Whatever may be the wisdom of operating in other cases where there is room for doubt as to the proper course there rarely is uncertainty as to the proper treatment of gunshot wounds of the skull, which should be invariably subjected to operation.
It will thus be seen that fractures of the skull may be simple or compound, or complicated with other injuries, or depressed, without any reference to whether they are simple fissures or more extensive injuries. On the other hand, depressed and comminuted fractures may occur without being compound in a surgical sense, and with each one of these injuries there may be accompanying disturbance of the brain of any degree of severity, from the mildest concussion or shock up to rapidly fatal compression. Any imaginable complication of these head injuries is not beyond the bounds of possibility.
The essential features in explaining the mechanism of fractures of the vertex are the area involved and the violence of the impact. The skull is often surprisingly elastic, even in the oldest individuals, and fractures occur ordinarily when the natural limits of elasticity have been exceeded and bone cohesion overcome. Children particularly suffer from depression without fracture, which formerly was never operated upon, but which is now regarded as requiring operation. On the other hand, certain skulls are abnormally fragile (see [Fragility of the Bones], [Chapter XXXII]), and among the insane may be found so porous and yielding as to be easily pressed out of shape. In injuries of slight extent it is sufficient that the skull be regarded as composed of an elastic substance, while for injuries produced by greater violence the skull is to be considered rather as a globe or arch possessed of high resistance and elasticity, whose shape will probably yield more or less before a fracture results. Much may be learned from such experiments as those of Félizet, who filled skulls with paraffin and dropped them from varying heights, and then divided the bone, to note in numerous instances that, although the bone had not been fractured, it had yielded at the point of impact to a degree producing a marked depression in the paraffin beneath. After various injuries, especially to the top of the head, the shape of the skull may be altered and its diameters affected. Many fractures, then, are the result of a bursting force, which may be shown by the fact that hair has been found included within apparently closed fissures, and even on the dura. Moreover, particles of bullets have been found within the skull without any visible opening through which they could have entered, showing that the bone has yielded under impact for a fraction of a second. In certain injuries to the head, as when a man is struck to the ground, there is injury at two points nearly opposite.
Fractures of the skull, especially of the vertex, possess surgical interest mainly as they are accompanied by more or less evidence of intracranial complications. So long as there is no evidence of hemorrhage or laceration within they are ordinarily regarded as a feature of the external wound with which they are usually found, and unless there be comminution, depression, or some other good reason for operating they are covered over as the wound is closed and are left to the natural process of repair by formation of minute callus or by the ossification of granulation tissue.
It is unfair to contrast the results of the surgery of today with those of the pre-antiseptic era. Rules then enforced are now abrogated. One respect in which we violate precedent is in our disregard of the periosteum or pericranium. This is sacrificed without hesitation when found to be infected or torn or lacerated beyond repair. A flap of scalp will adhere as readily to denuded bone as to periosteum, and skin grafts can be applied and will adhere to this same bone—if not upon the first day, a little later when granulations have appeared. In the various plastic operations necessitated about the head we may also transplant flaps upon otherwise uncovered bone without the slightest hesitation. Fractures should be treated mainly in accordance with intracranial complications, or through what can be seen either through the wound or through an opening intentionally made under antiseptic precautions for purposes of exploration. It is conceded to be better policy to remove fragments of bone whose vitality is uncertain and to sacrifice tissue injured or lacerated to such an extent that sloughing would probably follow or be so exposed as to have become infected.
Diagnosis of Fractures of the Vertex.
—In the absence of an open wound, and unless incision be made, diagnosis of fractures of the vertex is necessarily conjectural. In the presence of a wound diagnosis is usually easy. In case of a small puncture it will be better to enlarge it sufficiently to permit the introduction at least of the finger. With the finger and the eye we seek to detect differences in level, depressions, fissures, etc. Mistakes arise from the formation of an exudate or a clot, by which a depression of the soft parts may be regarded as depression of the bone. Error occasionally arises from the existence of previous atrophy of the bone or any congenital defects in ossification of the skull; also in the skulls of syphilitic patients where disappearance of a gumma is often followed by absorption of the underlying bone. In case of doubt exploratory incisions should be made under aseptic precautions. These should not be made, however, unless the attendant is ready—i. e., has the facilities immediately at hand—for carrying out any further operative procedure that may be necessary, as elevation of fragments, removal of foreign bodies, etc. Error also may arise from mistaking for fracture a deceptive circular effusion of blood which frequently occurs beneath the scalp after injury. Areas of bloody infiltration often have abrupt margins which are calculated to easily deceive. In children, more especially, we often have a circumscribed bloody tumor which may contain cerebrospinal fluid rather than pure blood. In some of these cases after exploration there will be found material resembling brain matter, which, however, is not always such, although real brain substance may escape, caused by rupture of the overlying membranes. Should it be noted that the fluid used for irrigating and cleansing such a wound begins to pulsate, it will imply connection with the cranial cavity, and, obviously, fracture. A suture should not be mistaken for a line of fracture. This mistake is more easy when Wormian bones are present. Blood may be wiped away from a suture line, but not from that indicating fracture. It is not often possible to diagnosticate an isolated fracture of the inner table. It happened, however, once to Stromeyer to notice that so soon as an injured patient assumed the horizontal position he began to vomit, and that nausea subsided when he was placed in the upright position. On autopsy it was found that there had occurred a depressed splintering of the inner table with perforation of the dura—less irritation was produced in the upright position than when the patient was lying down, which accounted for his vomiting when in the horizontal posture. When a comminution has been produced it is always of prognostic value if an unbroken dura be found. Prolapse of brain substance is a serious complication. Escape of cerebrospinal fluid is relatively rare. Rising temperature after these injuries is always a sign of danger.
Treatment.
—Treatment comprises attention to the local injury and the suitable dealing with the condition of the brain within when injured. The treatment of simple fractures is expectant. In the absence of indication for operation it should be simple, and should consist of physiological rest, aseptic dressings, ice applications to the head, the administration of such laxatives, diuretics, antacids, etc., as may be necessary to favor free excretion and to guard against autointoxication. Whenever there is reason to suspect a depression, exploratory incision should be made. Actual depression, whether the fracture be compound or not, requires operation. This course is justified by the numerous instances in which later consequences have been noted, such as traumatic epilepsy, insanity, etc.
Compound injuries should always be operated upon in some manner, which includes the removal of loosened splinters, the elevation of depressed bone, the removal of foreign matter, the checking of hemorrhage, the excision of bruised and lacerated tissue, and the proper closure of the wound, with or without drainage.