnosis
The diagnosis of congenital polydactyly can be made based on the medical history and clinical examination. The auxiliary examinations are mainly X-ray to clarify the type of polydactyly and the growth of bones and joints to provide a basis for the choice of treatment plan.
Treatment principles
If there is a difference in the development of the two thumbs, the thumb with poor appearance, lack of function or three phalanges should be removed. If there is no significant difference in the appearance and function of the two thumbs, resection of the lateral polydactyly is often chosen.
If the polydactyly occurs at the level of the articulation, in addition to the polydactyly resection, a portion of the corresponding proximal articular cartilage surface should be resected and blocked to effectively prevent recurrence of the polydactyly, and the joint capsule and collateral ligaments should be repaired, and the tendons should be transferred and sutured.
If the thumb recurrence occurs at the level of the diaphysis combined with angular deformity, the polydactyly is resected with osteotomy orthopedic correction of the force line and internal fixation of the finger bone with steel pins. For poorly developed, severely deformed (crab pincer) compound thumb, a modified Bilhaut procedure is performed at an early stage (8-12 months) to replace the skeletal consolidation with soft tissue consolidation to reduce complications such as osteochondrosis and joint ankylosis, and to maximize the reconstruction of an aesthetic and functional thumb through tendon transfer and soft tissue narrowing on the convex side. Residual deformities can be further corrected by wearing orthopedic braces or by further bony surgery at the age of 3-6 years.
Surgery for polydactyly is generally recommended before toddlerhood, i.e., 9-12 months after birth, otherwise the abnormal stress area will be formed on the sole of the foot and will be removed or altered after surgery, thus affecting gait.
Surgical treatment
After the discovery of the disorder, the doctor and patient will communicate and develop a reasonable and personalized treatment plan according to the condition.
Treatment for congenital polydactyly varies depending on the extent of the disease. Simple dermatomal polydactyly can be surgically removed in the first month of life or postponed until the third month of life if anesthesia is a safety concern.
For complex polydactyly with articulated skeletal connections, surgery may be performed between 6 months and 3 years of age. Before surgery, the level of repetition of the polydactyly must be evaluated and typed; the degree of development of each part, the stability and mobility of the joint, the degree of deviation of the skeletal axis, and the severity of the finger deformity must also be evaluated.
Disease care
After polydactyly surgery, it is necessary to keep the wound dressing clean and tidy to prevent wound infection; to strengthen the child’s nutrition, to eat more high-protein food, to promote wound healing, to use appropriate drugs to inhibit scar formation, and to give the child as beautiful and functional hands and feet as possible.
Disease prevention
Strengthen the health care and nutrition during pregnancy, 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.
Once a child is found to have such a problem at birth, parents need to face it correctly. They should not take it lightly, as some parents do, because they use threads or hair strands at home to tie the multiple fingers of the skin type, resulting in finger necrosis, wound infection and septicemia, which makes further treatment difficult; nor should they be overly nervous and try to solve the problem immediately. Because there are certain risks associated with neonatal anesthesia, you can wait until the child is a month old to get a diagnosis from an experienced doctor to clarify the type and severity of the deformity in order to decide the best time and treatment plan. There are various types of polydactyly and toe deformities and different treatment methods. We hope that each child can receive reasonable and timely treatment and that each child can have a perfect life. Deformities. Exceptions are when duplicated bunions are accompanied by triple bunions, some of which are autosomal dominant.