116 Pollnow found osteo-chondritis in 35 out of 50 syphilitic foetuses (Der Hydrops Sanguinolentes foetus, Berlin, 1874, quoted by Hill and Cooper, op. cit., p. 352).
117 Bumstead and Taylor, op. cit., p. 767.
The swelling is found to consist of a ring or collar which more or less completely surrounds the bone, is apt to be smooth rather than irregular, and when two bones situated near to each other are simultaneously affected may conjoin them. This condition persists during the first stage of pathologists, and passes with greater or less rapidity into the second stage, in which the swelling, the cell-proliferation, reaches its height. This may take, in cases uninfluenced by treatment, several weeks or even months. Under the use of mercurials and iodide of potassium they usually subside rapidly. During this second stage, however, owing to the proximity of the swellings to the joints, a moderate amount of synovitis is often present. This affects chiefly the elbow and the knee, but may appear in any joint. It is also readily influenced by specific treatment and well-regulated pressure.
When the third stage is reached, or that of the formation of granulation-tissue, with degenerative changes of the cartilages and of the bones themselves, deformity often becomes more marked. There are unnatural curves or angles in the bones, with more or less complete separation at the point of junction. Where many bones are affected in this way, the resulting deformity is extreme and the patient may be absolutely powerless, a condition of pseudo-paralysis supervening in which the limbs lie motionless or swing about like the arms or legs of a doll when the child is carried.
When the swelling does not undergo absorption, the superjacent tissues sometimes become involved, abscesses form and make their appearance externally, extensive necrosis of the shaft of the affected bone takes place, and the little patient usually dies of hectic, pyæmia, or exhaustion. When the cranial bones are involved, the disease is apt to limit itself chiefly to the stage of osteophytic formation, the immovability of the bones probably favoring the organization of the new cell-growth rather than the production in it of inflammatory changes. The growths are met with chiefly in older children than those affected with the form of osteo-chondritis just described; they affect the periphery of the liver, and are found most usually around the anterior fontanel, and later on the parietal and frontal eminences. The sutures are sometimes completely soldered together.118 The osteophytes vary in thickness from a quarter of an inch to an inch, or are even larger.119
118 In a case reported by Barlow it was not possible at the autopsy to discover the point of union (Path. Transactions, 1879, p. 339).
119 These conditions may all result in a child the subject of acquired syphilis, but are apt to be milder, to involve fewer bones, and to yield more readily to treatment. This would of course be expected, inasmuch as the same difference in favor of the acquired form, as compared with that which is inherited, extends to all the lesions. As Diday succinctly expresses it: "In the one case the poison vitiates only the elements of nutrition; in the other it vitiates at the same time those of formation and those of nutrition." It would exceed the limits of the present article to describe acquired syphilis in children.
The most important differential diagnosis to be made in these cases is between the rachitis of young children and the form of syphilis in question. Much difference of opinion still exists as to the relation between these diseases, syphilis being claimed, on the one hand, as having in the majority of cases a definite causative influence, while, on the other, the existence of this relation is denied. When we come to contrast the pathology of the two diseases, we can readily understand why they should be confounded, the minuter changes which occur being essentially the same—viz. cell-proliferation and accumulation, with subsequent inflammatory changes, associated with irregular deposits of lime salts.
Compare, for example, the description of the pathology of bone diseases in inherited syphilis already given (pp. [287], [288]) with the following terse summary of the changes which take place in rickets in cases where no suspicion of syphilis exists, either ancestral or acquired: "The changes are more distinctly noticed at the epiphyses than in the diaphyses. Instead of the regular stages and distinct boundaries observed in the normal development of bone, there is a singular disorderly commingling of the exaggerated cartilage-proliferation and transition substance, with calcification. The cartilage-cells, stimulated to excessive multiplication, are transformed, some into bone-corpuscles, some into medullary cells, and others into connective-tissue forms. The same process is in active operation in the deep periosteal layers, the material accumulating to such a degree as to add much to the thickness of the shaft."120
120 Agnew's Surgery, vol. i. p. 1030.