Elements of Surgery. Robert Liston

      Suppuration in bones is necessarily connected with loss of substance, and condensation of the surrounding parts; and purulent collections exteriorly, if allowed to press long, or if bound down by unyielding sheaths, will sooner or later produce a breach of continuity, by causing absorption of the outer lamella and the subjacent cancellated texture. A similar effect is produced by aneurismal and some other tumours. Such loss of substance is, in some instances, speedily repaired, after removal of the cause, by effusion of new matter from the surrounding bloodvessels of the bone; thus, in disease in consequence of pressure from large aneurism, there is reason to suppose that the healing process commences as soon as the aneurismal sac begins to diminish, as after operation. But, as has been already observed, the healthy actions are more vigorous in the softer tissues than in bone; and when ulceration has occurred in the latter, it is generally attended with weak action, and presents the same general characters as an ulcer in the soft parts, connected with a feeble action of the bloodvessels; the discharge is thin and fetid, absorption gradually proceeds, and there is little or no effort towards reparation. Cavities in bones are necessarily slower in healing than those in the soft parts; the vitality and power of reparation are lower; and there being no elasticity in the parts, the walls cannot come rapidly together, contract and coalesce. It may tend to prevent confusion of the two different morbid states, if we confine the term ulceration to suppuration in, and absorption of, bone, whilst the vessels retain a considerable power of action, throw out new matter, and procure a reparation of the breach; and this condition of the osseous tissue exists when the disease is situated in the surface of the bone, and when it has been produced by an external cause. On the contrary, the term caries will denote that peculiar kind of ulceration in which reparation is hardly attempted by nature, and is with difficulty obtained by the most active interference; and this disease will most generally be found to affect the cancellated structure. The comparative frequency of one or other of the terminations of inflammation depends much on the kind of bone implicated.

      CARIES

      Caries most frequently occurs in the heads of long and in the cancellated structure of the short bones, as unhealthy suppuration most frequently takes place in the loose, fatty, and cellular tissues of the soft parts. The formation of abscess in the cancelli is generally preceded by deposit of tubercular matter, isolated or collected in masses, and by the softening of this cheesy substance. When pus has formed in the substance of a bone, the outer lamella, in the end, becomes absorbed, and the effusion undermines the periosteum, which, from the distension, also ulcerates: the matter then spreads into the neighbouring cellular tissue, or makes its way to the surface, and is evacuated, or, what is still worse, it escapes into an articulation. The discharge is often continued, as already stated, in consequence of a dead portion of the cancellated structure being imbedded either in the carious cavity, or in the soft parts, where they sometimes are lodged for a long period.

      It was formerly remarked that bones become highly sensible from incited action; hence, during the progress of this disease, which is attended with more or less inflammation, the patient generally suffers most excruciating agony—so great, in general, as to prevent him, perhaps for weeks, from enjoying the least repose. The affected part is considerably swollen, but the enlargement is seldom so general, or so great as in the diseased state of the ligaments and other apparatus of a joint. White swelling, however, may be the precursor of caries; or, in other words, a disease commencing in the bursæ, ligaments, synovial membrane, or cartilage, may extend to the bone; and breach of continuity, attended with weak action, be the consequence. In caries the affected portion appears neither to possess vitality enough to enable it to repair the breach, nor to be sufficiently deprived of vitality to be thrown off by the surrounding parts. Considerable portions of dead bone are occasionally found in carious cavities, in the heads of bones, and even in the vertebral column. Small portions are also detached piecemeal in the progress of ulceration, and discharged; but it is seldom that the whole surface is thrown off, so as to give place to a healthy and reparative action. When the parietes of the cavity have remained a considerable time in this inactive state, the surrounding vessels become more active, and the surface of the bone in the vicinity is studded with nodules of new osseous matter. The disease here delineated affected only a small portion of the cancellated texture of the condyle. An ashy looking substance fills the cavity, and this again was concealed in the recent state by lardaceous matter. The elbow joint is unaffected, excepting only that, from the deposit of new bone in spiculæ and nodules, and the condensation of the soft parts, almost complete anchylosis had taken place. This deposit is not always limited to the affected bone, if one only be the seat of the disease, but frequently extends to those articulated with it. The soft parts are commonly more or less thickened, and rendered exceedingly dense by effusion of lymph into the cellular texture; and so great is this thickening sometimes, that the knife is resisted as if by cartilage. The discharge which proceeds from the carious part is generally highly fetid, very profuse, is often poured through several openings, and the surrounding skin is excoriated and generally of a livid colour. The ichorous discharge occasionally dries up for a short period and again breaks out more violently. The surface of the ulcer is, in some cases, occupied by soft unhealthy granulations; in others the earthy part of the bone is most prominent. When the parts have been macerated and dried, the disease is often found to have proceeded more in width than in depth, and the absorption has not reduced all points of the diseased surface to the same level, thin portions remaining somewhat elevated, and giving the part a cancellated appearance; and there often project numerous minute osseous fibrillæ of considerable length, which intermix with one another, and form a most delicate network. In other instances, the ulceration has extended more deeply and uniformly, and a considerable cavity is formed, with irregular margins and surface; not unfrequently it contains dead portions of the cancellated structure, in some of a dark, in others of a light colour; or it is occupied, in the recent state, by a substance resembling lard. The surrounding bone is much softened, and, after maceration, becomes exceedingly light. The disease is generally confined to one or two bones, but occasionally involves a whole chain. It may be limited to a part of one bone in a joint, or may embrace the whole of it. Its extent will depend on the severity of the primary action, or on the degree and duration of the pressure of fluid which has been allowed to exist, whether from the nature of the superincumbent texture or the carelessness of the surgeon.

      Interstitial absorption of those bones which are in the neighbourhood of the carious ulceration often occurs in the tarsus and carpus. The superincumbent integuments are livid and cold, and pain is felt in the situation of the bones; yet they are not affected with continuous ulceration, but portions of their substance are gradually removed by absorption, so that they are much loosened in texture, and may be altogether destroyed, or come to consist merely of a thin and reticulated osseous shell, whilst at the same time their cartilaginous surfaces often remain in their healthy condition.

      The constitutional disorder attendant on caries is at first very great; the sympathetic fever is followed by hectic, under which, and the discharge, many patients sink. The general affection in some degree keeps pace with the local in violence and duration. The irritation is in some cases so great as to destroy the patient in a very few months or weeks; but not unfrequently a constitution, by no means strong, will be enabled to bear up for a long period under very extensive disease of a bone. The paroxysms of pain and inflammation occasion fresh attacks of constitutional derangement: this occurs till the patient’s health and strength are exhausted, and he sinks under the disease, or is relieved by the spontaneous or artificial removal of the cause.

      A natural cure of caries may occur in consequence of the diseased parts so far recovering their natural degree of vascular action as to form granulations and repair the breach; but most frequently it is necessary, for the accomplishment of this purpose, that incited action occur to a very considerable degree; and the diseased parts, already extremely weak, have not sufficient power to withstand the action, but perish; whilst the action of the surrounding parts, not being increased to such a degree as to overcome their powers, throws off the dead, secretes a more bland discharge, and deposits healthy granulations, which gradually fill up the cavity.

      Treatment.—In