Fig. 226
Osteogenesis and osteosclerosis in slow infective processes. (Buffalo Museum.)
Periostitis Albuminosa.
—This is a rare manifestation of bone disease, only given an identity of its own since 1868, when Ollier first distinguished it, since which time it has been the subject of considerable controversy. The name refers to a condition less acute than the infectious periostitis just described, almost always localized in a single bone, necessitating incision and evacuation of a fluid which is gelatinous or mucoid in appearance rather than purulent. It is because of the peculiarity of the subperiosteal collection of fluid that it received the name periostitis albuminosa, and it was not generally regarded until recently as a variety of the infectious form of periostitis. It is, however, now conceded as being a mitigated form of infection, in which the products of exudation assume the serous rather than the purulent type. In some instances it appears to be the tubercle bacilli which are at fault. At all events, the organisms which produce the disease are more or less virulent, else the clinical form of the disease would be less serious than it really is. Cultures made from these subperiosteal collections have in almost all recent instances revealed the presence of some one of the numerous pyogenic organisms. Quite recently Dor has described a polymorphic microbe, in instances of this kind, which he has called the Bacillus cereus citreus, with which he claims to have been able to reproduce the disease in animals.
Chronic and Latent Osteomyelitis.
—As in the lungs, however, chronic lesions are met with, and as in the lungs, again, it is possible for collections of microörganisms to become more or less encapsulated and for a long time to lie latent until some provoking cause excites them again into activity. In this way are to be explained the numerous instances of recurring abscesses within the bone necessitating repeated operations, often at long intervals. (See [Plate XXXVI].)
Possible Consequences of Any and All of the Bone Infections.
—Bone is a living tissue, calcified and stiffened by inorganic material for the purpose of giving it strength; it may suffer remotely from the consequences of local infections, the same as other tissue. Thus it may have its nutrition impaired so as to produce atrophy on one hand, or increased so as to lead on the other to hypertrophy, either regular or irregular in outline. Again in its texture it may be altered to a wide extent between the sponginess or porosity on one side (osteoporosis), or to the density attained by ivory (osteosclerosis) on the other. Similar changes are also noted in cases of bone tuberculosis, which is to be considered by itself. The densest bone has sufficient vitality to permit its nutrition and life, and may assume dimensions much larger than that of the original, and a hardness which will defy the best steel instruments should it become necessary to operate upon it. The other extreme of osteoporosis includes a condition where the bone has barely sufficient inorganic material to permit it to retain its shape and ordinary proportions. Such bone is fragile in the extreme and scarcely serviceable as a supporting tissue. The principal portion of its bulk is constituted by marrow tissue, which makes it extremely vascular, but far from strong. When spongy it is ordinarily unserviceable for its proper function. Astonishing pictures of osteosclerosis and osteoporosis side by side are present in many instances of disease, the latter being often evidence of more or less ossification of new-formed granulation tissue. This is often a happy combination, because the bone, which has been sadly weakened by disappearance of its calcareous material by liquefaction and by absorption, is reinforced along some of its lines by a pillar of osteosclerotic tissue, by means of which it still functionates as a more or less useful support ([Fig. 226]).
The operating surgeon should familiarize himself with the density of normal bone in various locations, as in many operations upon the deeper bones he detects healthy bone rather by the sense of touch and of hearing, and the resistance which it offers to his instruments, than by sense of sight.