Exostosis

“ The denser variety seldom attain any considerable size, but the less compact, growing in the direction of least resistance, often attain such dimensions as to be both unsightly and dangerous. Thus, a frontal exostosis may invade the frontal air sinus and grow into the orbital cavity, obliterating the sinus, interfering greatly with ocular movements, causing protrusion of the globe and even destruction of the eye.
An aural exostosis may block up the external auditory meatus, compress the facial nerve, and lead to the development of a mastoid empyema. ”

“ It follows, however, that splints occur in young animals; that the affection seldom starts in subjects that are ten years of age or older, and that when the exostosis has formed, lameness usually subsides. Anything which will cause undue strain or irritation of the metacarpal bones in young animals, is quite apt to result in a splint being formed. Concussion such as is caused by fast work on hard roads, or work on rough or irregular road surfaces which cause unequal distribution of weight, will cause splint lameness and exostosis follows. ”

“ The distinction between the two varieties of cool and warm, however, may easily be determined by remembering the fact that in most cases the first, or cool, is due to a simple exostosis, while the second is generally connected with disease of the articulation, such as ulceration of the articular surface—a condition which, as we proceed further, will receive our attention when we reach the subject of stringhalt. ”

“ When there is no middle-ear suppuration.
The operation may be performed either (a) through the external meatus or (b) by reflecting the auricle forward by a post-auricular incision.
Through the external meatus. This method is only indicated if the exostosis is situated at the entrance of the meatus and is pedunculated.
A general anæsthetic is given, the patient being in the recumbent position. The surgeon works by reflected light. After the ear has been thoroughly cleansed a large-sized aural speculum is inserted into the meatus and the outlines of the exostosis are defined with a probe. ”

“ Symptoms.—This condition of periostitis is often difficult to determine. The signs of inflammation are so obscure, the swelling of the parts so insignificant, any increase of heat so imperceptible, and the soreness so slight, that even the most acute observer may fail to find the point of its existence, and it is often long after the discovery of the disease itself that its location is positively revealed by the visible presence of the exostosis. ”

“ An animal may travel on a smooth road without giving evidence of any inconvenience, but as soon as a rough and irregular pavement or road surface is reached, will limp. As the subject is driven farther on level streets the lameness may disappear. This intermittent type of lameness may continue until there is developed a large exostosis, or until articular involvement causes so much distress during locomotion that lameness is constant. On the other hand, resolution may occur during the stage of periosteal inflammation, or, an exostosis forms which causes no interference with function. ”

“ In making examinations one must not be deceived by the inconspicuous and seemingly insignificant exostosis which has a broad base. In some cases of this kind, dealers style the condition as "rough in the hock" when as a matter of fact, in some instances, incurable spavin lameness develops.
Treatment.—Many incipient cases of spavin yield to vesication and a protracted period of rest. Results depend primarily upon the nature of the affection. However, in every instance if there is involvement of the tibial tarsal (astragalus) bone, complete recovery is highly improbable. ”

“ When made to step aside in the stall, a spavined horse will flex the affected member abruptly and when weight is taken on the diseased leg, symptoms are evinced of pain, and weight is immediately shifted to the sound limb. This is marked during the incipient stages of spavin. Lameness usually precedes the formation of exostosis, though cases are observed wherein an exostosis is present and no lameness is manifested and no history of the previous existence of lameness is available. ”

“ An aged animal, having recently become very lame, showing a small exostosis on the first phalanx, and with the history given that the osseous deposit was of long standing, should at once lead the veterinarian to seek the source of trouble elsewhere. ”

“ Occasional cases are seen in which Nature has stopped the spread of the disease by walling off the morbid area with exostosis. Such cases should not be adjusted, and the disease may remain latent through a long life. When active the disease proves fatal unless checked, which is possible in the earlier stages, and becomes impossible when the vertebral bodies are too fragile to stand strong adjustments. Discernment in case-taking will avoid any fatalities under adjustment, but by no means all cases of Potts’ Disease are curable. ”

“ The most frequent cause of exostoses appears to be external injury; their progress is slow, attended with slight dull pain, and often accompanied with no inconvenience; their existence can be readily ascertained, a hard and immoveable body being felt where no bone exists in the natural state of parts; but when the tumour projects into an internal cavity, the diagnosis is rendered obscure. Most frequently, they remain stationary, after having attained a certain size, and are productive of little inconvenience, the surrounding parts having accommodated themselves to the new formation. ”

“ When transudations are unhealthy, they may accumulate in serous cavities or in cellular structures, and constitute dropsy. Exudation is the result of inflammation, and the product effused coagulates and becomes the seat of a new growth of tissue. Exosmosis means the passage of fluid from within outward, and is a process constantly taking place in health; while transudation takes place because the blood is watery and the tissues are feeble and permeable, permitting the serum and watery elements of the blood to pass into certain cavities, where they accumulate. ”

“ Exostoses need not to be interfered with, unless they are the source of much inconvenience, either from their size and form, or from their having been detached, and lodged amongst the adjacent soft parts. If loose, they can be removed in the same way as any other extraneous body; if firm, their attachment must be divided by a saw, or by cutting pliers, close to the bone from which they spring. Sometimes, as in the scapula or other flat bone, a portion of the original bony tissue can be cut out along with the new growth, and this renders the chance of any return of disease much less likely. ”

“ The bony exostoses develop in a downward and outward direction. The shape is generally oval. The disease commences in childhood and the bony outgrowths slowly increase in size so that by adult life they attain the size of a walnut. The overlying skin is normal and not attached to the bony tumor. As the tumors grow they tend to interfere with the vision of the patient. This is purely from obstructing the lines of vision as the growth does not usually invade the orbits. The treatment is entirely surgical and consists in chiselling away the bony outgrowth. ”

“ Pus may be thrown off by a mucous membrane, without any actual breach of continuity. Diffuse infiltration of the tissues is the most dangerous form of suppuration.
In this variety of inflammation the exudate is brought into contact with the greatest possible extent of absorbent vessels, for as a surface of a sponge is greater than that of a bag, which would contain it, so the surface of these intercellular spaces is much greater than that of an abscess cavity filled by the same amount of pus. ”

“ It is true that often very distinct layers are separated from the living bone, but these layers are only the product of exfoliation itself. Then in fact the bone dies on the surface; the superficial vessels receive no more blood; this fluid is stopped under the portion deprived of life, the exhalation of the phosphate of lime ceases there, every kind of sanguineous, exhalant and absorbent vessel is destroyed; a slow inflammation, with suppuration, comes on, and fixes the line of demarcation ”

“ When the periostitis and ostitis is the result of a wound, and is complicated by caries or necrosis of the bone, the diseased portion of bone must in every case be laid bare and removed. It so happens that the majority of cases of this kind occur in positions where the diseased bone is easily got at. The lower margin of the os pedis or portions of the wings are commonly the seat of such changes. We meet with the former in cases of pricked foot, and with the latter in severe cases of tread, or as a complication in suppurating corn or in quittor. ”

“ When the infection becomes active, the contents of the cavity are transformed into a greenish-yellow pus from which the staphylococcus can be isolated, and the cavity is lined by a thin film of granulation tissue which erodes the surrounding bone and so causes the abscess to increase in size. If the erosion proceeds uniformly, the cavity is spherical or oval; if it is more active at some points than others, diverticula or tunnels are formed, and one of these may finally erupt through the shell of the bone or into an adjacent joint. ”

“ Bone Diseases and Injuries.—The more specific diseases affecting the bones of the human body are treated under separate headings; in this article inflammation of bone and fractures are dealt with.
Ostitis (ὀστέον, bone) , or inflammation of bone, may be acute or chronic. Acute ostitis is one of the most serious diseases which can be met with in young people. It is due to the cultivation of virulent germs in the delicate growing tissue of the bone and in the marrow. ”

“ The accumulation of an excessive amount of inflammatory exudate may endanger the vitality of the tissues by pressing on the blood vessels to such an extent as to cause stasis, and by concentrating the local action of the toxins. Under such conditions the tension should be relieved and the exudate with its contained toxins removed by making an incision into the inflamed tissues, and applying a suction bell. When the exudate has collected in a synovial cavity, such as a joint or bursa, it may be withdrawn by means of a trocar and cannula. ”

“ Exophthalmos gradually develops, going on later to a complete loss of sight due to compression of the optic nerve by the overgrowth of bone. There may also be interference with the nasal respiration and with the taking of food. In the somewhat less common form of this rare disease the overgrowth of bone affects all the cranial bones as well as those of the face, the senses being lost one by one and death finally resulting from cerebral pressure. There is no treatment other than exposing the overgrown bone, and chipping away pieces, or excising entirely where possible. ”

“ The œsophageal tube is of very simple anatomical construction, and performs an equally simple physiological function; nevertheless, in the ox it is liable to a large number of diseased conditions. These conditions may affect only a circumscribed area of the mucous membrane or the entire extent of the tube. Again, both the muscular and mucous tissues may be affected, as in inflammation of the œsophagus accompanied or followed by contraction, and in the formation of œsophageal abscesses and tumours; or the muscular tissue alone may be affected, as in cases of dilatation. ”

“ In other cases a rough, irregular, infected foreign body may when swallowed penetrate the wall and cause inflammation, necrosis and perforation of the œsophagus.
The symptoms are always very grave, and of rapid development. They consist in local œdematous swelling, sero-sanguineous infiltration at the entrance to the chest, in the pretracheal region and along the jugular furrows.
The pneumo-gastric and inferior laryngeal nerves being compressed, dyspnœa results. If the œsophagus is perforated in the thoracic cavity septic pleurisy at once sets in. ”

“ 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. ”

“ Rupture of the esophagus requires immediate gastrostomy to put the esophagus at rest and supply necessary alimentation. Thoracotomy for drainage is required when the pleural cavity has been involved, not only for pleural secretions, but for the constant and copious esophageal leakage. It is not ordinarily realized how much normal salivary drainage passes down the esophagus. The customary treatment of shock is to be applied. No attempt should be made to remove a foreign body until the traumatic lesions have healed. ”

“ Endoscopically, compression stenosis of the esophagus is manifested by a slit-like crevice which occupies the place of the lumen and which does not open up readily before the advancing tube. The long axis of the slit is almost always at right angles to the compressive mass, if the esophageal wall be uninvolved. The covering mucosa may be normal or it may show signs of chronic inflammation. Malignant compressions are characterized by their hardness when palpated with the tube. Associated pressure on the recurrent laryngeal nerve often makes laryngeal paralysis coexistent. ”