2 Now when any bone has been injured, it either becomes diseased or splits or is broken or perforated or crushed or displaced.
A diseased bone generally first becomes fatty, next either blackened or rotten; and this occurs in cases of severe ulceration or fistula, when these have become chronic or even gangrenous. And it is necessary in the first place to expose the diseased bone by cutting out the ulcer, and if the bone disease extends beyond the margins of the ulcer to cut away the flesh until sound bone is exposed all round. Then if the diseased bone appears merely fatty, it is enough to apply a cautery once or twice until a scale of Boeotian comes away; or to scrape it away until there is bleeding, which is a sign of sound bone; for diseased bone is necessarily dry. The same is also to be done for diseased cartilage; it too must be scraped away with a scalpel until what remains is sound. Then, whether bone or cartilage has been scraped, finely powdered soda must be dusted on; and nothing different is to be done when the surface of the bone is black or carious, except that the treatment by cautery or scraping must be continued for a longer time. In these cases if the surgeon scrapes he should press boldly upon the instrument that he may effect more and finish sooner. The end is when white or hard bone is reached. White bone instead of black, or hard[p. 495] bone instead of carious clearly indicates the end of the diseased part. I have already stated that sound bone also bleeds to some extent.
But if in either case it is doubtful how deep the disease has reached, in the case of carious bone, this is readily ascertained. A fine probe is introduced into the hole, and according as it enters to a less or greater extent, it shows either that the caries is superficial or that it has penetrated more deeply, With black bone it is possible to form some opinion also from the pain and fever; when these are moderate in degree, the disease cannot have penetrated deeply. This becomes more obvious, however, when a trepan is used; for the limit of disease is reached when the bone dust ceases to be black.
Therefore, if caries has penetrated deeply, by means of the trepan holes are bored in the bone at frequent intervals, equal in depth to the extent of the disease; next cautery points are passed into these holes, until the bone becomes entirely dry. For after such applications, simultaneously the diseased part separates off from the bone underneath, and the cavity will make flesh, and no humour or very little will be subsequently discharged.
If on the other hand the disease, whether blackness or caries, has extended to the other side of the bone as well, excision is required; and the same can be done when caries has penetrated right through a bone. But whatever is wholly diseased is to be wholly removed; if the lower part is sound, only that which is corrupt should be excised. Further, if there is caries of the skull or breast-bone or rib, the cautery is useless, and excision is necessary. Nor are we to listen to those who await the third[p. 497] day after the bone has been laid bare before excising; for all cases are treated more safely before the inflammatory reaction. Therefore, whenever possible at the same sitting, the skin is to be incised, and the bone exposed, and freed from a that is diseased. And much the most dangerous case is in the breast-bone, for even if the operation has been successful, complete healing scarcely ever results.
