Growing skull fracture of childhood with reference to the importance of the brain injury and its pathogenetic consideration.

It is recognized that the presence of a dural tear is essential in the development of a growing skull fracture. We present nine cases of growing skull fracture, stressing the importance of parenchymal injury beneath the skull and dural defects as pathogenic factors, and two cases which showed pathological conditions similar to those of growing skull fracture. According to our clinicla analysis, all of these cases followed head trauma in the first year of life. The area of cranial defect varied in size among the individual cases but was progressive in all instances. Convulsions were the most frequent symptom. With both radiologicla examinations and operative findings, it is recognized that dural tears and local cerebral injury are usually severe, and various localized ventricular enlargements are always found beneath the fracture. In many cases fibrous granulation was found filling in the bone defect and adhering to the contused cortex. The mechanism of the enlarged bone defect can be explained by classifying the lesions into three groups according to the type of tissue present: (1) granulation type; (2) cyst type, and (3) mixed type. Each type prevents the bone edge from spreading out, offering a suitable means to transmit mechanical pulsations of brain and cerebrospinla fluid. The formation of granulation tissue and dense scarring is an important factor in the growing skull fracture.