Finger deformities in children can be grouped into general categories. Finger deformities are often genetic, and the genes responsible for preaxial polydactyly, cleft hand and foot malformations, synpolydactyly, and types of brachydactyly have recently been identified.
Hypoplasia of the Digits
Types of hypoplasia of the digits are numerous and varied. This makes it necessary to individualize management with the objective of improving function, sensibility, and mobility. Digital reconstruction by toe-to-finger transplants or elongation of digits are examples of extraordinary reconstructive procedures.
Polydactyly, or duplication, a failure in segmentation, accounts for 5–10% of all hand deformities. Polydactyly can be classified by the tissue involved or by location. The locations include radial, central, and ulnar categories. Central and ulnar polydactylies involve the fingers. Remove or ligate simple duplications in early infancy. Delay correction of complex duplications until late in the first year.
The syndactyly may be complete or partial. It is described as simple if only the soft tissues are involved, or complex if bones are fused. Correct by operative separation and full-thickness skin grafting. This correction is technically demanding, and revision rates are high if attention to detail is not meticulous.
Trigger fingers are usually due to congenital abnormalities of the flexor mechanism. Simple release of the pulley is often ineffective, and exploration and adjustment of the flexor mechanism may be necessary.
Bent or curved fingers occur in the frontal or sagittal planes. Except for camptodactyly, all have an underlying bony deformity. Many are associated with a variety of generalized disorders.
Correct by performing a physiolysis of a delta phalanx or a wedge osteotomy of the trapezoidal phalanx when sufficiently large in mid childhood. Delay correction until late childhood or early adolescence to reduce the risk of recurrent deformity.
Camptodactyly is the common flexion deformity of the fingers that is divided into infantile and adolescent forms. The deformity is often progressive. Disability is usually mild. Treatment includes splinting and, rarely, operative correction.
Delta phalanx is an abnormal interposed triangular ossicle in the finger, producing an angulatory deformity. Correct by osteotomy, or resection of the bridging physis. Following physeal resection, fill the defect with autogenous fat to prevent recurrence.
Kirner deformity This is a progressive curving of the terminal phalanx of the little finger. The deformity is characteristic in appearance, usually causes little disability. If the lesion is painful, immobilize the finger with a splint. Rarely is the deformity severe enough to require correction by a phalangeal osteotomy.
Finger lengthening procedures are rarely appropriate.
Fusions may involve the proximal or distal interphalangeal joints. The deformities are often inherited and are varied in pattern. Sometimes an osteotomy is necessary to reposition the finger in a more functional position.
Finger osteotomies are often appropriate to correct deformity and to position the finger in a more functional position. Fix most finger osteotomies with K wires. Osteotomies are commonly performed.
Toe-to-finger transfers Toe transfers are the most effective means of improving grip function of the hand in children with absent digits. Second toe transfer is usually made. Operative indications are rare.
Finger lengthening of up to 10 mm in single-stage and 30 mm by gradual distraction may be achieved. Metacarpal lengthening improves pinch function in children with either transverse deficiency or constriction band syndromes. Finger lengthening may improve appearance in children with brachydactyly. These lengthening procedures are only rarely indicated. The decision involves a careful assessment, considering the risks and the aesthetic and functional benefits.