—It is particularly in the skull that the manifestations of rickets are most common, the bone becoming unduly thick and the general shape being changed. Usually there is a flattened vertex with delayed ossification, with an abnormally firm union along the suture lines. In spite of these changes, the bone often becomes affected by pressure to such an extent that a rachitic or hydrocephalic child, confined to bed and moving little or not at all, will develop a skull showing the effect of such pressure. Many rachitic skulls show areas of atrophic thinning, dispersed irregularly, while the inner surface may show the markings of the convolutions impressed upon it by the softness of the bone ([Fig. 368]). (See [Rachitis].)
Fig. 368
Craniotabes (rachitis). (Bruns.)
SURGICAL AFFECTIONS OF THE CRANIAL BONES.
The acute affections of bones have been considered in Chapter XXXII. Acute periostitis is, in the main, due either to syphilis or to an infection following injury. In the latter case it proceeds from the margin of the wound, and may spread to a considerable distance. It is in some instances secondary to deeper infection extending from the middle ear, and then is found posteriorly to the ear and externally to the mastoid cells. Congenital openings or defects of the sutures about the mastoid seem to have much to do with the travelling of infectious lesions in these localities.
Fig. 369
Osteoma of skull. (Mudd.)
Fig. 370