FRACTURE of a bone may be the result of accident, muscular action, or disease. 'The long bones of the,limbs are more subject to the latter two causes than those of the head or spine. Predisposing causes to fracture are frosty weather,.old age,, cancerous disease, a morbidly brittle condition called fragilitas ossium.
Some bones, as the kneepan and heel-bone, are liable to give way from sudden con traction of the muscles which are inserted into them. The subject of the injury then falls, and attributes the accident to the fall, whereas it is the reverse. A medical man, some years ago, awoke with a fit of cramp, and almost immediately his left thigh-bone 'broke with a snap. It reunited in the usual time. The sufferer from cancer of long standing, sometimes feels a bone give way under no special strain. In such cases, there is seldom any attempt at repair. The bones of old people are brittle from the •xcess of earthy materials (see BONE), and so readily give way. The bones of the feeble patient, with fragilitas or mollities ossium, are soft and friable, and when examined, are _found saturated with a greasy substance.
There are some persons who seem liable to fracture without any such reason. Prof. 'Gibson of America mentions a boy who, though apparently healthy, had broken his collar-bones eight times, his arm and forearm, while his leg and thigh were broken if he but tripped his foot on the carpet. An old lady once broke both thigh-bones kneel ing down in church. There is one predisposing cause to fracture fortunately now but seldom seem—viz., scurvy. Not only did it make the bones brittle, but, as was seen in lord Anson's expedition; which was manned chiefly by pensioners, old fractures again became disunited. .
Repair of a Broken Bone.—Of course, as the bone lies in the midst of soft parts, any injury to the one must tear 'the other and cause an infusion of but the latter is speedily absorbed, and is of no service in the process of repair. After the first excite ment has passed off, a fluid is effused around the, fragment, which in a short time becomes conVerted into bone. The amount of this new material depends upon the position of the fragments; should they be far apart, or, as it is technically termed, rid ing, then a much larger quantity of new bone is thrown out. We see this in animals
to such an extent that the materials for repair, or "callus," may be divided into two separate parts—a provisional callus to act as a wrapper to the bones until the permanent 'callus, or that unites the ends, however farapart, becomes sufficiently hard; then the proyisional callus, being no longer necessary, is removed by absorption.
Symptoms of Fracture. A broken liMb hangs loose, and is, as a general rule, no longer under the control of the muscles, which, however, are pricked by the broken ends of bone, and stimulated into painful spasms, which still further displace and deform the limb. Should there be any doubt, the limb may be carefully raised, and turned gently from side to tide, when a peculiar rough feeling termed crepitus removes all doubt. Each bone, however, when broken, exhibits symptoms peculiar to itself, and requires a separate treatment.
Fractures are divbled into simple, when there is no wound in the skin which com municates with the fracture; compound, when there is such a wound; comminuted being prefixed to either of these terms when the bone is broken into several pieces; impacted, when oue fragment is driven into the other; and complicated, when a neighboring joint or large blood-vessels participate in the accident.
Treatment of the fragments as near as possible to their former positions by gentle extension, retain them in place by substituting an external rigid. skeleton, made of any unyielding material which will be firm enough to resist thc spasms already alluded to, but is not fastened with very great tightness to the limb. Splints are generally of wood or pasteboard; but of late years gutta percha has been. much used. In simple fractures, it is often sufficient to adapt a bandage to the limb, which will harden on drying, and form a shell for it; for this purpose, starch, dextrine, and plaster of Paris are generally used. Whatever the splint be made of, it must keep. the bones in a state of complete rest, otherwise the lymph, which would be formed into bone, stops, as it were, half way, and becomes fibrous tissue, which allows the frag ments to move on each other, and is termed a false joint.