Polydactyly of the Hands and Feet

This 2-week-old boy was born with well-formed extra digits on both hands and feet. The extra digits on the hands were attached by a narrow band of tissue to the lateral base of each little finger, and there were 6 toes on each foot. Radiographs showed synostoses of the fifth and sixth metatarsals of both feet. No other anomaly was apparent. The father’s paternal grandfather, greatgrandfather, and cousin also had extra digits at birth; however, none had involvement of all 4 extremities. The baby was referred to a pediatric orthopedic surgeon for treatment.

Polydactyly may be total or rudimentary and is divided into 3 subtypes:
•Ulnar or postaxial (affecting the little finger or little toe).
•Radial or preaxial (affecting the thumb or great toe).
•Central (between adjacent fingers or toes).

Ulnar polydactyly is a common autosomal recessive condition in African Americans. It is 8 to 10 times less common in whites, in whom it is more likely to be part of a syndrome.¹ Associated syndromes include Carpenter syndrome, Ellis–van Creveld syndrome, Meckel-Gruber syndrome, polysyndactyly, trisomy 13 syndrome, orofaciodigital syndrome, and Rubinstein-Taybi syndrome.² Radial polydactyly is more commonly sporadic.

Polydactyly is the most common congenital anomaly of the toes, with an incidence of 2 per 1000 births. An extra toe is more common in girls and in African Americans. Polydactyly of the foot is bilateral in 50% of affected persons and is associated with finger polydactyly in 33%.²

Radiographs may be useful in evaluating the anomaly and in defining the presence of bone abnormalities or articulations. The findings can help formulate the appropriate surgical procedure and/or reconstruction necessary for the patient.

Treatment of polydactyly is indicated for cosmesis and for psychosocial reasons. In patients with extra toes, depending on the extent of the toes’ development and attachment, treatment may be required for proper fitting of standard shoes.

An extra digit on the little finger is commonly attached by a thin stalk and can be easily treated in the office immediately following birth or anytime thereafter. Treatment may be accomplished by fine suture ligation (eg, with 4-0 black silk) at the base of the extra digit. Most other extra digits, including those of the thumb and toes, are complex and require referral to a pediatric orthopedist and/or plastic surgeon for reconstruction. Surgery is usually done between 9 and 12 months of age, which is early enough to have minimal impact on the infant and late enough for the tissue planes to be better developed.
 

References:

REFERENCES:

1.

Benson MR, Fixsen JA, Macnicol MF, Parsch K, eds.

Children’s Orthopaedics and Fractures.

2nd ed. London: Churchill Livingstone; 2002:311.

2.

Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds.

Nelson Textbook of Pediatrics.

18th ed. Philadelphia: Saunders Elsevier; 2007:2780, 2829.