Congenital Defects of Bones. Various congenital deformities of the limbs occur because of interference in various ways with the proper and normal formation of these cartilaginous masses. If, for any reason, the cause of which in most cases is not clear, any of these cartilaginous masses fail to be formed in the embryonic tissues, naturally no ossification can occur, and in such cases there may be a partial or complete lack of development of the corresponding bone. The amount of this congenital deformity may vary from the absence of an entire foot, to the absence of one or several digits, or one or more phalanges.

The deformities produced by such a failure to deposit the cartilaginous base of the bones are very numerous, and in some cases lead to great deformity and loss of function. This lack or increase of the reformation in cartilage, results in most extraordinary deformities.

No special type of deformity merits special attention; the condition in each case must be decided by inspection and X-ray examination.

In many of these cases, especially where the lesion affects the digits, the capability of the individual is but little impaired, whilst in other cases, where bones are absent, marked deformity and impairment of function may occur. Some of the cases, notably webbed toes, are comparatively easily corrected; other cases however, offer little chance of sufficient cosmetic or functional gain to make a surgical operation necessary or desirable.

Atrophy of Bone. Various causes may lead to atrophy of bone. The method by which atrophy is brought about is peculiar, and is due to the action of special giant cells, called osteoclasts. Wherever extensive atrophy of bone takes place, microscopic inspection shows such giant cells lying closely adjacent to the trabeculae of the bone which is being resorbed, and the trabeculae in that immediate vicinity slowly disappear under the action of these giant cells. Their action is very similar to the action of giant cells in the soft tissues about absorbable foreign bodies. This process is called lacunar resorption.

In old people the amount of absorption oftentimes is very great; the process is then termed senile atrophy. It may be marked in the skull and in the long bones, and in many cases of fracture of the neck of the femur, a moderate amount of lacunar resorption precedes the fracture which results from slight violence. In certain cases this resorptive process in old people is extreme, and leads to great fragility of the bones, with repeated fractures from slight violence, which under ordinary circumstances, would cause no injury at all.

A mere lack of use of bones may also lead to a certain amount of atrophy from lacunar resorption. This may be seen after amputations, where the stump of bone which is left from the amputation slowly undergoes lacunar resorption and sometimes a marked diminution in size. The same thing may also be seen in the bones of people who for long periods of time have been deprived of the use of their limbs, either by the application of apparatus around fractures, or by disuse for other reasons.

Lacunar resorption also occasionally follows lesions of the central nervous system, part of the atrophy being due to disuse of the limbs from the paralysis, and part of it also being dependent in some indirect way upon the nerve lesion.

Atrophy of bone also may be brought about by pressure. It is to be remembered that the bone, as a matter of fact, is not a perfectly rigid material, but that processes of new formation and resorption are constantly taking place, even under normal conditions. If, for any reason, bone is put under constant pressure, a certain amount of readjustment of the bony constituents takes place in order to adapt the bone to its altered condition. The most striking example of this sort of atrophy is perhaps the Chinese ladies’ feet, where the bones, being bent into an abnormal position, beginning early in childhood, ultimately show enormous deformity and an entire rearrangement of the trabeculae of the bone. The same thing also may be seen occasionally after pressure and deformity from contracture of muscles or from the pressure of scars. This process, which ordinarily leads to loss of function, in a certain limited number of cases aids function, for whilst certain fractures of the joints may lend to deformity of the articular facets of those joints, by absorption of certain portions and new formation in others, a readjustment of the joint surface may take place, so that a marked increase of function may occur.

A certain amount of atrophy also may be brought about by the pressure and development of tumors.

Hypertrophy of Bone. In many cases new growth of bony tissue is due to the new formation of periosteal bone, and is an expression of an attempt at repair of one or the other of the numerous destructive processes. In other cases true hypertrophy of the bone, with no connection with any reparative process, may occur.

A notable example of this is seen in the growth of bone which sometimes occurs after amputation, especially in young people. The increased size of the bones which is seen in many definite diseases will be mentioned under the proper headings.

Caries and Necrosis. Various pathologic processes produce destruction of bone. The destructive process may cause the death of large areas of the affected bone at once, and in that case, a large fragment of necrotic bone may remain in situ and still maintain its contour. Destruction of bone of this sort is described by the clinical term necrosis.

Other processes cause a gradual molecular softening and destruction of bone, which ultimately may be very extensive, but at no time is there present any appreciable large mass of bone. Destruction of this sort is described by the clinical term caries.

As a means of differentiating clinical conditions, the use of these two words is desirable. As a clinical term, necrosis usually means destruction by pyogenic infection, and caries, destruction by the gradual extension of a tuberculous process. This clinical distinction, however, is not an exact one, because destruction of large areas of bone, described as necrosis, is occasionally brought about by syphilitic infection, and rarely by tuberculosis, whilst molecular destruction of the bone is brought about by a considerable variety of processes, the chief of which, it is true, is tuberculous infection, but actinomycosis and syphilis may both lead to the gradual disintegration of the bone, without the formation of large necrotic masses of bone.

The presence of necrotic bone connected with the surface of sinuses, from which comes a discharge of pus, should always lead to the consideration of tuberculosis, actinomycosis, and syphilis. The presence of large sequestra of bone should immediately suggest the presence of osteomyelitis or of syphilis.

Treatment.The details of the treatment of the various forms of destructive processes in bone will be found under their special headings, chiefly under osteomyelitis and tuberculosis.

In all cases of caries it is desirable to remove completely the softened areas in the bone. This may be done by curettment and drainage, or by excision of the entire bone, or series of bones, in certain cases, or rarely by amputation.

The difficulty in all these cases is to recognize the exact limits of the carious process. It must be borne in mind that at the time of operation upon carious bones the field of vision of the surgeon is almost always limited; moreover, the bleeding which always takes place from the bone-marrow in such cases, also obscures the field, and even if these two causes were not present, it is frequently extremely difficult, by naked-eye examination to determine the exact limits of the destructive process. As a general rule, it can be said that the carious area is at least a quarter of an inch wider than appears upon visual inspection.

In cases of necrosis with large bone defects, the difficult thing is to cause a growth of the bone toward the central cavity after removal of the sequestrum. The various methods applicable to such cavities are mentioned in detail under “Osteomyelitis.”

PERIOSTITIS

Acute Periostitis. The older text books always laid great stress upon the occurrence of an acute infectious inflammation of the periosteum. Acute suppurating periostitis alone does not occur, and most of the cases which have been described as such are really mild cases of superficial osteomyelitis, with abscess formation beneath the periosteum, and possibly slight inflammation of the periosteum itself.

These cases ordinarily lead to only a slight destruction of the outer layer of the cortical bone.

Symptoms. These are the same as in acute osteomyelitis, except in a very much milder form. There is usually a rise of temperature, oftentimes with a chill, with circumscribed tenderness over some portion of the shaft of one of the long bones.

Treatment. Incision over such an area shows an elevated periosteum, with a small, localized abscess beneath it, with bare, white, somewhat vascular bone cortex. Incision alone in most cases suffices to cure the disease, although if the process has extended sufficiently deep to cause a superficial necrosis of the outer layer of the cortex, removal of a small sliver of necrotic bone may be necessary.

Chronic Periostitis. A long-continued and chronic irritation of the periosteum, sufficient to cause a proliferation of the osteogenetic cells of the periosteum, is common in a great many diseases. A chronic thickening of the periosteum with a new formation of bone, is seen frequently after traumatism, blows or contusions; sometimes after the occurrence of superficial abscess of the soft tissues in the immediate vicinity of the shaft of the long bone, described as chronic ulcer of the surface of the tibia; or after certain infectious diseases, notably syphilis. It also may occur after various other local infections. In such cases the thickening of the periosteum ordinarily is pretty sharply localized.

A general thickening over the periosteum, and over several or many of the bones of the body, also occurs in the disease known as toxic osteoperiostitis ossificans, seen in diseases with long continued suppuration. It also is common after syphilitic disease, either congenital or acquired.

Symptoms. The symptoms of chronic periostitis with new formation of bone are invariable. In a certain number of cases there is a constant, heavy, dull pain, at the point of thickening, with at times more or less acute exacerbation; at other times the lesion is associated with no pain whatever, and the patient’s attention is first called to the disease by the presence of the enlargement of bone. Recognition of the condition may depend upon X-ray examinations for indefinite pains in or over the bone.

Chronic periostitis is not really a disease itself, but a manifestation of the reaction of the periosteum to some irritant.

Treatment of the condition depends, first of all, upon a recognition of the cause and a removal of the cause, when possible. In many cases, especially those in which no pain is present, nothing in the way of therapeutic measures can be done.

The chronic thickening of the periosteum, seen in many definite bone diseases, will be mentioned under those diseases.

Osteomyelitis. Infectious osteomyelitis is acute suppuration of the bone, always due to the infection of the bone marrow by pyogenic microorganisms. The process is essentially like the process seen in furuncle, and begins in the marrow of the alveolar spaces, which communicate freely with each other, but are enclosed by a dense shell of cortical bone. Hence the process may quickly at first involve the entire marrow of an infected bone, because the products of bacterial infection are retained in this dense shell, while the primary focus can only be reached by extensive bone operation.

Most cases are due to the staphylococcus pyogenes aureus and a few to the streptococcus. Typhoid bacilli may cause suppuration. The infecting organism is present in pure culture but sometimes a mixed infection occurs, and such cases are said to be severe.

In cases of chronic osteomyelitis with open sinuses and exposed bone, a great variety of organisms, pathologic and saprophytic, may be present. Hence infectious osteomyelitis is not a specific disease, but is acute inflammation of bone that may be produced by any one of a variety of pathogenic organisms, or by a mixed infection.

Any pyogenic organism which can be carried in the blood may be deposited in the bone and produce suppuration. Some of these organisms may settle by preference in the bone marrow, others beneath the periosteum, or in the joint.

Certain general causes favor the occurrence of osteomyelitis. Children are chiefly affected and it occurs in boys about three times as often as in girls. Acute osteomyelitis frequently occurs after injuries of moderate severity, because such injuries may lower resistance of the bones and make them unusually susceptible to pyogenic infection. One of the commonest causes is the infection of a compound fracture, and before the days of asepsis, such cases were very frequently fatal. Under modern methods the infection, when it does occur, is generally slight, although the destruction of bone may greatly delay healing and may lead to the formation of small sequestra and indurating sinuses. Infection of a similar sort may occur subsequent to amputation.

Osteomyelitis nearly always begins in the diaphysis of the long bones, usually near the epiphyseal line. This is an important point, clinically, because tuberculosis practically begins in the epiphysis. In rare cases, however, osteomyelitis begins in the epiphysis, and so may simulate tuberculosis. The femur and tibia are the bones most frequently attacked, but no bone is exempt. Usually only one bone is affected, but cases of multiple bone infections are not rare.

The primary area of infection is always in the bone marrow. The bony trabeculae and the cortex are destroyed only secondarily. The process nearly always begins in the diaphysis, but then may extend into the epiphysis and produce suppuration of the joint. Once the organisms have gained access to the marrow, they produce a toxin which causes necrosis of the adjacent marrow cells, and this necrosis may extend over a very considerable portion of the bone before marked infiltration with leucocytes occurs. The infection usually extends quite early through the dense cortex by way of the Haversian canals, and produces an inflammatory exudation and suppuration between the periosteum and the outer layer of the cortex, which is designated subperiosteal abscess.

Such an abscess may strip the periosteum from the bone over very extensive areas. The infection may then extend to the adjacent soft parts, muscles and subcutaneous tissue, and form an abscess outside the periosteum.

If, from spontaneous opening of the abscess or from operation, a fatal result is avoided, the infective process may be limited and the process of repair may begin.

As a rule, a portion of the infected marrow and cortex become completely necrotic, and the lime-bearing portion of the bone persists as a more or less extensive sequestrum.

The periosteum in the early stages may be separated from the bone by a collection of pus, and in such cases it appears as a thin fibrous membrane beneath the muscles, separated from the bone by the abscess cavity.

Secondary changes occur in the soft tissues surrounding the seat of an acute suppuration of bone. During the acute stage there may be a definite abscess of the soft parts, with an infiltration which simulates phlegmonous inflammation, or, by rupture of the abscess, various sinuses may be formed leading down to the necrotic foreign body. In long continued cases the skin and subcutaneous tissues become thickened by the formation of scar tissue, due to the presence of the involucrum and the persistence of sinuses, and by thickening of the soft tissues, an affected limb may for years be nearly twice its normal size.

Symptoms. The disease usually begins with a sharp onset, the first symptom being a sudden localized pain in the vicinity of the epiphyseal line, or in the shaft of some one of the long bones. This pain is extremely intense, and in typical cases is most excruciating.

Motion of the joints at this time is not painful, but the pain produced by percussing the bone, even lightly, may be intense. An extremely valuable diagnostic point is continued gentle pressure at some point over the shaft of the bone at a distance from the point of greatest constant pain.

Usually, at a very early period, there appears swelling of the soft parts about the bone. This swelling, at first, is neither hot nor red, but soon becomes edematous, red, and shows pitting on pressure, and at that time may simulate acute phlegmon.

In some cases the adjacent joint early becomes tender, hot and swollen, and this may occur even when there is no real extension of the infectious process to the joint itself. If extension does occur to the joint, swelling, tenderness, and pain on motion become more intense. The temperature usually is elevated to a considerable degree—103°F. or 104°F.—and usually the pulse is greatly accelerated. Evidence of constitutional disturbance and absorption of infectious material occur early. The tongue is dry, coated and tremulous; the face is drawn and flushed. Delirium of a mild type is a very common symptom, and in some cases this delirium may persist for a considerable length of time after the bone has been drained. Abscess of the soft parts may give deep or superficial fluctuation. Sinuses may appear. The leucocyte count is usually very high—25000 to 35000,and chiefly of a polynuclear type.

Such a clinical picture is perfectly distinct, and it is difficult to overlook typical cases, especially after the fluctuation in the soft parts has occurred. The diagnosis of early cases, however, is sometimes very difficult, and even in the hands of experienced men, who have the lesion in mind, is frequently impossible. Even in severe cases, occasionally the pain itself is not severe for several days, when there may come a sudden exacerbation of symptoms.

In the chronic stages of osteomyelitis the symptoms are usually characteristic. The limb is enlarged, the enlargement being partly due to thickening of the soft tissues, but chiefly to the formation of the involucrum. Usually running down to the sequestrum, are enormous sinuses, from which comes a foul, purulent discharge. On passing a probe, dead bone can be felt at the bottom of the sinuses. It must be borne in mind, however, that in a great many cases, after attacks of osteomyelitis of moderate severity, small localized abscesses are formed in the shaft of the long bones, with no sinus communicating with the surface. An abscess of this description, as has already been stated, is always surrounded by a wall of dense bonelike cortical bone.

Such an abscess may persist for years with no symptoms beyond a moderate enlargement of the shaft of the bone at the point of abscess, and the enlargement may be so slight that it is not recognized by the patient. In other cases the entire shaft may be enlarged, but the bone may not be tender. In most cases, however, such a localized abscess sooner or later gives rise to recurring attacks of pain, which, as a rule, are extremely violent. The intervals between such attacks may vary from days to weeks, or to months, or even to years. The attacks of pain may come on, apparently, perfectly spontaneously. Associated with these attacks of pain, the bone over the abscess usually is exceedingly tender to touch. With the attacks of pain may come a rise of temperature, or in some cases, there may be no disturbance of the general condition. This kind of abscess may be of small size, no larger than a pea, or may involve a great portion of the shaft of the bone; in such abscesses no definite sequestrum may ever form.

The recognition of such conditions depends upon recurrent attacks of violent pain over circumscribed areas of bone, with or without constitutional disturbance, and nearly always with extreme local tenderness.

Treatment. In the acute stage there is suppuration of the marrow, more or less extended throughout the shaft, with often a subperiosteal abscess and perhaps abscess of the soft parts.

The indications are the same as in any other acute suppuration; the pus must be evacuated and the bone cavity drained. This demands not only an incision into the soft parts, but an opening into the shaft of the bone. If a piece of necrotic bone is present, it should be removed.

In the chronic stage there is usually an old necrotic shaft perforated by sinuses, and often freely movable, inclosed by a shell of dense periosteal bone. The sequestrum must be removed, but the bony defect fails to heal, and for months persists as a filthy, discharging cavity, with the constant danger of secondary infection and phlegmon, or erysipelatous inflammation. The healing of this cavity is very difficult and requires a very long time.

Many methods have been tried for the filling of these bone cavities with blood clot, iodoform and oil of sesame, but they have not been successful, because it is almost impossible to render such cavities absolutely aseptic.

Tuberculosis of Bone. Tuberculosis of bone is always dependent upon infection of the marrow of bone by the tubercule bacillus. This germ obtains entrance to the bone marrow and causes the formation of miliary tubercules which arise from the proliferation of the connective tissue of the marrow around the primary tubercule. Other secondary tubercules are formed by extension of the tubercule bacillus. The centres of these tubercules become caseous, and, by fusion of adjacent caseous areas, also cause softening in the bone marrow.

The tuberculous process, as a rule, begins in the epiphysis in the long bones, and may affect any of the bones.

Symptoms. In cases of tuberculous disease confined to the bones alone, the first symptom usually is pain, which ordinarily is not severe and has a gradual onset. Oftentimes, at first on palpation, no difference in the shape of the bone can be detected.

Toes affected by a tuberculous process, slowly enlarge at first without heat or pain; ultimately the skin becomes thickened, and reddened, and the digit is painful to pressure or motion. Oftentimes the skin is perforated at one or more points by sinuses lined with tuberculous granulations, through which caseous pus is discharged.

The diagnosis in these cases always lies between tuberculosis, actinomycosis, syphilis, and osteomyelitis, and exact determination of the origin of the cause oftentimes can be made only by inoculating animals with a discharge from the sinus, or by detection of pyogenic organisms, or of the miliary tubercule, the histologic unit of tuberculosis, or by detecting the peculiar yellow bodies seen in actinomycosis.

Treatment. From a clinical point of view tuberculosis of bone should be considered in the same category as malignant disease, and the indications for treatment in all cases of tuberculous bone disease are the same as in malignant disease; which is, complete removal of the infected area, whenever it is possible.

In some cases the mere opening and curetting of tuberculous areas in bone is oftentimes enough to set up sufficient reaction in the bone and in the surrounding tissues, to put an end to the tuberculous process. Complete resection of bones may at times be avoided by this treatment.

In addition to the local treatment of opening, curetting and drainage, or the complete excision of the bone, the greatest care should be employed in the management of the general hygiene of the patient, including feeding and fresh air. Often removal to a climate which is unfavorable to the development of tuberculosis in general, is also extremely desirable.

Syphilis of Bone. The lesions produced in bones by syphilitic infection may be congenital or acquired, and, as in other syphilitic lesions, the manifestations may be protean.

Most children with congenital syphilis, show an irregularity of the epiphyseal line, which results in the latter becoming markedly toothed, instead of constituting a straight line across the bone, at right angles to the long axis of the shaft.

Besides the irregularity of the epiphyseal line, three other changes are seen in the bones of syphilitic infection. The most common lesion is one which affects the periosteum and leads to the formation of periosteal bone. This periosteal formation may occur either in congenital or in acquired syphilis, and it may affect one or many bones. In some cases there is an enormous thickening of the epiphysis of the bones, and as a result of the epiphyseal thickening, secondary changes in the joints occur, so that the thickening of bones and the changes in the facets of the joints, suggest fracture or dislocation. In other cases, the thickening affects only the shafts of the long bones, generally of the leg or arm, although no bones are exempt. In some cases, both in the congenital and acquired forms, there may be marked proliferation of the endosteum of the bone, with or without thickening of the periosteum, although thickening of the periosteum usually is present. This process, as a rule, affects one bone in its entirety, and most commonly affects the bones of the lower leg, notably the tibia. As a result of these changes the bones are enlarged and thickened, and in some cases, from endosteal thickening, the marrow canal is very largely or entirely obliterated. In some cases true gummata of the bone are formed. These gummata may appear in the spongy portion of the bone, sometimes in the shaft, or in the epiphysis. They also appear to be formed in the lower layers of the periosteum and lead to circumscribed nodular thickenings on the surface of the bone.

Symptoms. These vary with the different pathologic conditions present. The periosteal thickening may occur at any time of life over any bone of the body.

The presence of circumscribed periosteal thickening of bone in itself should always lead to the suspicion of the presence of syphilis.

Pain, as a rule, is only very slight, and the diagnosis depends upon the history and the detection of other syphilitic lesions.

The cases in which there is both endosteal and periosteal thickening, occur chiefly in children and are of a congenital nature.

The physical symptoms are very characteristic. The bone usually affected is the tibia, which is enlarged to a most marked degree, and often shows a pronounced bowing forward, similar to the bowing and thickening of the tibia seen in osteitis deformans. The bone is extremely dense and obviously heavier than normal. The bones are moderately tender to pressure, but have nothing like the extreme tenderness noted on pressure in osteomyelitic bones.

In cases of gummata of bones the symptoms vary. In some cases the gummata are on the surface of the bone, especially the sternum, and at times on the long bones. In such cases there appear a softening and reddening of the skin about the affected area, which remains indolent for a long time.

If such an area opens spontaneously, or is opened by incision, the contents are seen to be composed of a yellow, rather gelatinous material, quite like the caseous material from a tuberculous abscess.

Treatment. In most cases the regular anti-syphilitic treatment is indicated. In cases of periosteal thickening, the results vary with the time at which the treatment is begun. In the early cases, a thorough anti-syphilitic treatment may lead, after a varying length of time, to complete disappearance of the newly formed periosteal bone. On the other hand, if the periosteal process has lasted for a long time and the bone has become densely cortical, although anti-syphilitic treatment may lead to a diminution of the localized pain, the dense bone does not disappear. In cases of combined endosteal and periosteal thickening, the pain usually disappears under anti-syphilitic treatment but the changes in the bone persist.

Osteomalacia is an acquired disease which causes marked softening and changes in the bones. The disease begins irregularly and often progresses with or without remissions. The progress is more marked during pregnancy. The first sign is pain in the bones, which is increased by pressure, and this is especially true of pressure over the ribs. There are also muscular cramps and contractures.

Osteitis Deformans. (Paget’s Disease). This is a chronic disease of the bones and may affect one or more bones of the body. The onset is insidious, and before actual deformity occurs, long indefinite pains in the legs may have existed, with occasional tender points over the bone.

The bony changes are first noticed in the bones of the legs and are most marked in the tibia, femur and fibula. As a result of structural changes, these bones become bowed, while their internal trabecular structure is altered.

The extent of the affection in the bones of the legs varies a great deal and usually is not symmetric. The lower extremities are bowed outward, and also are usually bent forward, the curves being due to changes in the femur and the lower leg.

Treatment. In the absence of any knowledge as to the cause of the disease, the treatment of osteitis deformans must be largely symptomatic. Certain drugs have been recommended; among these are iodide of potash and arsenic. Most such patients are in poor general condition, and effective feeding often gives marked relief of the symptoms from which they are suffering.

For severe pain, counterirritants are valuable, especially the actual cautery. Massage is of use in some cases for improving the general condition.

Tumors of Bone. All the primary tumors of bone are of the connective tissue group, but various secondary tumors of epithelial origin may occur.

Osseous tumors may arise from the periosteum or from the marrow. If they arise from the periosteum they may extend early to the adjacent soft tissues and involve and destroy them. If the tumor arises in the marrow, it is for a long while cut off from the adjacent soft tissues by the thick cortex, and about the extending medullary tumor may also come a reactive proliferation by the periosteum, so that as the tumor extends it still may, for a long time, be surrounded by a shell of bone which prevents infection of the soft parts. After a time, however, the reactive periosteum shell usually becomes perforated at one or more points, and then the medullary tumor extends to the adjacent tissues. The cause of these tumors is absolutely unknown.

Fibromata are not very common tumors of bone. They arise generally from the periosteum and are most common about the face, and are rarely seen in the long bones. Many of these tumors are closely allied to some of the fibrous forms of sarcoma, and it is often difficult to distinguish them histologically.

Chondromata are fairly common tumors of bone. They may appear externally to the cortex, or sometimes they grow in the medullary canal. They may arise directly from the marrow, probably from remnants of the provisional cartilage cells. They also appear frequently to arise from the epiphyseal line.

Chondromata appear generally as multiple masses, nodular in shape, and are frequently seen on the lower leg, about the knee joint. They usually are painless, firm and hard, and not tender to pressure.

Treatment consists in removal by operation.

Osteomata are bony tumors which generally arise by growth of the periosteum, and form solid bony masses external to the cortex of the bone, when they are called exostoses.

The density of the bone composing the tumor varies a great deal, some being very hard and ivorylike, while others are like the cellular marrow of the long bones.

Osteomata may be surrounded by a layer of fibrous periosteum or, in certain cases, beneath the periosteum appears a layer of cartilage producing the so-called exostosis cartilaginea. The latter formation is the one which is most common in the vicinity of the epiphyseal line of the long bones, notably of the leg.

Osteomata form circumscribed hard nodular masses of bony consistency, and are usually painless. They may cause interference with function from their size, especially when they appear in close connection with a joint.

Treatment is complete and thorough removal.

Sarcomata are the most common tumors of bone; they are malignant, and when removed, tend to recur, either locally or by metastasis, in different parts of the body. The metastases usually are distributed by the circulation.

These tumors may arise from the marrow, but generally in the epiphysis of the bone and extend to the shaft only at a later stage of their development. As the tumor advances, it causes a softening and an absorption of the original cellular marrow until it approaches the periosteum.

In many cases the periosteum, as about any form of foreign body, then begins to proliferate and forms a shell of periosteal bone surrounding the tumor. In that way the shell of the bone oftentimes becomes very much enlarged before there is any extension of the process through the shell to the adjacent tissue. By destruction of the marrow and of the cortex, great softening of the bone may occur so that spontaneous fractures not infrequently are seen.

Other sarcomata arise from the periosteum, and usually originate from one side of the bone, although occasionally they entirely surround the bone. In the periosteal sarcomata, a new formation of bone is common and the bone is frequently arranged in a radical way, giving a most remarkable picture on the X-ray plate.

Myeloma is a very rare malignant tumor of bone. Such tumors always appear only in connection with bone, are usually multiple, and are of the same type as other lymphoid tumors.

The cells of such tumors resemble very closely the type of plasma cell. These cells are arranged in masses without an intercellular substance, and the tumors are closely allied to the malignant lymphomata. The cases are always associated with albuminuria.

Symptoms. The chief symptoms of malignant tumors are swelling and pain, both of which oftentimes are extreme. The swelling may be spherical or spindle shaped.

Extension to the joints may not occur for a great length of time. In many cases X-ray examination is the most reliable method of detecting the character of the bony change.

Treatment of all sarcomata is early and complete removal. This means in nearly all cases, amputation of the affected bone, and it is important that the amputation should be of the entire bone through the joint between the bone and the body, rather than amputation of the bone in continuity. The reason for this is, that even in sarcomata, which have not extended to the soft parts, very frequently there have occurred metastases of tumor-cells throughout the blood sinuses of the affected bone, often times at a distance of several inches from the site of the original primary tumor.

Carcinomata. Cancer of bone always is secondary to cancer in some epithelial organ. The infection may take place by direct extension through the blood or the lymphatics.

In cases of metastatic invasions of bone, spontaneous fractures oftentimes are the first symptom which calls attention to the fact that metastases have occurred.

Treatment. As in other malignant tumors, the indication is for absolute and radical removal whenever possible. Unfortunately, this very seldom can be done, because at the time the bone has become affected by extension to any great degree, radical operation is impossible. Many times, however, extensive operations must be undertaken for the removal of bone.

Cysts of Bone are rare lesions which practically always occur secondary to other lesions. They may occur as the result of the degeneration and softening of bone sarcomata. Some of the cases of bone cysts undoubtedly represent the entire destruction of sarcomatous processes. Occasionally echinococcus cysts of bone occur.

Treatment. Cysts of bone due to softening of the centre of sarcomatous tumors, like sarcomata themselves, are to be treated by complete removal, best usually by amputation. Cysts of bone not due to the presence of sarcomatous tissue, should be opened and drained in some cases. Cysts due to the presence of echinococcus, should be opened and drained, with the removal of every vestige of the echinococcus.