Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery
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The discovery of a craniocervical junction malformation requires management in three steps: (1) The patterns must be recognized using tomographic measurements (Chamberlain's line, Wackenheim's line). Dynamic flexion-extension studies are necessary to assess stability or instability. Stable patterns range from platybasia to basilar invagination, with gradual deformation, and are frequently associated with Chiari malformation. ⋯ Both static and dynamic MRI scans must be performed; in this way identification of the neural abnormalities (hydromyelia, Chiari, etc.) and of the osseous compression is possible. (3) The most appropriate operative procedure must be selected: stable platybasia with a nervous compression by Chiari is cured only by posterior decompression; odontoid instability is cured by reduction and posterior fixation, using hooks and autologous bone grafts on the posterior arches of C-1 and C-2. Sometimes a transarticular screw fixation of C1-2 is necessary if there is a defect on the C-1 posterior arch. Craniocervical dislocations with assimilation of the atlas require posterior occipito-vertebral bony fixation with grafts and external halo immobilization or internal fixation with hooks or screws, with anterior transoral decompression in a second step.
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Skull base surgery is a recent development in our history, in as much as most of the surgical techniques involved have been described within the last century. To provide an historical prospective the author reviews the development of this specialty, arbitrarily dating its beginning some five centuries ago with the work of Leonardo da Vinci. By picking this period we include the origin of scientific anatomy and personages interested in developing new ideas and concepts who were able to leave the stagnant period of the Middle Ages behind. ⋯ Harvey Cushing was to introduce this concept in the first decade of the last century. This survey traces the origins of modern skull base surgery from its antecedents in the Renaissance to the beginning of this century. A paper of this length can only provide a sampling of themes and personalities; nevertheless, it will give the reader an impressive overview of how far we have come and some ideas of what the future holds.