A six-year-old girl with congenital sensory neuropathy with anhidrosis (CSNA) presented with bilateral hip dysplasia and subluxation on the right side. Conservative treatment of the hips by closed reduction and a plaster cast was unsuccessful. When aged seven years the patient had an intertrochanteric varus rotation osteotomy on the right side, but subluxation was again evident after five months. A Salter-type pelvic osteotomy was carried out followed by immobilisation, but one year later subluxation was present in the right hip and dislocation in the left. At the age of nine years, the right femoral head resembled a Charcot joint, although walking ability was preserved. In patients with CSNA, surgery may not always be advisable.
The pathogenesis of longitudinal reduction deformities of the limbs, or dysmelia, is still a matter of debate. Their morphological pattern was defined from a large collection of radiographs of children with dysmelia following the thalidomide disaster. We compared radiographs of 378 of these limbs with the sclerotomes which are areas of segmental sensory innervation of the limb skeleton defined by the radiation of referred pain. The pattern of dysmelia matched the sclerotomes closely in 279 limbs (73.5%). The principles of skeletal reduction in dysmelia are explained by the arrangement of the sclerotomes. The congruence between two separate and independent data sets shows that both patterns are expressions of the underlying segmental sensory innervation of the skeleton, and that the sensory nervous system is involved in the process of limb morphogenesis and teratogenesis.
A classification of a group of malformations of the extremities is given and an underlying common pattern is developed from a survey of 693 deformed limbs. It is characterised by a certain reduction tendency of the affected bones and the malformed extremity, an axis of malformation and an interdependence between the proximal and peripheral parts of the deformed limbs. The group, called dysmelia, has a common morphology, but morphologically identical types have been seen caused by thalidomide and as hereditary or sporadic cases. An attempt has been made not only to name and classify these deformities but also to clarify the underlying principles of their morphology. This will enable the teratologist to see the pattern of these malformations in comparison with that of normal development of the limbs and of experimentally induced limb defects.
