FRAGILITAS OSSIUM

Occurs chiefly in old people, whose bones contain an undue proportion of earthy matter, are endowed with little vascularity, and filled with an oleaginous fluid. They contain an undue quantity of phosphate of lime compared to the gelatin; and the liability to fracture is further increased by the interstitial absorption of the outer shell. They are in an atrophied state, and this is often in part attributable to disuse of the limbs. This state of the osseous system very often follows upon an attack of rheumatic fever, and is met with in patients who have laboured under cancerous affections.

The bones, when in this condition, often break from the slightest force applied; as from the action of the muscles when the patient turns himself in bed, whilst walking across the room, or when endeavouring to attain the erect posture when seated on a chair. After fracture the process of reunion is extremely slow, and it does not take place at all in patients very old and of worn-out constitution. With a view to prevent the occurrence of fracture when the bones are in this condition, for it is impossible by any treatment to prevent the change in the texture of the bones, the only rational indications seem to be to keep the patient on a generous diet, and to prohibit him from making any great muscular exertion—to avoid, in fact, all circumstances likely to produce a sudden action of any particular set of muscles.

OF MOLLITIES OSSIUM, RACHITIS, ETC.

These affections differ only in this, that in the latter the earthy matter is not deposited originally, whilst in the former it is absorbed after having been deposited; in both the result is the same. The latter is peculiar to the very young, the former to those of an advanced age.[11]

Rickets and mollities ossium seem to differ also in this. In the latter there is seldom, if ever, any reparative action. The diseased process of deposit continues in the bone, the softening increases, and the patient ultimately perishes. Whereas, in rickets, the softened and yielding state of the bones is only temporary: after a time earthy matter is deposited in due quantity, and the bones become compact, firm, and solid, capable of supporting the weight of the body, though necessarily permanently bent and deformed, if proper means have not been employed during the softened condition. The thickness of the rickety bone, as Mr. Stanley has shown, takes place on the concavity, which is the situation where the greatest strength may be added with the least expense of new matter. In the same way the reparation of fractures not accurately adjusted goes on most actively in the concavity formed by their displacement.

Softening of the bones is met with at all ages, and in different degrees. It seems sometimes to be congenital, and combined with hydrocephalus. It often follows dentition, measles, hooping-cough, or other infantile diseases inducing debility. In females it seems to be produced, or at least often accompanied, by the debilitating effects of leucorrhœa, miscarriages, and floodings. Loss of blood, in any way, predisposes to it. Mercury, given in immoderate quantities, produces a softening of the bones; and, in some most remarkable instances on record, the free use of common salt was the only cause assigned. When the disease affects children, all the bones generally suffer, those of the extremities as well as those of the trunk; the limbs become bent in an extraordinary manner, and the heads of the bones are swollen, and appear to be much more so in consequence of the wasted and flabby state of the muscles. The child walks with difficulty, and in many cases the legs are utterly incapable of supporting the weight of the body, so that he cannot remain in the erect position. The chest and pelvis become deformed, breathing is oppressed, the digestive organs are deranged, and the belly is tumid. The bones of the limbs become flattened as well as bent, and in their concavities, as remarked in the preceding cut, new bone is effused, in order that the column of support may be thereby strengthened. The new deposit is of extremely dense consistence, and is effused in greater or less quantity, according to the degree of curvature.

The bones of rickety subjects are soft, cellular, and of a brown colour, contain a dark fluid, and are very deficient in earthy matter. As a simple proof of the latter circumstance, it may be mentioned that distortions of the pelvis can be, and often are, accurately imitated by soaking the bones for some time in acid, whereby the earthy matter is extracted. In many instances this component of the bones is almost entirely removed, and soft matter deposited instead; they then consist merely of an extremely thin external osseous shell, covered by thickened periosteum, and containing a pulpy substance resembling fatty matter. During the progress of the disease, the urine deposits, often in great quantity, a white sediment, which, on analysis, is found to be the phosphate of lime. In rickets the head is generally enlarged to a greater or less degree, and the bones of the cranium are thickened and spongy; not unfrequently the intellectual faculties remain acute. In adolescents and adults the limbs seldom become affected; the bones composing the spinal column are the seat of the disease, and, along with the distortion of the spine, the position of the ribs is necessarily altered. Certain rare cases have occurred, in which all the bones of the adult were softened to a very great degree. In one remarkable instance, the patient complained of an annoying sense of tightness in the limb most affected, and, on examination, the softened bone was found greatly depressed at that point, as if a strong ligature had been drawn tightly round it. Mr. Howship, who attended the patient, was so kind as to present me some years ago with a portion of the altered femur, which consists of a fatty-looking substance, and appears to contain little or no earthy matter.[13]