CHAPTER XXXII
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SURGICAL DISEASES OF THE OSSEOUS SYSTEM.
At the outset of a study of surgical diseases of the osseous system it is necessary to emphasize a fact which students and young practitioners are liable to forget, namely, that bone, even the densest, is _a tissue_, and that as such it is liable to infection, suppuration, gangrene, etc., just as is any other tissue; that all infectious processes are identical in general character, their gross manifestations varying only by virtue of the peculiar characteristics of the tissue in which the infection occurs. Bone is vascular, and even that exceedingly hard variety, which is met with in the petrous portion of the temporal, or the ivory exostosis, has sufficient connection with the vascular system to permit of its proper nutrition. The firmest and hardest bone will bleed when divided or injured, and any tissue which will thus bleed can react injuriously to various irritants.
All bone-marrow begins as red marrow, with 1 or 2 per cent. of fat, and ends by becoming yellow, with 60 or 70 per cent. of fat, and whether this change shall take place suddenly or rapidly depends upon diverse conditions. Many years ago it was claimed by Bourgery that bone is simply a large cavernous arrangement where stagnation of the blood current favors the deposition of fat. Fatty alteration progresses from periphery to centre, and the bones of the hands and feet undergo fatty alterations before those of the trunk and pelvis. In other words, the truncal skeleton remains as “red bone” longer than the balance of the osseous system, and he whose sternum has become a “yellow bone” should have reached a ripe old age. In long bones distal extremities first become fatty. Individual peculiarities seem to govern these changes. Thus the neck of the femur will sometimes be fatty and friable at the fortieth year, or reasonably firm and still red at the eightieth. This fatty condition is not to be confounded with true osteoporosis or rarefaction in bone, though it is often associated with it. When the two conditions are combined we have _osteoporosis adiposa_. Into this condition immobilized limbs pass more easily than those which are used. Their weeks have been equal to years of ordinary inactivity. Red bone seems to be too highly vascular to be a favorite site for tubercle, and distinctly yellow bone too non-vascular. Consequently bone tuberculosis is less often seen at the extremes of life. White bone, as those who make anatomical preparations call it, is most favorable for tuberculous infection on account of its minimum contents of blood and fat. These bones come from phthisical subjects.
ACUTE OSTEOMYELITIS.
This condition was never accurately recognized until described by Chassaignac, in 1853, and even he missed many of its distinctive features, although he gave to it a most descriptive name, “typhus of the limbs.”
=Pathology.=--The disease is a distinctly infectious process, limited sometimes to the bone-marrow and internal portion of the bone, sometimes apparently involving every particle of the osseous structure. Its onset is sudden, its manifestations acute and serious, and its ravages, when not promptly checked, most extensive. The following more or less distinct varieties may be distinguished:
The staphylococcus;
The streptococcus;
The pneumococcus;
The tuberculous;
Miscellaneous infections, including the colon bacillus, the typhoid bacillus, etc.
It is known that the virulence of cocci growing under pressure is thereby much enhanced; hence the extreme rapidity of some of these disease processes may be thereby better explained.
[Illustration: PLATE XXXV
Acute Osteomyelitis, showing Purulent Foci and Accompanying Disturbance (Kocher.)]
[Illustration: FIG. 223
Typhoid infection of bone; focus in rib. (Lexer.)]
The mechanism of the infection and the lesions produced by the organism are essentially similar, and may be described together. These consist of rapid _thrombosis_, _coagulation necrosis_, and _suppuration_, along with the local destruction incident thereto, and with unlimited possibilities in the way of _auto-intoxication_ from the local lesions and from the disturbance of the general economy and interference with excretion. Every severe case is accompanied by more or less of general septic intoxication, presumably from the ptomaine produced by the bacteria, while in many instances, particularly those where the bacteria at fault seem extremely virulent, the intoxication is overwhelming and the course a rapidly fatal one. Death has been known to follow within thirty-six hours after the first symptom of an acute osteomyelitis. For the average case three more or less distinct stages can usually be distinguished: first, a period of _purulent infiltration_, with the formation of local foci in the bone-marrow and speedy secondary involvement of the periosteum and synovial membrane; second, a period of _sequestration or formation of a sequestratrum_ inside of an abscess cavity; third, the _stage of repair_.
=First Stage.=--During this period there occurs violent inflammatory infiltration, localized areas becoming at first hyperemic, then infiltrated with hemorrhagic exudate, whose rapidity of production will indicate the intensity of the infection. Often at the same time are found enlargement of the spleen and hemorrhagic exudations in distant serous cavities, such as the pleura and pericardium. The locally infected areas of bone-marrow break down into collections of pus, which spread either toward the epiphyseal line or else along the Haversian canals toward the periosteum, which becomes both infiltrated and loosened. The loosening is particularly marked about the shafts rather than the joint ends, while, as a rule, that end of the bone toward which the nutrient artery is directed is the one whose epiphyses are first loosened. Nevertheless about the knee it would seem as though the lower end of the femur and upper end of the tibia are the particularly predisposed localities.
In many instances obliteration of nutrient vessels and thrombosis are early features. The area of separation of the periosteum is usually an index of the extent of deep destruction. From the periosteum the infection may extend toward the covering of the soft parts, in which case there may be a parosteal abscess, or it may perforate toward the joint cavity, leading quickly to pyarthrosis and destruction of joint structures. It would appear in children, particularly, that the epiphyseal cartilage often forms a barrier to the advancement of the lesion in the direction of the joint, and thus it happens that we have acute necrosis of the shaft of a long bone, with perforation through the periosteum at both of its ends. In adults this takes place less often, the joint ends being often primarily involved. Softening and separation of cartilages are usually secondary to the other processes. It is possible even to have the primary infection in the joint end proper, and extension therefrom to the epiphyses permitting of epiphyseal separation and extrusion of this fragment as a sequestrum. This separation occurs in many instances rapidly and before the attendant is aware of what has happened.
=Second Stage.=--The second stage includes, coincidently with the occurrence of suppuration, the proliferation of considerable granulation tissue, by which more or less protection is afforded; also, when time is afforded, the rapid formation of new bone, whose effect is to wall off the scene of conflict and death from the surrounding tissue, by which event prognosis, so far as the patient’s life is concerned, is improved. Intra-osseous abscesses may quickly coalesce, and the result may be one long tubular abscess extending through the shaft. At other times both bone-marrow and the cancellous tissue are bathed in pus, while if the periosteum have been totally separated the consequence will be a sequestrum whose dimensions correspond with those of the shaft. When periosteum is not loosened the necrosis will probably be central and more or less circumscribed. (See Plate XXXV.)
=Third Stage.=--The third stage is the period of efforts at spontaneous repair. There is a natural effort toward elimination of the sequestrum by the process of softening or liquefaction in the direction of least resistance. This process may extend over months, when surgical relief has been delayed, and may be accompanied by so much other disturbance as to completely ruin a bone or limb for further use. In neglected cases several sinuses may lead down toward the central sequestrum. On the other hand, once this sequestrum of eliminated an extraordinary amount of activity is usually displayed in the direction of repair (Fig. 224).
[Illustration: FIG. 224
Acute necrosis of tibia, with formation of cloacæ for affording opportunity for escape of sequestra. Illustrating also the extensive openings which necrotomy may necessitate. (Lexer.)]
=Symptoms.=--In a general way the signs and symptoms of acute infectious lesions in bone are strikingly similar, and are significant when construed aright. Patients complain usually first of _exhaustion_, followed by _pain_, which may become agonizing. This is often accompanied by an introductory _chill_ with high fever, after which the general character of the disease assumes the typhoid aspect. Evening temperature may rise high and be followed by some morning remission. The spleen is usually enlarged, the primæ viæ disturbed, and often we have to do with a fetid diarrhea. In the young the sensorium is early affected and children soon become delirious. The _pain_, at first vague, quickly focuses in the particular bone or bones most involved, and as it increases in intensity there is a significant _tenderness_. Ordinarily there appear early reddening and swelling of the affected parts. With all these evidences there is also a characteristic muscle spasm, by which certain posture signs will be produced, varying with the bone involved. Pain is always intensified by the slightest degree of disturbance. In consequence the limbs (for it is the limbs which are usually involved) are contracted, and every effort to overcome the contractures is followed by aggravated pain. The more acute the pain the more vivid the external evidences of inflammation and the edema of the parts, especially below and about the lesion. Thus it may happen that within forty-eight hours there may be swelling and edema of the
## part involved, which should be regarded as pathognomonic.
A little later, superadded to the other signs of inflammation, there is _fluctuation_ if parosteal abscesses have formed, or possibly the evidences of _epiphyseal loosening_ or complete separation. When the disease is primary in an epiphysis the corresponding joint will be early involved, and the joint symptoms will assume the type of an acute purulent synovitis, but with more pain. It is probable that under few circumstances is complaint of pain more serious or aggravating than in cases of acute osteomyelitis of the fulminating type.
So far only local symptoms have been described. To these there should be added the list of those pertaining to _thrombosis_ and _metastatic infection_, with their septic and disastrous consequences. The disease is frequently so acute and rapid that even within the first day or two not only are added extensive thrombosis in and along the bones, with rapid purulent degeneration and thrombi, but soon that even more serious general condition to which these lesions so easily give rise--_i. e._, unmistakable _pyemia_.
The general symptoms are common to the disease, no matter what bone be involved. Local symptoms will change in accordance with their location. While not so common, the flat bones, like the pelvis, cranium, and sternum, may be involved in active manifestations of this disease. The same is true even of the vertebræ, but, as a rule, it is in the long bones of the extremities that its ravages are most frequently seen.
=Prognosis.=--The prognosis depends upon the early recognition of the disease and prompt surgical relief. There is perhaps no disease less amenable to purely medicinal treatment, and if bones are to be saved in their entirety early and free incision is called for. Consequently when the case is seen late it almost invariably entails necrosis, with more or less disturbance of function, or possibly such a serious condition as to call for amputation. The fulminant cases when not early recognized and promptly operated often prove fatal, and death has been known to follow within thirty-six hours after the onset of the first symptom, the fatal result being due to overwhelming septic infection, with thrombosis, etc. Almost every case, however, if seen sufficiently early can be saved.
=Complications.=--The complications are to be divided into the constitutional and the local. The former refer rather to the spread of septic infection and its more or less disastrous and remote ravages. Metastatic infections may produce serious or fatal complications, while, when less acute, important functions may suffer a serious impairment. Among the local sequels are to be considered mainly the results of destruction of bone tissue and neighboring joint structures. When the disease occurs in young and rapidly growing children partial or complete arrest of development in the bone involved is not infrequent. This may lead to inequalities in length of the femora or humeri. It may lead also to compensatory hypertrophy of bone, with perhaps considerable distortion during subsequent growth.
An entirely distinct consequence of osteomyelitis is _bone abscess_, in which the acuteness of symptoms has long since subsided, but in which a distinct local focus remains.
=Etiology.=--The disease is an infection from the beginning, but the source of the infection is not always easy to trace. Two distinct causes seem to conspire to produce the majority of these bone infections--_microörganisms_ of more than ordinary virulence, and a _predisposing condition_ of the system, due sometimes to constitutional weakness or inherited taint, or to the results of exposure and fatigue. The causes of suppuration have been discussed in