Elements of Surgery

by Robert Liston

OF INFLAMMATION OF BONE, AND DISEASES THENCE ARISING.

Bones grow and are nourished by the same means, and are subject to the same laws, with other parts of the system. Like all the tissues of a white colour, particularly when their growth is completed, they are less freely supplied with bloodvessels and nerves than other parts. When incited action of the bloodvessels occurs in the harder textures, sensibility is roused to an exquisite degree, and the healthy and perverted processes often advance with great vigour and amazing rapidity.

Inflammation of bone often arises from external injury, and in some constitutions from very slight causes. Its occurrence is supposed to be favoured by a syphilitic taint, but the inflammatory disposition is much more frequently produced in a system vitiated by the abuse of mercury. From the unyielding nature of the tissue, the pain attendant on inflammatory action is dreadfully excruciating; it is also most violent during the night, even in chronic cases, a circumstance which does not admit of satisfactory explanation. The integuments over the inflamed bone are swollen, and the tumour is œdematous; whilst a hard and solid tumefaction exists in the more deeply-seated parts, caused partly by enlargement of the osseous tissue and partly by effusion of lymph into the cellular substance. The bone is imbedded in a gelatinous or lymphatic effusion, situated mostly beneath the periosteum. This membrane is more vascular than in its natural condition, thickened,

and at the same time opened out in texture. The bloodvessels of the affected bone are much increased, both in activity and in size; and, in consequence of enlargement of the vessels, and thickening of the naturally delicate membrane on which the vessels ramify, the bone is swollen and increased in size; its texture, as shown in the annexed cut, is loose, somewhat resembling the cancellated structure, and its surface is occupied by numerous foramina, which are enlarged in proportion to the size of the vessels which they contain. The limb is often enormously swollen and indurated. The gelatinous effusion beneath the periosteum speedily becomes organised, nodules of osseous matter project into it, and adhere to the surface of the bone frequently by a narrow neck; these increase in number, gradually assume a solid appearance: the bone is thus thickened, often to a very great extent.

It has been supposed that the new osseous matter is deposited by the vessels of the soft parts and of the periosteum; but there can be little doubt but that it is secreted principally by the vessels which ramify within the substance of the bone, and by the vessels of the periosteum after they have entered the osseous tissue. Thus, in the case of fracture, the new osseous particles lie between the periosteum and bone at a distance from the broken ends, where the vessels are enlarged and increased in activity, or adhere to fragments which have been detached in part and retain their vitality, but not to the under surface of the periosteum. There is no doubt that thin laminæ of bone are now and then found attached to the periosteum, or impacted within its substance; but this is to be attributed to that morbid action of the tissue, to which this as well as several other membranes is subject.

When bone is extensively affected with inflammation, motion is impaired; the muscles being displaced and retarded in their action by the swelling and irregularity of the bone, by effusion of lymph into their tissue and intermuscular spaces, and, perhaps, also, by their partaking, in some measure, of the inflammatory action. Any attempt to move the parts very much aggravates the patient’s suffering. Occasionally inflammation attacks almost all the bones in the body, and causes great constitutional disturbance, by exhausting the powers of life: it sometimes terminates fatally. Bones become inflamed from various causes. However it originates, the action ends, as in the other tissues, in resolution, suppuration, or mortification. The effusion by which the diseased vessels naturally relieve themselves in softer textures cannot here take place so readily, or to such an extent as to prove beneficial: the intensity of the action is with difficulty subdued, and, consequently, resolution is comparatively rare. When it does occur, the parts do not soon regain their natural condition, but often remain considerably swollen and indurated, as is seen in nodes, which continue during the life of the patient, without causing pain or much inconvenience.

Suppuration on the surface, or in the centre, and partial or total death of a portion of bone are the most frequent consequences of external injury and incited vascular action; but suppuration in the cancellated texture frequently follows very slight incited action in those of a scrofulous habit. Tubercular matter exists, in all probability, previously, and it leads very often to long continued disease, curable only by operation. The matter may find its way to the surface after long suffering and great constitutional disturbance. Again, it may be confined for months, or even years, the patient suffering from time to time the most excruciating agony. The bone becomes thickened towards the surface by new deposit, as the cavity is increased by ulcerative absorption, and relief is only afforded, a correct diagnosis having been formed, by artificial evacuation of the matter. In many cases small sequestra lie in the cavity; and though the matter escapes naturally, or is evacuated, the patient’s strength becomes worn out, and he perishes, unless the limb is removed. So long as dead portions of bone remain, the discharge cannot cease permanently. Fresh collections are apt to form in the soft parts if the original openings close. It is no easy matter to discover or remove sequestra from deeply seated bones. A section of the femur is represented on the next page, showing a cloaca leading to the cavity of an abscess in the medullary canal. The bone is very dense in consistence, and irregular on its surface.

SUPPURATION IN BONE

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 inflammation of bone, resolution must be brought about, if possible; the other terminations are to be prevented by all possible means, since they frequently endanger the limb, and even the life, of the patient, and, at best, never admit of a speedy cure. To promote resolution, blood must be drawn copiously from the part; and general bleeding may also be required, though in some constitutions it cannot be safely carried to any great extent. After local bleeding, fomentations assiduously applied will tend much to relieve the sufferings of the patient. Purgatives, nauseating doses of antimony, and all safe measures likely to subdue the vascular action, must at the same time be adopted. Free incisions through the periosteum sometimes relieve the pain, and cut short the disease, the distended vessels being thereby emptied; but such practice is only a last resource, when the action has resisted all other means, and threatens an unfavourable termination. If, notwithstanding the resolutive means employed, the inflammation proceeds unabated, and suppuration occurs, the effused pus ought never to be allowed to remain on the surface of the bone, but must be evacuated by early incision. Otherwise the pressure of the extraneous fluid will cause absorption of the bone, or detachment of periosteum and superficial necrosis; the absorbed surface will, in its turn, secrete pus, and thus an ulcer will be produced; and, from the vascular action becoming debilitated in consequence of the previous incitation, that ulcer will in all probability degenerate into caries. Much mischief is produced by squeezing and bandaging tightly the inflamed parts, as can readily be understood; yet such practice is frequently adopted after suppuration. By it the inflammatory action is excited anew, the formation of matter is very much increased, and however useful such manipulation may be in stiffness of a joint, or mere swelling of bursæ, and sheaths of tendons, still, in inflammation and abscess of bones or joints it is extremely prejudicial, and from its indiscriminate employment by those ignorant of the profession, many limbs have been destroyed. General chronic periostitis, which is produced by exposure to cold, or occurs after or during mercurial courses, and is often supposed to be a symptom of syphilis, is relieved by the internal exhibition of the bichloride of mercury, or other mercurial preparations, combined with sarsaparilla and diaphoretics. In many instances such an affection will yield to no other treatment; and thus the practitioner is occasionally obliged to have recourse to a somewhat paradoxical practice, that of giving mercury for a disease which seems to have been produced by that mineral.

In inflammation of the short bones or heads of the long bones, if the action does not yield to topical bleeding and becomes chronic, counter-irritants must be employed. Blisters repeated are often useful in subduing the remaining action, and in obstinate cases small caustic issues are sometimes of service. During the adhesion of the eschar, the best application is a common poultice or water dressing, which, on the separation of the dead part, may be exchanged for any simple ointment, it not being at all desirable in general to check the discharge and heal up the breach of surface. Moxa is sometimes employed to make an issue in these and other cases, but it is not superior in any respect to the potential cautery, whilst its employment is generally very alarming to the patient. The sores following the use of the moxa are in some instances tedious in healing; and this may be ascribed to the vitality of the surrounding parts having been diminished by the application.

In cases of atrophy of bone, and where there is reason to suspect the scrofulous or tubercular deposit to be going on, the affected part should not be much used, and means taken to give tone to the system. Preparations of iron are often exhibited with advantage. The combination of iodine with iron may sometimes answer. Abscesses should be opened early, so as to prevent extension of the mischief. In abscess in the shafts of the long bones, it is occasionally necessary to make an opening through the outer lamella by the trephine, so as to evacuate its contents. Some instructive cases have been given by Sir B. Brodie, illustrative of the good effects of this practice. I subjoin one out of many from my own hospital practice.

“W. A., aged 22, was admitted Oct. 26, 1837, under the care of Mr. Liston. He is a policeman of weak conformation. He states that when about six or seven years of age he was first attacked with an aching pain in the right leg, near its middle, and since that period has been subject to three or four attacks every year. These usually were experienced in the spring, during rough, windy, and cold weather, and continued from one to three weeks. The pain was always aggravated at night, and so trifling in the day that he was always able to go about. These attacks ceased to occur when he was between 15 and 16 years of age, and since that time, until last May, he has been free from them. He states that up to about his 16th year the bone of the leg gradually enlarged in its middle portion, but then became stationary, and at the period of entering the police the difference between the bones of both legs was not great; this was about two years ago. Since then he has been accustomed to walk for a considerable length of time daily. During some months he was obliged to do the night work, and then he was much exposed to cold and wet. Last May, while thus engaged, he experienced again an aching pain in the middle of the right tibia; this was aggravated at night; and after a fortnight’s duration, during which it became gradually worse, he was obliged to give up his duties in the police, being unable to continue them any longer. At this time he consulted the surgeon of the subdivision with which he was connected; his treatment was fomentations to the leg and aperient medicine occasionally. Not being much relieved by this, he afterwards ordered the application of leeches on three several occasions, and mercury to salivation. At the end of three weeks he returned to his duty. In the latter part of September he was again attacked with pain during night duty; this pain increased rapidly in severity, and after three nights he was again obliged to leave duty. He was now treated again with the frequent and copious application of leeches at different intervals, and likewise took some pills, which did not affect his mouth. This treatment, with frequent fomentations, was persevered in for a month, but without permanent benefit, and then he was brought to this hospital. Has never had any syphilitic complaint.

“Present state.—Has an enlargement of the tibia about its middle third, of a diffused character, and which seems to extend a good deal inwards and backwards; in this part he experiences a throbbing and lancinating pain at night; during the day he is in general easy; at night there is considerable heat and swelling in the leg; tongue whitish; appetite good. The following pills were ordered:—℞. Bichloride of mercury, two grains; powder of gum guiacum, two scruples; oil of sassafras, ten minims; extract of sarsaparilla, four scruples. To be divided into twenty-four pills, of which let two be taken three times a day. Apply eighteen leeches to the affected part.

“Nov. 4. The leeches were repeated; much the same.

“8. Symptoms as before. As he complains of pain over the eyebrow, with nausea, let the mercury be left off. A variety of constitutional and local treatment has been pursued during Mr. Liston’s absence from the hospital, but without affording any relief; the patient’s nights were passed in great agony, and his general health began to suffer. On the 27th, after consultation with Mr. Fisher, the surgeon to the Police Force, Mr. Liston had the patient carried into the operating theatre. He made an incision along the spine of the tibia of about three inches in extent; another shorter one was made to fall on this at right angles from the inner side. The surface of the bone thus exposed was perforated to the depth of fully half an inch by a small trephine. A very dense circle was removed from the perforation; still the fluid, which was suspected to exist, did not appear. Mr. Liston, encouraged by the intense pain complained of as the process of perforation proceeded, again applied the crown of the instrument, and after a few more turns, brought out a further circle of considerable thickness, and this was forthwith followed by a flow of well-digested purulent matter.

“28. Complains of no pain comparatively; slept well last night after an anodyne draught; has felt much relieved since the operation; a good deal of matter was discharged from the sore during the night; water-dressing to be applied to the wound.

“30. Slept well without any anodyne the last two nights. The relief afforded by the operation is felt more now than it was at first. The wound discharges a good deal. A tonic mixture, containing infusion of gentian, sulphate of magnesia, and sulphuric acid, was ordered.

“Dec. 2. The wound looks florid and clean; granulations are springing up; general health very much improved.

“4. The edges of the wound are thickened by the granulations; the discharge from the wound still considerable; feels quite well in health.

“12. The wound continues much the same; the rollers have been discontinued.

“14. Feels himself gaining strength daily; can walk without pain; wound is contracting and hard; granulations seem to lessen the depth of the opening in the bone; there appears to be no sequestrum.”

When caries is fairly established, and the integuments have given way, the best and most successful proceeding is that pointed out by nature—destruction of the diseased portion; and the means must vary according to the particular circumstances. In many cases, nature seems to wait but for the separation of the sickly parts, either by accident, or by the interference of art. The means are to remove, partially or wholly, the diseased part, or to effect such a change of action as will throw it off. The first indication will be accomplished by trephines, scoops, saws, and forceps; the second by active escharotics; frequently both are required.

If there be extensive disease in the medullary canal of a bone, several perforations may require to be made, and these may be connected by the use of a small saw, or the cutting forceps. The diseased cancelli, thus exposed, can be readily removed by the scoop or graver, as recommended by Mr. Hey, primus, in his excellent work. If, with the probe, it is ascertained that a portion of the cancellated texture has become dead and loose, it is to be removed after dilatation of the external opening. It may frequently be difficult to distinguish in the effused blood, between what is diseased and what is not; it will often be necessary afterwards to cauterise freely the exposed surface, and for this purpose the oxidum hydrargyri rubrum ought generally to be preferred. The slough will soon be thrown off, and healthy granulations fill up the breach. The application of the actual cautery may be by some considered necessary: at one time I employed this remedy very extensively in caries, and occasionally with very good success; I have since, however, been led to change my opinion, and am now inclined to prefer the potential cautery already mentioned. By the application of the red-hot iron, the diseased portion is destroyed effectually, but at the same time the vitality of the surrounding parts is often very much weakened and their power of reparation diminished, so that they are incapable of assuming a sufficient degree of action for throwing off the dead part; their action being increased whilst their power is diminished, they may become affected with caries, and thus, instead of being arrested, the original disease will either be increased, or extensive necrosis may take place. The red oxide of mercury is not calculated to produce such bad effects; it does not spread or insinuate itself into the bony tissue, as liquid caustics are apt to do; and it is sufficiently powerful for complete destruction of the diseased parts. It will be necessary to keep the wound open, by proper dressings, till all the dead portions of bone be discharged, and every part of the parietes of the cavity produce healthy granulations: if the discharge be offensive, its fetor may be corrected by the use of spirituous applications, such as the tinctures of myrrh, opium, or aloes, separately or combined. After healthy granulations have appeared, and the cavity has begun to contract, light dressing is all that is necessary.

In operating on the carpal and tarsal bones for removal of caries, the surgeon must be well acquainted with the connexions and relations of the parts. If one bone is diseased, its removal will be sufficient; if several, the operation becomes more painful and difficult. When one only of the tarsal or carpal bones is almost completely destroyed, and the surfaces of those articulated with it are also more or less affected, it is not sufficient or safe merely to remove the loosely attached portions of the one primarily attacked; the diseased parts of those surrounding it must also be taken away, and it will often be necessary to apply the caustic afterwards. In caries of the distal range of bones, the bases of those supported by them are in general involved, and must also be removed. If one only is diseased, with the base of the metacarpal or metatarsal bone attached to it, the removal of these will be enough, and can be accomplished without difficulty. Some have recommended the total extirpation of a metacarpal or metatarsal bone, leaving the finger or toe appended; but the member, when thus left unsupported, can never become of any service to the patient, and may be productive of much inconvenience; whilst removal of them, along with the diseased bone, renders the operation much more easy of execution. If the whole disease can be extirpated, leaving the surfaces of the surrounding bones covered with healthy cartilage, the use of the caustic is not required, and would be productive of harm; but wherever it is impossible to avoid encroaching on the cancellated texture, such as of the os calcis, which it would be unsafe or imprudent to take away entirely, its use is then indispensable. After the removal of carious bones, the symptoms soon disappear, and the patient obtains a rapid, and often permanent cure. The instruments for these operations, and the method of performing them, will be afterwards mentioned. In conclusion, it may be remarked that the temporary cicatrix of a sore leading to a diseased bone has a very different appearance from the sound scar which is formed after its removal. The former is bluish, soft, on a level with the surrounding parts, and moveable; the latter is depressed, white, and firmly adherent to the bone.

NECROSIS

Death of bone, or Necrosis, is an effect of violent inflammation, particularly of the medullary web, or external injury; a termination of inflammatory action in bone corresponding to sphacelation in the softer tissues. It has been observed, that the bones are not extensively supplied with bloodvessels, and that their natural powers are inferior to those of the softer parts; and from this circumstance the frequency of necrosis can be readily accounted for. The short bones and the heads of the long bones, are more vascular than the flattened bones and the shafts of the long ones. Hence necrosis most frequently occurs in the latter. Necrosis, fortunately, seldom occurs in the heads of the long bones, or penetrates the separation betwixt the cancelli of the shaft and the epiphysis. Bits of dead bone in the articular ends, however, very often lead to disease in the joint. There are in my private collection a few specimens of necrosis, in which matter found its way into the neighbouring joint, leading to disease of the tissues composing it, and rendering amputation necessary for the preservation of the patient’s existence. External injury may produce this disease by causing a violent increase of action, or it may be so severe as at once to deprive part of the bone of its vitality. Destruction of the periosteum, and of the vessels which enter the surface of the bone, frequently gives rise to superficial necrosis or exfoliation. Such a result, however, does not always follow; for we not unfrequently find, when the periosteum has been forcibly torn off, to a considerable extent, by external injury, that the part still retains its vitality. When, however, the bone has been at the same time contused, it is extremely probable that external necrosis may occur. Again, when the periosteum has been removed in the most careful manner possible, exfoliation occasionally takes place. If the exposed bone remain of a brownish hue, it will generally retain its vigour; if, on the other hand, the colour is white, it will most probably be cast off. Necrosis may come on at various periods of life, but is most commonly met with in young subjects, in whom the inflammatory action is allowed to make progress before it is noticed or attended to. It may affect the external or the internal part of a bone, or nearly its whole thickness. The whole of a bone seldom or ever dies in consequence of increased action, and it is not often that the entire thickness of any part of it is found to be necrosed. If the entire thickness dies to a great extent, there is no reproduction; the epiphyses approximate, and the limb, if there is only a single bone, must be lost. A large portion of a bone, or numerous small irregular portions, may die; but still a part of the original shaft remains, and by its vessels reproduction is accomplished. The articulating extremity is very rarely destroyed by this disease. Many writers have talked of death of a bone throughout its whole extent, and, in fact, the term necrosis was originally adopted on this supposition.

The progress of necrosis is, as has been said, similar to that of sphacelation. The affected bone gradually changes its colour, and loses its sensibility; a line of demarcation is formed, and ultimately the dead portion is completely detached from the living. Previous to its separation, the surrounding parts, the portions of bone which are not doomed to perish, have commenced forming new osseous matter, which is secreted in nodules, and from continued deposition soon becomes consolidated. The commencement of the process is well seen in the following sketches from specimens in my collection. The disease, as represented in the two first cuts, was of the most acute kind, and a great part of the shaft of the tibia had perished. This is seen at various points through the sort of cortical deposit of new bone. The new bone, in its turn, secretes a texture similar to itself, whereby the deposit becomes more and more extended, and not unfrequently affords an almost complete encasement to the dead portion, or sequestrum, as represented in the cut on the right-hand side of the page. In general bone dies irregularly, so that the sequestrum presents an uneven surface, and its margins are rough and serrated by numerous

sharp projections, as seen in the one taken from the tibia, and represented here. From the appearance of the dead bone, it was imagined that after its separation, portions of it were removed by absorption; and this opinion was strengthened by the thin exfoliations of the external lamina being found perforated at several points by minute apertures,—worm-eaten, as it was called. These cases of death of inner or medullary shell are irregularly separated, like any other slough; the remaining living outer shell is enlarged by inflammatory action and deposit. But a dead portion of bone, detached from the surrounding parts, is in every respect an extraneous body, and is not, and cannot be, acted on by the absorbents, any more than a piece of metal, wood, or stone. Some have gone so far as to affirm that portions of foreign bodies, ligatures, &c., are absorbed; but this opinion is altogether too absurd to require any contradiction; the knots of ligatures, like portions of glass, or other foreign substance, become surrounded with a dense cyst, and often remain in the body for a long time; so do portions of dead bone separated by the process here described. A series of experiments were made by Mr. Gulliver, in order to put this question at rest, many of which I witnessed and assisted at, and several I also repeated. Setons of bone were inserted and worn for a long time; thin plates of bone were confined on suppurating surfaces; pieces of bone were inserted in the medullary canal of various animals, and kept there for months, and in one instance for more than a year. These foreign bodies were weighed with the greatest care and accuracy before and after they were so exposed to the absorbents, and were found unaltered in any respect. A paper, detailing these experiments, is published in the Medico-Chir. Transactions.

The separation of the dead part from the living is accomplished with greater or less ease, according to the bone which is affected, the state of the constitution, and the general health; in the bones of the superior extremity, this, as well as every other action, proceeds more rapidly than in those of the inferior. It occurs in consequence of absorption of the living part of the bone, which is in close proximity to the dead. The sequestrum, if large, is not pushed off, as some have supposed, by granulations, deposited on the living margin of the bone. A small portion of the inner shell, when completely detached, may sometimes be observed to be extruded from a cloaca by granulations from the living bone. During its progress, matter forms, makes its way to the surface, and is discharged through minute, and often numerous apertures, which afterwards become fistulous. The soft parts are thickened and indurated, and the integuments are red, and sometimes of a livid colour.

Formation of matter upon the bone is occasionally the cause of necrosis, the periosteum being destroyed or separated from its connections by the pressure or insinuation of the pus. I have seen several instances in which it followed neglected erysipelas of the lower extremity.

The matter is in general thick and laudable; at first it is secreted profusely, but afterwards in smaller quantity. The external openings, or papillæ, through which it is discharged, are found to lead to cloacæ, or apertures in the new and living bone, which encase the dead, and through these the dead portions can be discovered by the probe; and it will thus be ascertained whether the sequestrum is fixed or detached: when loose, it can sometimes be moved upward and downward in the cavity. When the shaft of a bone is much affected, the whole limb is enlarged, by the inflammation having extended to a considerable distance above and below the portion about to become necrosed. The unshapely appearance of the limb continues until the sequestra are discharged; for by their presence incited action is still continued, and subsides only after their removal. Some time before any portion of bone has become dead, or begun to be separated, great effusion of new bone has, in general, occurred; thus a preparation has been made for the strengthening of the limb, which, after a considerable portion of the bone has been detached, would otherwise be incapable of supporting the weight of the body. The unnatural bulk of the limb is afterwards much diminished, for the new bone gradually becomes consolidated, and smooth on the surface by the action of the absorbents. Nature seems to construct her substitute after the model of the original, and in some instances but very little change can afterwards be observed in the limb.

In external necrosis, or death of the outer lamella, reparation is chiefly made by the subjacent parts; and this species of necrosis occurs most frequently in the flat bones. In necrosis involving a greater thickness of the bone, the new matter is also furnished by the subjacent parts, which, however, are materially assisted in the process by the living bone, which forms the margins of the void caused by the absorbent process for the detachment of the dead portion. The bony matter is deposited with great activity, and frequently columns of the new deposit cross over the sequestrum, binding it firmly down, and rendering it almost immovable, although it may be completely detached from the living parts.

It has already been stated, that those vessels which ramify within the substance of the periosteum have no share in the reproduction of bone, but plastic matter is effused by the ramifications extending from the membrane to the bone: this effusion becomes organised, and greatly assists in forming the substitute.

It has been formerly remarked, that a limited, and, on after examination, an apparently trifling necrosis of the cancellated structure, may produce the most violent local symptoms; the painful feelings, the discharge, and the thickening of the bone, continue, as long as the cancellated sequestrum remains; severe symptomatic fever is induced, endangering the life of the patient, and often rendering removal of the limb absolutely necessary.

Occasionally abscesses form at a considerable distance from the necrosed part, and terminate in sinuses, which communicate with the diseased bone, and are consequently long and tortuous, so that examination by the probe is rendered difficult. When necrosis is extensive, there is a risk of fracture occurring, if motion of the limb be permitted before a sufficient quantity of matter has been effused, before nature has had sufficient time for the consolidation of her substitute, and consequently before the new bone has come to resemble the old in thickness and cohesion.

Violent inflammatory fever attends the incited action of the vessels of the bone and periosteum which precedes necrosis. But after the abscesses have given way the painful symptoms subside, and the health seldom suffers to any great extent, the system becoming gradually accustomed, as it were, to the new condition of the parts. Hectic supervenes only when the disease is very extensive, and joints become involved. Frequently fresh collections of matter form as each piece of bone approaches the surface. When the effusion of new bone has extended to the neighbourhood of a joint, its motion may be very much impeded, and, from the limb being kept in a state of rest for the cure of the necrosis, anchylosis may even occur.

Treatment.—The means of preventing inflammatory action from running high and ending in death of bone have been already alluded to—abstraction of blood, rest, purgatives, and antimonials. When necrosis has occurred, no interference with the bone is allowable, unless the sequestrum is quite loose, or unless the patient’s health is suffering severely under the discharge and irritation. When the sequestrum can be readily moved about, or when, projecting through the external opening, it can be laid hold of by the fingers or forceps, attempts must be made to remove it. The surgeon ought not, however, to allow it to approach the surface, and project externally, for the natural discharge of the sequestrum is a much more tedious process than the removal of it by art, and by the irritation produced during its spontaneous ejection the inflammatory action is continued, and may prove alarming. Long before it has appeared externally, it must have been completely separated from the living parts, so as to admit of ready extraction by the proper means. When it has been ascertained that the sequestrum is separated, it ought to be laid hold of by forceps, and moved freely upward and downward, so that any slight attachments by which it is connected to the neighbouring parts may be destroyed, whether these be minute filaments which still in some degree retain their vitality, or small portions of newly deposited bone, which are so situated as to prevent the free movement of the sequestrum. In general, no impediment of this nature exists, and the dead bone is easily removed. Before extraction can be accomplished, it is generally necessary to enlarge freely the external opening, in all cases where the dead portion of bone is of considerable size. If, on thus exposing the parts, the sequestrum be found detached, but still firmly bound down by the substitute bone, deposited over it either in one continuous sheet, or in irregular columns, this must be divided by a trephine, a small saw, or cutting pliers, before the sequestrum can be extracted. When a dead portion of bone, of considerable length, is exposed at its centre, whilst its extremities are entangled by the old or substitute bone, the division of the exposed part of sequestrum, by means of the cutting pliers, will often be sufficient for its removal, the cut ends being seized by the forceps, and one half removed after the other; thus the perforation or removal of any portion of the substitute will be rendered unnecessary. The instruments, and especially those for extraction, ought to be very powerful, and suited to the purpose; for in the employment of inefficient means there is much folly and cruelty. Incisions into a necrosed limb are attended with profuse hemorrhage from the enlarged and excited vessels; and in some cases it is with difficulty arrested, in consequence of retraction of the cut ends of the vessels not taking place within the condensed and indurated parts. Pressure, and an elevated position of the part, will generally be found to answer. When necrosis has been extensive, the limb must be carefully supported by the application of splints and bandage, till the process of reparation be completed, in order to prevent fracture of the recently formed substitute. This proceeding is seldom, however, necessary.

The treatment may be summed up in a very few words. Prevent the necrosis, if possible; open abscesses whenever they appear; encourage the patient to move the neighbouring joints; support the strength; remove sequestra when loose, but do not interfere till they are ascertained to be so; give the limb proper support and rest, when a large sequestrum is formed. When fracture has taken place, when the

health has been undermined, or when neighbouring joints have become diseased, amputate, in order to save the life, if it be impossible to save the limb.

It is almost superfluous to remark, that leeching and blistering are worse than useless after necrosis has occurred, however useful they may be in preventing it; and that the adoption of measures to promote the dissolution and absorption of the sequestra are glaringly absurd.

Necrosis, after amputation, was formerly frequent; but in the present improved state of this operation it is so rare as scarcely to demand separate consideration.

Such specimens as here depicted are common enough in the collections of those who have practised the old round-about operation; in fact, it is only by this painful and tedious interference of nature that a tolerable stump is formed in many of these cases. Death of a small portion will sometimes, though very rarely, follow even a very well

performed amputation, if through any mischance the recovery is slow, and wasting discharge takes place with emaciation. It happens sometimes, as when secondary hemorrhage (that is to say, bleeding after the fourth day) has taken place, that the flaps are separated by the coagula, and it may be impossible to bring the parts together and give them due support; then the muscles, wasted and shrunk, may leave the bone a little, but the exfoliation is but very trifling.

The inner shell of bone, as may be seen in the above sketch, perishes more extensively than the outer; and this arises probably from inflammation of the medullary membrane, in consequence of exposure, or, perhaps, from its being sometimes injured by the operator or assistants seizing the bone rudely to steady the stump, in order to facilitate the ligature of the vessels. In experiments on animals, the disturbance and injury of the medullary membrane is followed by internal necrosis, thickening of the outer living shell, and effusion betwixt the periosteum and bone. New bone is also furnished from the medullary canal, as is also shown in the sketch.