SECONDARY ARTHRITIS DEFORMANS.
It is often very difficult to be sine whether or no the chronic ar ticular lesions which follow as the sequelm of various acute forms of arthritis are actually of the natu] l of arthritis deformans or merely simulate that disease. There cinnot, I think, he any doubt that in some instances such changes, although they may closely simulate arthritis deformans, are due to thickening of the structures around the joint and not to the implication of the cartilages and bones; but on the other hand there are eases in which true arthritis deformans apparently takes its origin in joints which have been damaged by diseases of other kinds, and spreads from these to articulations which have previously escaped.
The difficulties encountered in attempting to arrive at a just con clusion are especially great when the chronic articular lesions occur as the sequels of an attack of acute rheumatism.
In the first place doubt may arise as to whether the original at tack was actually one of acute or subacute rheumatism and not rather the more acute form of arthritis deformans, which in its earlier stages may, as has been already pointed out in a previous section, be easily mistaken for such an attack. The development of the signs of endocarditis or of pericarditis will, of course, afford evidence of the nature of the primary disease, seeing that such lesions are not met with in cases of genuine arthritis deformans; but it must be re membered that arthritis deformans is most likely to occur in persons who have reached a period of life when true rheumatism has far less tendency to implicate the heart than it has in earlier life. Other diagnostic signs will be the tendency of the joints first involved to recover quickly while new ones are involved, profuse sweating, and the tendency of the joint affection to yield quickly to the salicylic drugs. On the other hand persistency of the lesions and the affection of joints such as the temporo-maxillary articulations, which are little prone to acute rheumatism, speak strongly for the diagnosis of ar thritis deformans.
Even when the rheumatic nature of the primary attack is beyond question, the diagnosis of the true nature of the secondary chronic arthritis may present even greater difficulties. There occasionally
results from acute rheumatism a condition first described by Jaccoud and named by him "ikumatisme ,filmeux," which in its superficial as pects closely resembles arthritis deformans, and which is attended by fusiform enlargement of joints, and by similar muscular deformi ties; but in which no lesions of the bones or cartilages are found if the case comes to post-mortem examination. • In many instances the deformities are permanent, but when the acute attack has been recent, the fusiform swellings may improve re markably in time, to the surprise of the medical attendant who has not anticipated any so favorable result. I have met with several cases in which this has been the course of events.
There are certainly many cases which cannot be referred to this class, and in which, although the rheumatic nature of the origina1 attack is beyond doubt, as time goes on the characteristic osteophytic outgrowths and other features of arthritis deformaus make their appearance.
It is quite possible that in some such cases the damage done to the joints by the acute rheumatism is not really the starting-point of the deforming lesions, but that rather the subsequent arthritis de formaus stands in the same relation to the febrile attacks as it some times does to other febrile disorders, such as influenza, which do not implicate the joints.
The following was one of the most typical examples of post-rheu matic arthritis deformans that have come under my notice: The patient, a woman, aged 34 years, had first suffered from rheumatic fever when 11 years old, and had had two subsequent at tacks at the ages of 18 and 24. Since then she had suffered from three attacks of moderate severity, since the last of which she had never been free from articular pains and had noticed enlargement of the finger-joints, which presented the typical appearance of arthritis deformans. There was marked ulnar deflexion of the fingers.