Constriction bands are more likely to involve the distal part of the limb, especially the hand and foot. The central digits are usually affected; severe acrosyndactyly is rare in the thumb. A paralytic clubfoot deformity due to compression neuropathy of the peroneal nerve caused by a deep, below-knee constriction band has been described. Deformities associated with constriction band syndrome include cleft lip and cleft palate, heart anomalies, meningocele, hemangioma, and congenital clubfoot.

Annular grooves caused by constriction bands are released by Z-plasties. If parts are missing, the surgical or prosthetic treatment depends on the level of the amputation.

VII. Generalized Skeletal Abnormalities

Hand defects may be manifestations of a generalized skeletal defect, such as dyschondroplasia, achondroplasia (see Plates 4-1 to 4-3), Marfan syndrome (with arachnodactyly), and diastrophic dwarfism (see Plate 4-6). In this category, the hand deformities are unique to each syndrome.

IMPROVING FUNCTION IN PATIENTS

Although a malformed limb may not look normal, with proper rehabilitation it can sometimes achieve almost normal function in certain prehensile patterns. Prehension requires two mobile opposing parts that either diametrically oppose each other or can be adducted parallel to each other. If these parts have normal sensation and if the proximal joints can place the hand or foot in the desired position, functional activities can be performed with some skill.

Foot Prehension in Amelia. In children with bilateral absence of the upper limbs and functional lower limbs, a bilateral upper limb prosthesis allows prehension and is useful in social situations. However, prehension with it lacks sensory feedback and is awkward and imprecise, and foot function should be encouraged. Young children with amelia become amazingly adept at using their feet, learning early to explore their environment by touching and manipulating objects (see Plate 4-38). In early childhood, they begin to use their feet for prehension with sensation. They develop extraordinary flexibility in the hips and legs that allows them to position their feet for functions around the head. Eventually, even small objects may be handled with precision. Some older patients learn to put on their prosthesis, take care of personal hygiene, eat, and even drive a car with their feet. Special devices extend their skills in dressing, toilet care, and other activities.