Upper limb deficiencies may be due to malformations or disruptions, such as amniotic bands, from trauma, or as a result from resections of malignant tumors. Limb deficiencies are most common in the lower limb and in boys.
Vascular ingrowth is needed to supply the progress zone. In the unifying theory of subclavian artery supply disruption sequence, the type of deformity depends upon the timing of the disruption. These defects are referred to as symbrachydactyly.
The symbrachydactyly is a spectrum including the most common type of dysplasias.
Short finger form may be associated with Poland anomaly.
Cleft form previously called atypical cleft hand.
Monodactylous (thumb) form The thumb is the best preserved digit.
Peromelic–transverse arrest form This may occur at any level from shoulder to wrist. The feature that is always present is the nubbins at the end of the limb.
Although the diagnosis can usually be made by physical examination, obtain radiographs to document and classify the deficiency.
Screening examination is necessary to identify other abnormalities such as radial head dislocations or radioulnar synostosis.
Family situation should be evaluated carefully. Make certain that counseling is available for parents who are having difficulty dealing with the grief and guilt common in parents of limb-deficient children. Make a special effort to develop a warm and supportive relationship with the family because management is often difficult. Good rapport improves the child’s compliance with treatment and the parents’ acceptance of recommendations for management.
The following principles may be helpful in planning management.
Early prosthetics fitting is controversial Some physicians believe that covering the limb with a prosthesis prevents sensory feedback and slows development of bimanual function. Others recommend the fitting of a passive prosthesis between 3 and 6 months of age to promote the development of a more normal self-image by the infant. Most children reject prostheses.
First prosthesis is usually passive Convert to an active prosthesis based on the infant’s developmental age.
Myoelectric power is inherently attractive to parents. Because these electrically powered limbs are expensive and difficult to maintain, long-term acceptance is poorer than for the simpler, body-powered prostheses.
Congenital and acquired amputations are different Congenital amputees have normal sensation at the end of the limb, and are not troubled by overgrowth, scars or pain, in contrast to those with acquired forms. Congenital amputees also develop better techniques of compensation.
Modify prosthesis to facilitate activities of daily living. Make available an experienced occupational therapist to access the child’s needs and make recommendations for modifications that enhance self care.
Family support groups are extremely valuable for both the parents and the child. Most childhood amputee clinics have ready access to these support groups and can help families make the necessary contacts.
Acceptance is usually less for upper than for lower limb prostheses. The lack of sensibility and fine movement control makes upper limb prostheses less useful than those for the lower limb. Children are most likely to accept an upper limb prosthesis when a specific functional need is recognized. This awareness usually occurs at about 8 years of age.
Bilateral deficiencies Rarely is prosthetic replacement useful or acceptable.
Most successful fittings are for children with proximal transverse forearm deficiencies.
Allow child natural adaptations Such adaptations are usually practical, effective, and energy efficient.
Replace prosthesis when destroyed, if it causes discomfort, or if it becomes suboptimal for function.
Discarding of prosthetics is most common when deficiencies are extensive, prosthetic devices are complex in design, and natural adaptations without a prosthesis are effective.
Procedures have limited indications.
Revisions for overgrowth may be necessary in both congenital and acquired transdiaphyseal amputations.
Krukenberg procedure This reconstruction separates the radius and ulna to allow grasp with sensibility. The outcome is usually functionally good but cosmetically poor. The procedure is appropriate for blind patients with acquired amputations who cannot visually position items in their prosthetic hands or hooks.
Terminal devices Options include several alternatives.
CAPP (child amputee prosthetic project) includes a closing spring and a frictional resilient covering that enhances control.
Hooks with elastic closures and plastic covering are durable and can be fitted with body-powered opening mechanisms.
Cosmetic hands may be passive, body-powered, or myoelectrically controlled.
Powering devices include several options:
Body power is commonly used for both opening of a terminal device and elbow flexion.
Myoelectric power may be provided by single or double electrodes placed over flexor or extensor muscles. Single controls are usually applied during the second year with sensors placed over extensor muscles to activate the opening device. The terminal device stays open as long as the muscle is contracted. A second sensor over the flexors may be applied about age 3 for active flexion. These fittings are experimental but children have a lower dropout rate as compared with adults.
Cosmetic passive hand is a commonly selected option due to its cosmetic advantage and simplicity.
Provide options Consider providing the child with a variety of prosthetic options to help with normal activities. About half of children use multiple prostheses based on the situation.