What are Congenital limb defects and deformities?
Congenital limb defects occur when a portion or the entire upper or lower limb fails to form normally or does not form when the baby is developing in the uterus. These deformities can be particularly disabling as the hands are important for the child for its interaction. It should be treated at an early stage before the problem becomes severe.
Some of the common pediatric hand deformities include:
- Radial and ulnar club hand deformity: This type of deformity involves all the tissues resulting in a short thumb, or complete absence of the thumb, and underdeveloped muscles and ulnar bone.
- Syndactyly: It is the most common deformity in which two or more fingers are fused together. Simple syndactyly involves fusion of only the soft tissues of fingers whereas complex syndactyly involves fusion of both soft tissues and bones of the fingers.
- Contractures: Contractures may result by improper differentiation of cells which may cause abnormal pulling of the digits as in congenital trigger thumb where the child may not be able to extend the thumb straight.
- Duplication: It is the abnormality where a child will have extra digits in the hand. The condition is called polydactyly and in many cases the extra digit would be the little finger.
- Overgrowth or macrodactyly: It is the excessive growth of a digit causing abnormally large digit. Macrodactyly is a rare condition and most commonly affects the index finger.
- Undergrowth or brachydactyly: It is the condition of underdevelopment of fingers or thumbs and may present with small digit which may be because of missing muscles, underdeveloped or missing bones, and complete absence of a digit.
- Constriction ring syndrome: The abnormality occurs because of a constricting band of tissue around a finger or arm that interrupts the blood flow to the digit and the normal growth of the tissues. It is often associated with other congenital abnormalities such as clubfoot, cleft lip, cleft palate, or other craniofacial anomalies.
What is Congenital limb Surgery?
- Congenital limb anomalies require surgical intervention. Full-term infants can be scheduled for elective surgical procedures as early as 5 or 6 months of age.
- Surgery before this age can increase anesthetic risks. Prior to that time, there is generally no intervention necessary if there are no problems.
The parents are instructed to bathe the patient on the morning of surgery, with particular instructions to wash the hands and the groin region where the skin graft will be harvested.
What to expect during surgery
- Your child’s surgery will be based on which digits are joined and how complex the connection is. If only two digits are joined and they are joined only by skin, the surgery will be simpler. If more digits are joined or the digits are joined at the bone, the surgery will be more complex. In any case, it is often done as day surgery.
- The basic method for the surgery is to make zigzag cuts (incisions) between the digits to divide them. The zigzag shape gives the surgeon pointed flaps of skin to wrap around each digit. This method helps prevent scars that could restrict growth later.
- Near the base of the digits, the surgeon will cut another flap of skin that gets folded over to make a typical web between the digits. The surgeon will sews all the flaps in place.
- Most children need skin grafts to cover the digits completely after they are divided. The zigzag method reduces the need for skin grafts. But sometimes the flaps are not big enough. The surgeon takes a small patch of skin, usually from the child’s forearm or their belly near their hipbone, to close up the area around the digits.
- After surgery, your child will need to wear a cast. The surgeon will want your child to come back for follow-up visits to make sure they are healing well.
- At a follow-up visit, the cast will be removed, and an occupational therapist will fit your child with a splint. This helps prevent scarring and shortening of tissue (contractures).
- Some children who have extensive surgery, cutting through many tissues, may have occupational therapy to help with swelling, scarring and stiffness.
Risks and Limitations
- Most surgeries are uneventful and the child does well with a satisfactory appearance after surgery and excellent function.
- Infection is a risk with any surgery. Sometimes a low grade infection can threaten skin grafts.
- Skin grafts and flaps may not survive after surgery. This complication is very rare.
- Web creep is perhaps the most notable risk. Web creep is scarring in the commissure between the fingers that lead to a partial “recurrence” of syndactyly.
- About 1 out of 3 children will need a second surgery. For some types of syndactyly, that number is higher.