Disease Description (Causes and Symptoms)
- Definition: Congenital hand deformities refer to conditions in which the shape or structure of the hand is abnormal at birth, including polydactyly (extra fingers or toes), syndactyly (webbed fingers), clinodactyly (curved fingers), trigger finger, ectrodactyly (split hand), macrodactyly (overgrowth of a finger), and congenital constriction rings (compression bands).
- Causes and pathophysiology:
- Genetic factors (approximately 20%) and environmental factors (approximately 20%) are partially associated, while approximately 60% are reported to have an unknown cause.
- Syndactyly: Occurs due to a deficiency of the differentiation between the fingers (apoptosis) that normally takes place between the sixth and eighth weeks of pregnancy.
- Polydactyly: Occurs when digital rays duplicate or undergo excessive differentiation during finger development.
- Ectrodactyly (split hand): A complex developmental abnormality involving absence or abnormal differentiation of the central digits.
- Congenital constriction ring (constriction band around a finger): Ischemic injury caused when an intrauterine band or tissue constricts a finger.
- Main symptoms:
- An increased number of fingers (polydactyly), fusion of the skin or bones between the fingers (syndactyly)
- Flexion or deformity of a particular finger (clinodactyly, camptodactyly), trigger finger (inability to bend or straighten due to a tendon abnormality)
- V-shaped defect or partial absence of digits (ectrodactyly)
- Excessive enlargement of a finger (macrodactyly)
- Prevalence (reference):
- Congenital hand deformities overall are reported in approximately 2–4% of newborns.
- Syndactyly occurs in approximately 1 in 2,000 people, and polydactyly in approximately 1 in 400 (with differences by region and ethnicity).
Treatment Methods
- Diagnosis
- Identified through a clinical examination at birth. If necessary, hand X-rays (to check for the presence and structure of bones), ultrasound, CT, or MRI (to assess complex bone and soft-tissue structures) may be performed.
- Some deformities can be detected by prenatal ultrasound.
- After checking the family history and whether systemic deformities are present, genetic counseling may be considered.
- Surgical treatment (standard approach)
- General principles: The goals are to restore function and achieve the most natural appearance possible. In many cases, surgery under general anesthesia with hospitalization is necessary.
- Timing (recommended timing varies depending on the condition):
- Congenital constriction rings (when compression or threatened blood flow is present): Immediate surgery.
- Syndactyly involving the thumb or syndactyly with bone fusion: Surgery around 6 months of age.
- Simple syndactyly and polydactyly: Usually surgery around 12 months of age.
- Severe deformities (requiring complex ligament grafting or corrective osteotomy): Usually performed after age 5, taking the child’s cooperation and skeletal maturity into consideration.
- Multiple or complex cases require staged surgery.
- Types of surgery:
- Polydactyly: Simple excision (soft tissue only), excision followed by reconstruction (preserving bones, joints, and ligaments), or combination surgery (combining two malformed parts to create a functional hand).
- Syndactyly: Separation surgery + skin grafting (such as from the groin) and zigzag incisions to prevent contracture. Complex types require bone reconstruction.
- Clinodactyly/camptodactyly: Correction with osteotomy and ligament surgery.
- Trigger finger: Tendon release or reconstruction.
- Congenital constriction ring: Removal of the band and repair of blood vessels, lymphatic vessels, and nerves.
- Nonsurgical and supportive treatment
- Conservative observation (when symptoms are mild and there is no functional impairment)
- Orthoses, splints, and physical therapy (postoperative rehabilitation)
- Postoperative care and precautions
- Sutures are usually removed around 2 weeks after surgery; if immobilization with a cast or pins is used, it is maintained for 3–4 weeks.
- Scar management at the skin graft site (such as massage and silicone sheets), along with splinting and physical therapy to prevent contracture, is necessary.
- Because recurrent deformity may occur during growth, additional surgeries may be necessary (several procedures may be needed through adulthood).
- Risk of complications
- Wound infection, wound dehiscence, differences in skin color or texture, scar contracture, joint stiffness, sensory abnormalities, the need for repeat surgery, and deformities developing with growth.
- Prevention
- There is no clearly established method of prevention. If there is a family history, genetic counseling and prenatal testing should be considered. Avoidance of known teratogens during pregnancy is recommended.
Outpatient Visit Checklist (Items to Bring and Visit Preparation)
- Items to prepare
- List of currently used medications and supplements (including those used for the baby or during breastfeeding)
- Birth-related records (if there were prenatal ultrasound findings, bring the image files or records)
- Previous test results (X-rays, ultrasound, etc.) and surgical history (including surgical records, if applicable)
- Records of symptom changes: difficulties using the hand, limitations in daily activities, pain, redness, or signs suggestive of necrosis
- Family history: Similar deformities or a history of genetic disease
- The baby’s growth and developmental status, and photographs (photos taken from several angles can help assess the appearance)
- What the medical team will check during the outpatient visit
- The hand’s shape, movement, sensation, and blood flow; whether the condition is bilateral; and whether associated deformities are present in the upper or lower limbs or trunk
- Whether additional imaging tests, such as X-rays, are needed
Examples of General Questions to Ask the Doctor
- What is the exact diagnosis of this deformity (type and severity)?
- How will this condition affect the child’s hand function (grasping, gripping, and fine motor skills)?
- Is surgery recommended? What is the reason for the recommendation, and when should it be performed?
- What are the goals of surgery and the expected results (functional and cosmetic)?
- What risks and complications are associated with surgery? How likely is repeat surgery to be needed?
- How will rehabilitation proceed after surgery (duration and need for physical therapy)?
- If a genetic cause is possible, is genetic counseling or additional testing necessary?
- What is the long-term prognosis? Will additional treatment be needed through adulthood?
Examples of Condition-Specific Questions
- Regarding syndactyly (webbed fingers)
- Is this syndactyly a simple type in which only the skin is joined, or a complex type in which the bones are also connected? If the bones are fused, what procedures are expected during surgery?
- Skin grafting is needed during surgery. How can differences in the graft site, scar, color, and texture be minimized and managed?
- Regarding polydactyly (extra finger)
- When is the best time to remove the extra finger? Will simple excision be sufficient, or might reconstruction (correction of the joint and ligaments) also be necessary?
- What function and appearance can be expected for the remaining finger after removal, particularly on the thumb side?
(If necessary, bringing test results and photographs may allow the diagnosis and surgical plan to be explained more accurately.)