Senile Fragility of Bones.
—This means weakening of the bones which is incident to advanced age in either sex, due to and comprised under the term osteoporosis. Added to this, in certain places is a positive change in shape, also characterizing the senile condition—e. g., the neck of the femur. Under these circumstances bones will break with a minimum of violence and without invoking any theory of osteomalacia, osteopsathyrosis, or the like. As bone disappears under these circumstances fat usually takes its place, so that while the volume of the bone may not be particularly diminished, its weight and density are materially altered. (See [introductory remarks] to this chapter.)
Atrophic Elongation.
—This is a term first applied by Ollier, and refers to a distinct type of alteration in long bones by which their actual volume is relatively diminished, although they increase in length. It is produced largely by lack of pressure, and is seen in many amputated stumps, in which it has much to do with the conicity of the same. It is seen in certain cases of typhoid fever or in forced confinement of the young in bed, where the bones appear to grow at a much more rapid rate than normal. It may also be due to unequal amounts, or defects, of nutritive supply, especially that furnished by the periosteum, and in certain other cases seems to be a purely reflex or trophoneurotic change which is always inexplicable. Frequently accompanying it is muscular wasting, which is to be explained rather by reflex action through the cord, produced perhaps through the mechanism of the terminal filaments of the articular nerves.
Ostitis Deformans.
—Ostitis deformans is often called Paget’s disease of the bones, and is a condition found alike in long and flat bones, the osseous tissue being condensed in texture and increased in amount, or at other times the osseous tissue becoming quite porous and the spongy tissue rarefied without alteration in the marrow. It is due to the unknown causes which may be summed up in the expression trophoneurotic, a painful and a painless form having been described, the former the more frequent. It produces deformities, disfigurements, and hypertrophies of the long bones. It is distinguished from arthritis deformans, described in the previous chapter, which is a distinct malady.
In the skull it is usually the face bones which are most involved, although the disease often commences in the cranial bones. The skull proper may be thickened even to 3 Cm. The thorax becomes globular or cubic in form, the arms are relatively too long, and there is usually dorsal kyphosis; the pelvis is thickened and distorted; the ribs are augmented in size and the femora irregularly curved; the patellæ enlarged; the tibiæ more massive and their curves exaggerated. The disease is essentially symmetrical, commonly commencing in the cranium and radius. Fractures are rare, because the bones become stronger rather than weaker.
In many instances these changes are accompanied by severe pains, which may be exaggerated by pressure. The malady is usually regarded as rheumatism, but it may be said that even were accurate diagnosis made early it would scarcely avail in treatment, since there is none for it. It may require to be distinguished from hereditary syphilis, in which the tibiæ have more of the saber shape; from acromegaly or leontiasis, which begin in the bones of the face and involve the cranium only secondarily.
Osteoarthropathie Hypertrophiante Pneumique.
—Under this title, which has no exact equivalent in English, was described, in 1890, by Marie, a peculiar affection, often wrongly spoken of in this country as Marie’s disease. This is in large part a pulmonary affection accompanied by enlargement of the extremities. There is reason to believe that there are present microörganisms, giving rise to products that are absorbed into the general circulation, the result of whose presence is an irritative hypertrophy of certain parts, particularly the joints and ends of the fingers, the elbow-, shoulder-, and knee-joints, and often the wrist. There is also ordinarily dorsolumbar kyphosis, which in acromegaly is usually cervicodorsal. The cranium remains intact; the borders of the jaw are sometimes involved.