Page:The American Cyclopædia (1879) Volume VII.djvu/372

 364: FRACTURE two quantities being identical. The dividend number is called the numerator, because in arithmetic it numbers how many parts are taken ; and the divisor is called the denomi- nator, because it names the parts. These terms are retained in algebra, where it is evident that their literal meaning is inapplicable. Frac- tions are also used to express the ratio of the numerator to the denominator. Thus the ex- pression ( j^~ b may signify the ratio of the sum of the quantities a and 5 to their difference, or the quotient arising from the division of that sum by that difference. The propriety of in- dicating the quotient and the ratio by the same sign is evident from the consideration that the quotient bears the same ratio to unity that the dividend bears to the divisor. A decimal frac- tion is one whose denominator consists of 1 with zeros annexed, in which case the denomi- nator is not written, but is understood from a point being prefixed, with zeros if necessary ; thus, -371 means ^V I ' O3 ' rl > if ,Ur and so on. A continued fraction is a fraction whose numerator is 1, and whose denominator is a whole number plus a fraction whose numera- tor is 1 and denominator a whole number plus a fraction, &c. FRACTURE, in surgery, a disruption or sepa- ration between the parts of a bone or cartilage, produced by external violence or the sudden and forcible contraction of muscles. The frac- ture is said to be simple when there is no ex- ternal wound; compound when complicated with lesion of the surrounding soft parts ; and comminuted when the bone is broken into many fragments. Fractures may occur at any time from the end of intra-uterine life to ex- treme old age; in youth, fractures are com- paratively rare on account of the elasticity of the bones, and in advanced life common from their brittleness. Ruptures of vessels and nerves are the most dangerous complications of fractures of the extremities; gangrene is often the consequence of the former, and paralysis, convulsions, or intense pain and in- flammation, of the latter ; comminuted frac- ture is very apt to be followed by tedious suppuration, necrosis, false joint, or much shortened limb ; dislocation also is not unfre- quently added to fracture. Fractures may be transverse or oblique; the former are most common in children, and are accompanied by little displacement ; the latter are the most frequent, and often require all the surgeon's skill and sufferer's patience to effect permament reduction and prevent deformity of the limb. The causes of displacement in the ends are muscular contractions and the weight of the fractured part ; the lower fragment rides over the upper, sometimes to the extent of several inches. The bones most liable to fracture are the superficial ones, like the clavicle, tibia, and skull ; or such as, like the radius in the fore- arm, are likely to receive the weight of the bo<iy daring a fall ; old age, caries, and cancer- ous, scorbutic, and venereal diseases, predis- pose to fracture. Violence applied to a part does not always produce a direct fracture ; for instance, a fall upon the shoulder may indi- rectly break the clavicle ; the kneepan and the olecranon are the bones most commonly broken by muscular action. The physiologi- cal symptoms of fracture are pain and inability to move the limb ; the physical characters are unnatural mobility of the parts, change in the length, direction, or form of the limb, and crepitation when the broken fragments are moved upon each other. When there is great swelling, it is often difficult to ascertain the nature or even the existence of a fracture. The course of a simple fracture is a painful and inflamed swelling a few days after the acci- dent, with more or less febrile reaction ; these gradually subside,' and with proper treatment the bone unites in from one to two months, with or without deformity according to cir- cumstances not always under the control of the surgeon; when the constitution is dis- eased, or the reparative process injudiciously interfered with, union may not take place and a false joint be formed. Complicated fractures often terminate in the death of portions of bone and of the soft parts, in unhealthy abscesses and tetanus, leading perhaps to fatal conse- quences unless the limb be removed. The prognosis of fracture of course depends on its situation, extent, complication with wounds, and a variety of circumstances which "will occur to every physician. The process of reparation has been described in the article BONE (vol. iii., p. 61), and it will only be ne- cessary to say here that lymph is effused be- tween the broken surfaces, which is gradually converted into cartilage, and in a few weeks into a spongy ossific mass called the provisional callus ; this holds the ends together for a few months until the permanent callus is deposit- ed between them ; the former is gradually ab- sorbed, and the latter has all the characters of true bone. In the interior of the skull, however, and in the cavities of the synovial membranes of the joints, no provisional callus is formed ; if the parts be kept in close appo- sition, bony union will slowly take place ; if not, the union will be ligamentary. The indi- cations of treatment are to reduce or set the fragments, and keep them at rest and in close contact, so as to prevent deformity ; all dis- turbing muscles must be relaxed, the ends of the bones extended, and the parts properly supported and kept in place ; the limb is ban- daged, and some kind of splint or apparatus is applied to keep it immovable and of its natural length. Splints are made of wood, pasteboard, tin, and more recently and best of gutta per- ch a, all properly padded and secured against displacement; the starched bandage, consist- ing of layers of cloth imbued with starch or dextrine, is light, firm, and capable of very exact application ; a plaster of Paris apparatus has been much used in Germany, especially