[Fascination of the hand and wrist].

By 250 million years ago, the five-finger digit is established. In developmental terms, the human hand is both specialized and primitive. Man's hand is not a unique structure, it is only the way in which it is used that sets it apart from the other animals. Its value seems therefore to be correlated with the development of brain. The fact that skin and nervous system share the same ectoblastic origin may strengthen the symbiotic effect related to brain development. Since the wrist sustains and enables most of the capabilities of the hand, a deterioration of its function may give rise to challenging diagnostic problems. Therefore a classification of wrist disabilities in five main groups may be helpful in daily practice. An ulnar translocation, a SL-dissociation, a LT-disruption or a carpal collapse may be clearly diagnosed. When no clear pathology can be demonstrated, the physician is faced with the so-called normal group. In those cases a ganglion or an osteonecrosis on onset may explain the pain. In any case however, the physician has to recall the central and physiological aspect of the hand, an organ which has become the symbol of man and power.