4. For removal of tumors.
5. To compensate for defective development.
6. For exploratory or purely empirical reasons, including the making of “relief openings” for relief of pain, etc.
Aside from the ordinary methods of trephining as applied for common conditions, modern surgery comprises the resort to essentially new methods for raising areas of skull of considerable size and then restoring them to their previous position. These are ordinarily spoken of as osteoplastic resections, and have added very materially to the art and resources of the surgeon. These consist, in a general way, of the formation of a window, as it were, in the vertex or lateral region of the skull by outlining a quadrangular or horseshoe flap of scalp, which is detached only for a slight distance around the incision, after which, by use of the revolving saw or by chisel and mallet, a groove is cut through the bone running parallel with the margin of the scalp-flap, but perhaps a centimeter within it. After this bone area is completely cut through on three sides it is then sprung up or elevated in such a way as to be broken across the base of the bone-flap. It is not at all detached nor separated from the scalp, and so when subsequently lowered into position retains its vitality by virtue of its vascular connections.
When some particular measure seems indicated in order to atone for a large defect in bone it has become quite customary to insert some artificial substitute, mainly either celluloid or a thin aluminum plate, previously absolutely sterilized and cut at the time into such shape as may be called for, but a trifle larger than the real defect, being let in or sprung in, as it were, either completely beneath the bone or into the bony opening, so as not to be easily detached or slip out of the way. By this heteroplastic method most admirable results have been achieved. I have used celluloid for this purpose in the spinal column also, closing with it the defect which remained after the extirpation of the sac of a spina bifida. It is rarely necessary to resort to this practice in the skull, as dense fibrous tissue in due time firmly protects the endocranial contents from external harm ([Figs. 386], [387], [388] and [389]).
CHAPTER XXXVII.
THE ORBIT AND ITS ADNEXA; THE EXTERNAL AUDITORY APPARATUS; THE ACCESSORY SINUSES; THE CRANIAL AND CERVICAL NERVES; THE ORBITAL CONTENTS AND ADNEXA.
INJURIES OF THE ORBIT.
Intra-orbital hemorrhage is not uncommon after injuries to the head. It may result from rupture of orbital vessels proper or by escape of blood from within the cranium, either outside or beneath the dural prolongation which constitutes the sheath of the optic nerve. When extensive it may produce a pulsating tumor, and this may, in time, become practically a traumatic aneurysm. After basal fractures blood frequently will escape forward so as to appear beneath the conjunctiva. Collections of blood in the orbit may also interfere with the return circulation in such a way as to lead to extensive chemosis of the conjunctiva or edema of the lids and orbital contents. Pressure may cause temporary disturbance of vision. Should there be absolute blindness it may be inferred that there has been injury to some part of the optic tract. Protrusion of the globe is an indication of the degree and amount of extra-ocular hemorrhage, which may be very pronounced. When visual symptoms are bilateral, while external evidences are confined to one orbital region, it may be assumed that there has been intracranial disturbance as well, with laceration along the optic tract. Such immediate damage will in time be followed by the ordinary symptoms of neuroretinitis and atrophy.
The more external the injury the more quickly will it yield to ice-cold applications. There are times when incisions for relief of tension may be desirable. An extensive clot in the orbit which seriously displaces the eyeball, and which does not quickly absorb, should be evacuated by an incision, either directly through the lid or beneath the lid and outside of the globe.
Penetrating injuries, like gunshot wounds, are usually easy of recognition. If vision be instantly and completely lost the harm done to the optic nerve or the globe will probably prove irreparable. Foreign bodies penetrate from various directions, and sometimes to such a depth that they are difficult to find. I have seen a large chip of wood completely lost within the orbit, and such bodies may enter either from outside or from within the nasal cavities. A foreign body will nearly always limit the motility of the globe and usually displace it. If its presence can be ascertained or revealed before operation it should be sought and removed at the expense of almost any and every other indication. If its presence be suspected it may be sought for, even though a skiagram fail to reveal it. When the usefulness of the eye is destroyed it will be advisable in such case to remove it in the progress of this search.