sequence in children than in adults, partly on account of predominating reproduction, and partly on account of the less contractile power of the muscles. In more advanced age reproduction already has declined, and phosphate of lime is very largely deposited in the bony tissue; hence the fracture heals with more difficulty. All diseases which alter the nutrition of bone, (par. 575,) as well also as a great degree of weakness, more or less prevent the cure of the fracture. Although pregnancy, in so far as the living activity is then concentrated at another point, may retard or hinder the firm union of the ends of the bone, yet numerous observations show that in general this is not the case. 578. When the ends of the fracture are early brought into a corresponding position, and there retained, they unite in the same way as divided soft parts, (par. 272,) that is, the ends of the bone inflame, are glued together by a gelatinous substance, and the vessels shoot into this connecting mass; the connexion is at first yielding, till by deposition of phosphate of lime it becomes hard. For the first ten or twelve days there is swelling of the soft parts, which gradually subsides, and then a circumscribed swelling remains around the ends of the bone. Hitherto the patient feels crepitation at every motion. Between the twelfth and twentieth day, it may be ascertained that the ends of the bone are actually connected, although only slightly and flexibly. Gradually the union becomes firmer, and between the thirtieth and sixtieth day motion ceases. The earlier opinions which have been advanced regarding the structure of the mass (callus) that connects the ends of the fracture, are more or less one-sided and partially false, as sometimes they have derived it from a secreted glutinous and gradually hardened matter, sometimes from organization and ossification of the blood; sometimes from scarring and ossifying of the periosteum or of the medullary membrane, sometimes from the production of granulations. The union of the ends of the fracture must be accompanied with those of the divided soft parts, only that in the former the connecting intersubstance undergoes the same changes as the formation of bone in its natural development. The processes which take place on the ends of the fracture are (as experiments on animals prove) the following: effusion of blood occurs in the cellular tissue, to a greater or less extent, covers the muscles and the fracture, is firmly attached to the ends of the fracture and seems to proceed especially from the medullary canal and periosteum. The blood gradually becomes paler and tougher, the periosteum swells and reddens, and beneath, as well as subsequently out of the medullary canal, a jelly-like mass capable of being drawn into threads is deposited. The swollen soft parts are daily connected more firmly by the intersubstance, which presents a soft reddish and externally fibro-cartilaginous tissue through which the aponeuroses and muscles pass, and in which the periosteum attaches itself, or is formed by the surrounding muscles and cellular tissue. In this mass bony points are first produced, at the greatest distance from the fracture, and the middle of the callus is at last ossified. The new bony mass is more firm than the rest, though this does not depend on its own greater firmness, but on the mechanical relations of the shell of the bone becoming thicker and thicker by the deposition of bone; the medullary cavity is also usually filled with it, although subsequently the bony canal is partially reproduced. As, however, broken bones are united by actual bony tissue, so, after the perfect ossification, there can be no question of peculiar callus and of different structure and substance from the original bone. The structure of new bone varies in part according to the period of its growth, partly according to the perfection or imperfection of its condition, as observed in preparations. DUPUYTREN distinguished, according to the above-described symptoms, two periods in the formation of bone. In the early period, the ends of the fracture are retained as in a brace, by the softened periosteum and swollen soft parts, and by the new bone deposited from the periosteum and medullary membrane, whilst the intermediate substance attains the condition of fibro-cartilage. This state, continuing to the thirtieth or fortieth day, he calls provisional callus. In the subsequent period, the ossification of the cartilaginous intersubstance takes place, not before the fourth or sixth month; absorption first removes the swelling of the soft parts, and then, after from six to twelve months, the bony mass in the medullary canal is removed, whereby this canal is restored. This DUPUYTREN calls the definitive cailus. For the literature of Callus, see DUHAMEL, in Histoire et Mémoires de l'Académie des Sciences. 1739-43. DEHTLEFF, Dissert. seu Ossis Calli generat. et natur. per fracta animal. oss. demonstr. Götting., 1753. MARRIGUES, Dissert. sur la Conformation du Cal. Paris, 1783. VILLERMÉ; in Journal Universel des Sciences Médicales, vol. xxviii. MECKEL, J. F., Handbuch der Pathologischen Anatomie. Leipz., 1818. vol. i. pt. ii. p. 62. BRESCHET, C., Recherches historiques et expérimentales sur la Formation du Cal: in Concours pour la place de chef des travaux anatomiques à la Faculté de Paris Paris, 1819. 4to. SCARPA, De Anatome et Pathologia Ossium Commentarii. Ticini. 1827. sm. fi WEBER, M., Die Wiedervereinigung der Knochen: in Verhandl. der K. L. Ac demie der Naturwiss. vol. xx. 2. MIESCHER, above cited. [JOHN HUNTER, in speaking of the period of union and the manner in which this effect takes place in simple fracture, says: "The time in which the bone will be united will depend on circumstances. In the soft parts union will often take place in forty-eight hours; but it will require much longer time in bones. In the first place, they cannot be brought so closely in contact, therefore a large quantity of new matter must become vascular; secondly, there is the second or ossific process to be effected; thirdly, there is laceration of the soft parts; fourthly, the state of the constitution and restorative powers may be weakened; fifthly, age. The situation of the bone, too, will cause a variation: the lower requiring a longer time than the upper extremities. In the middle-aged and of a good constitution, union will take place in three weeks, so as not to admit of perceptible motion. If much longer in uniting, it will be uncertain at what time this wil take place; I have known it months, and yet unite at last. This slowness seems to be from imperfection in the two first bonds of union, the adhesive and the cartilaginous; sometimes from a want of disposition to ossification." (p. 503.) Various observations and experiments have been made on brutes, mostly rabbits and dogs, for the purpose of ascertaining the mode in which fractures are reunited; some of the most important of these I shall now recite. BRESCHET (a) and VILLERMÉ (b), whose inquiries into the re-union of fractured bones are, as MIESCHER observes, "without doubt the most ample and complete,” have distinguished five principal periods in the course of this process. First period.-From the first to the sixteenth day.-At the onset the effused blood is found in all the soft parts, after which inflammation and swelling principally of the cellular tissue appears; the neighbouring parts of the bone itself become paler, and produce with the hardened cellular tissue a regular, almost cartilaginous substance. The periosteum is rent in pieces about the fractured part, is separated from the bone, and between them both a small quantity of viscid matter is seen; the periosteum on the tenth day has swollen to the thickness of two-thirds of a line, and adheres firmly to the mus cles and to the hardened cellular tissue. The medulla is torn asunder, and the blood poured from it forms a stopple in the medullary canal; within it also blood is exuded, and the colour of the medulla is consequently more dingy. From the fourth day the medulla assumes a brighter red colour and more solid, then becomes whitish, and the substance produced by it, soft at first, becomes cartilaginous, and at last osseous, adhering with the bone itself. The surfaces of the fracture are at first concealed by coagulated blood; presently a little viscid matter is seen on them, which gradually increases in quantity, becomes firmer, is seen to proceed from the medullary canal, and covers these surfaces, which, from the tenth day, are somewhat smoothed and rounded, and at last unites with the neighbouring soft parts. This is their substance intermédiaire. (a) Recherches historiques et expérimentales sur le Cal; in Concours pour la place de chef des travaux anatomiques. Paris, 1819. (b) Dictionn. des Sciences Méd., vol. xxxvii. p. 416, Article-Ossification du Caí. Second period-Fibrous or fibro-cartilaginous state, from the sixteenth to the twentyfifth day. The cellular tissue nearest the external surface, again softens and returns to its healthy state, whilst the soft parts below are daily more firmly united with the intermediate substance, and with it distinctly bound the circumscribed swelling of callus, in which the fragments of bone are, as it were, involved. This swelling consists principally of two substances, of which the outer, whitish, cartilaginous in appearance and density, here and there entirely cartilaginous, lies over the bone to some distance from the seat of fracture, and at the most distant point from the fractured part now presents the hardness and appearance of bone: the internal substance of the swelling is reddish and thin, adheres closely to the surfaces of the fracture, but more loosely to the first denuded surface of the bone not yet altered, and thus forms an intermediate substance; both tissues gradually and indefinitely pass the one into the other. The periosteum, swollen at those parts which have now become changed into cartilage and bony matter, is easily distinguished and separated, but around the middle of the fracture appears entirely united with the swelling of the callus. The medullary tube is obliterated with compact or porous bony substance. Third period.-From the twenty-fifth day to the third month.-Ossification commences at the part most distant from the fracture in that fibrous substance which is changed into cartilage, whilst, at the same time, the red intermediate substance is converted into fibro-cartilage. Thus the whole swelling at length becomes bony; still, however, there may be some motion, and if the bone be cut lengthways with a saw, a white streak will be observed traversing the callus in the region of the fracture, with which the swollen periosteum is adherent. The medullary tube is obliterated; the soft parts have returned to their healthy state. Fourth period.-Bony state; from the third to the sixth month.-The streak is still seen for a long time on the external surface, either with the periosteum more firmly adhering, or with a little remaining groove; within, as soon as the larger medullary cells begin to be formed, it disappears. Fifth period.-Diminution of the Swelling. Restoration of the medullary tube.—The bony substance filling the medullary tube becomes cellular; the cells enlarge, and at length entirely disappear, and in their stead the healthy medulla appears. In the callus also cells are produced, and the size of the swelling being simultaneously diminished, the external crust becomes compact. From this digest of the observations of BRESCHET and VILLERME, which is given by MIESCHER, from whose work I have copied it, it appears, as he says, that these writers, "although they consider the formation of the callus does not so much originate from the periosteum alone as that it is formed between the bone and the periosteum, in this respect, however, agree with DUPUYTREN, that they confirm the double formation of bony substance; of which the one, produced in the external surface as well as in the medullary tube, afterwards disappears, (cal provisoire,) whilst the other, formed between the fractured parts themselves, remains and by degrees becomes more firm (cal définitif.)” (p. 119-121.) MIESCHER, endeavouring to settle the disputed points in regard to the production of callus, proposes to himself the following questions:-" Whether, according to the laws of nature, it can be that the inflamed periosteum can be converted into bone; which seems from WEBER'S observations to be effected; BRESCHET, VILLERMÉ, and MEDING hold that the plastic substance exuded from the internal surface of the periosteum, can alone be ossified, which, however, SCARPA entirely denies is ever converted into bone. The other question, whether really there be a formation of bony substance, such as DUPUYTREN says is formed, temporary or provisional, or not at all; if it exist, what is its nature, what its purpose? It is also very doubtful whether the bone itself remains unchanged, or, being softened, is rounded by absorption, wastes, or lastly is loosened up and swells." (p. 125.) Our space will not permit following the interesting history of MIESCHER'S inquiries upon these points, and we must therefore be content with the following summary which he has given of their results: "To one considering these observations, the theory of the formation of the callus appears extremely simple; for it is produced, as in every reunion, by the first intention, by the exudative inflammation of all the parts injured by the fracture; but the bony callus originates from that exudation which proceeds from the bones. We observe the inflammation first in the soft parts, the periosteum, the cellular tissue, and the muscles; all which becoming swollen, hardened, and consolidated together, surround the fracture with, as it were, a pretty firm capsule. The inflammatory exudation is clearly perceived in the internal surface of this capsule, from which I have frequently noticed that reddish semi-fluid substance produced which gradually becoming firm is provided with vessels, and not infrequently has the appearance of kennels or cartaces By the same infammation there springs from the netary tissue, at the place of fracture, a soft reddish supstance which covers the surfaces of the fracture, and casting with the mater exped from the soft parts, produces the intermediate substance. All these materials poured forth from the infamed soft pars in the cellalar-ftros texture, are as tea changed, and fill the intervals between the fragments via De Exles, cellular teme, and periostran gradually recum to their firmer condition. The bone itself is the attacked with infammatic, first indeed at those parts where the Bow of blood and nutr tion have not been disturbed, that is, on the external surface, where the periosten i not been torn from the bone, and on the internall where the vessels of the medulla and of the bone are still mined wgether. Hence is eroded a reach white, transparen gelatinous fuld, scarcely differing from that poured out in infamed soft parts. This by vessels gradually forming in it is thanged into an organic tissue, and whilst at the we part it increases in quantity, at the other, and first indeed where sconected with the wor it is converted into cartaginoes and bony substance. This within, is the medley tube obliterated near the fracture, with new bony matter; without, this substance p trading gradually, and propagated from both fragments towards the fracture, at les stretches beyond the bare surface of the fractured ends and at last, as it may chance, a nects both, either throughout their whole extent, or only here and there, Such a formation of PRIMARY CALLUS. Whilst these processes are going on, the surface da bone first bared unites with the capsule formed by the soft parts, and with the promise part of the primary callus itself, but the edges of the fracture with the internets substance; by which means the fow of the hamours being renewed, by it also is the formation of bony matter, that is, the formation of the SECONDARY CALLES, product From all these parts, then, which I have mentioned, new bony materials gradually a creasing in turn come nearer, and the intermediate substance which in the mean while had occupied the ligamentous structure, being got rid of, they at length unite together. Th does callus arise from the bony substance projecting on every side from the fragment near the fracture; and is gradually perfected in exactly the same way as the original bone itself. Which concluded, it becomes part of the bone itself, and at last is so const dated with it, into, as it were, one body, that oftentimes, even with the assistance of the microscope, it cannot be determined what should be assigned to the callus, what to the original bone." (pp. 141, 42.)} 579. The callus often does not attain its proper degree of hardness in the usual time, which depends on the insufficient contact of the broken surfaces, on the frequent movements of the limb, on the already often mentioned dyscrasic diseases, on much advanced age, or especially on weakness of the living activity, and on considerable tearing of the periosteum. The broken ends are connected in these cases either merely by a cellulo-fibrous mass, and are in apposition or not, or they scar and include neighbouring parts between them; the ends of the bone remain movable, and the natural motions of the joint are either completely prevented or rendered very difficult: thus an artificial, unnatural joint, is produced. Fracture of the neck of the thigh-bone, (within the capsule,) of the olecranon, of the knee-cap and heel-bone, in most cases do not unite by bone, but by a tough cellular int substance. This partially depends on the violent muscular action which displaces the ends of the fracture, and partly on these bones being covered with a thick, tough tendinous tissue, which causes the want of external ossification and swelling of the periosteum, as well as the change called by DUPUYTREN, provisional callus, which keeps the ends of the fracture in sufficiently close contact for ossification. Experiments prove that the periosteum, both in the neighbourhood of the epiphysis and where the tendinens expansion spreads over bones, is loosened with more difficulty by inflammation, and that no bony matter is deposited (a). From this circumstance, the opinion that want of the periosteum is the cause of want of union, has especial value. The great looseness of the fragments, the yielding of the muscles, the small surfaces, capable of touching, of the little substantial knee-cap and olechranon, are to be borne in mind, as well also as to the poverty of vessels in the isolated head of the thigh-bone; and it is therefore readily perceived that the ossification of the inter-substance must be subject to great dificulty. But the opinion, that bony union never can take place, is not true (1.) (a) MEDING; above cited, [(1) The usual absence of union in these fractures must be attributed solely to the difficulty of keeping the fractured surfaces in close apposition and at perfect rest, to both of which conditions the muscles offer great obstacles. But if these can be overcome, there is ample proof, as will be hereafter specially shown, that such fractures can unite. And that want of union does not depend on want of power to secrete bone, is proved by the large masses of bone often produced about the fractured parts, although no union occurs, of which examples in fractures of the neck of the thigh-bone, of the condyles of the upper arm-bone, and of the coronoid process of the cubit, are in the museum at St. Thomas's, as well as in many others.-J. F. S.] 580. If the ends of the fracture touch only partially, they unite at that part alone, and mostly this partial connexion is surrounded with a considerable growth of callus. This is also the case when the ends of the fracture are split. The growth of callus may be therefore consequent on a too loose bandaging, because the broken ends are not thereby kept in apposition. 581. The treatment of fractures consists generally, 1. In the proper disposition of the fracture, if the broken ends have been displaced. 2. In retaining the ends of the fracture in their proper corresponding position with a suitable apparatus. 3. In preventing and getting rid of the consecutive symptoms. 582. Before proceeding to the arrangement of the fracture, the parts must be carefully unclothed; and also, in the necessary transport of the injured party, great care must be taken that the ends of the fracture be not more displaced, and do not injure the soft parts. The setting (Repositio, Lat.; Einrichtung, Germ.; Reduction, Fr.) of the fracture consists in overcoming the contraction of the muscles by extension and counter-extension, and then by direct pressure, to bring the two ends of the fracture into actual contact (Conformatio, Coaptatio.) Extension and counter-extension are made by assistants, the one holding the limb below the upper, and the other above the lower joint of the broken bone, and drawing in opposite directions; but first always in that of the lower piece of bone, and afterwards in that of the limb. When sufficient extension has been made, that is, when the ends of the fracture are somewhat separated from each other, the Surgeon, grasping them with both hands, must endeavour to bring them into corresponding position and contact, and to smooth all irregularities. 583. The retention of the limb in this position depends on the apparatus, during the application of which the proper degree of extension and counter-extension must be kept up. The apparatus must completely enclose the whole limb, by its regular pressure must render the displacement of the ends of the bone impossible, and prevent the motions of the limb. For this are requisite-1st. The swathing of the whole limb with several strips of bandage, (or with the eighteen or twenty-tailed bandage,) or in the upper extremity with a common circular bandage, after a compress has been put upon the seat of fracture (1). These parts of the apparatus must previous to their application be moistened with a resolvent lotion, as for example, lead wash, if continued moisture seem fitting for the prevention or diminution of severe inflammation, otherwise they should be applied dry, and are to be put on neither too tight nor too loose. 2dly. The application of splints. These are either flexible and take on the form of the limb, as splints of pasteboard, of leather, of flexible wood, of wooden or fishbone rods sewed up in linen; or they are inflexible, of firm wood, or of lead, more or less corresponding to the form of the limb (2). The firm unyielding |