Diagnosis.—When the instrument impinges on the head obliquely, after piercing the scalp it may pass for some distance under it before perforating the skull, so that on its withdrawal a valvular wound is left, and at first sight it appears that only the scalp is involved. Sometimes a foreign body left in the gap so fills it up that it is difficult to detect the fracture with a probe or even with the finger. In all doubtful cases the scalp wound should be sufficiently enlarged to exclude such errors. We have known of a case of a man who died of meningitis resulting from a punctured fracture of the vault caused by the spoke of an umbrella, the fracture having escaped recognition until the meningeal symptoms developed.
Treatment.—The scalp wound must be purified, being opened up as far as necessary for this purpose. The infected portion of bone should be removed to render possible the purification of the membranes and brain, and to permit of drainage.
Depressed and Comminuted Fractures.—As these varieties almost always occur in combination, they are best considered together. The terms “indentation fracture,” “gutter fracture,” “pond fracture,” have been applied to different forms of depressed fracture, according to the degree of damage to the bone and the disposition of the fragments ([Figs. 188], [189], [190]). These fractures may be simple or compound.
Fig. 188.—Depressed Fracture of Frontal Bones—involving the air sinus on both sides—with a fissured fracture radiating from it.
(From Professor Harvey Littlejohn's collection.)
Fig. 189.—Depressed and Comminuted Fracture of Right Parietal Bone: Pond Fracture. The patient sustained the injury twenty years before death.