LOCALIZED ARTHRITIS DEFORMANS.
The localized variety of arthritis deformans differs from the mul tiple in several remarkable respects.
In the first place it affects men more frequently than women; sec ondly, it attacks the large joints rather than the small, the most cen tral rather than the most peripheral.
It is met with in its most typical form as the hip-joint disease of elderly men, and it was from the post-mortem examination of cases of this affection, the morbus cox senilis, or chronic rheumatic ar thritis of Adams, that the complete picture of the morbid anatomy of arthritis deformaus was originally drawn.
Very many cases of this affection have their origin in some in jury, slight or severe, to the parts in the neighborhood of the hip joint, and it is to this variety that one looks for the best examples of such traumatic origin.
The disease shows little tendency to spread, but the immunity of other joints, although the rule, is by no means constant, and it is not very uncommon to meet with Heberden's nodes in association with the hip-joint disease, or a slighter involvement of the opposite hip, with or without some associated affection of the lumbar spine.
The earliest symptom is pain and stiffness on movement. The pain is of a gnawing character, and like the pain of the acute hip disease of children often extends down the thigh to the knee.
Sciatica is the affection with which morbus core senilis is most liable to be confused, but the difference in the situation of the pain of sciatica, the local tenderness over the inflamed nerve trunks, and the extension of the pain right down to the foot, usually deprives the diagnosis of any serious difficulty.
When doubt arises the patient may be subjected to the following tests : When a sufferer from arthritis deformans in the hip-joint is requested to cross the affected leg over the sound one, while in the sitting posture, he experiences much difficulty in doing so and is usually obliged to raise the thigh with his hands and lift it over the other one. Again when the patient stands upon the sound leg and attempts to rotate the foot of the affected side, there is found to be considerable limitation of the rotatory movement at the hip-joint. A further test is to place the patient in the recumbent position and to deliver a sharp push upon the sole of the foot. This proceeding will cause pain in a diseased hip-joint, but not in the case of sciatica unless from the jailing of the limb.
• Flattening of the buttock and wasting of the thigh of the affected side is a prominent sign of hip-joint disease, as distinguished I'D .lit the wasting of the limb its it whole sometimes seen in cases of sciatica of some standing. The knee jerk on the affected side is as a rule markedly increased. In a word, the wasting conforms to the usual type of arthritic muscular atrophy.
As the disease progresses the abrasion and absorption of the head of the femur is apt to lead to a considerable degree of shortening of the limb, and in some cases the shortening is extreme.
Occasionally cysts of enormous size are developed in connection with chronic arthritis deformaus of the hip-joint, and these are some times situated so far from the joint itself as to have no obvious con nection with it. Similar cysts are sometimes met with in association with other joints besides the hip, such as the shoulder, elbow, and knee.
Morrant Baker," who first described these cysts, holds that the synovial fluid which has accumulated in the cavity of the joint, hav ing reached a certain degree of tension, makes its way out of the joint, in the direction of least resistance, either by the channel through which a normal bursa communicates with the joint. or by forming a hernia of the synovial membrane. Ultimately, if the ten sion continues to increase, the fluid escapes from its sac and fates in a cavity the boundaries of which are formed by the and other tissues of the part.
It is not always possible to make out the presence of a communi cation between the cyst and the joint cavity during life, but it is cer tainly unsafe to argue from the failure to detect any such communi cation that none exists.
Next to the hip the shoulder and knee are the joints most fre quently attacked by the localized form of arthritis deformans. One shoulder or both may suffer, and as in the case of the hip affection the lumbar spine may be involved in the disease, so the affection may be accompanied by spondylitis of the cervical or spine.
The movements of the joint are greatly limited, and in the stages there is cracking, in the later grating on movement. There :s seldom any effusion into the joint, but enlargement due to osteophyte formation may be made out when the disease has existed for seine time, and, as has been already mentioned, the mechanism of the ar ticulation may be reversed, the glenoid cavity being converted into a convex boss, the head of the humerus into a cup. The adjacent muscles including the deltoid undergo conspicuous atrophy, and such arthritic atrophy of the muscles of the shoulder must be distinguished from progressive muscular atrophy. This distinction is usually -a matter of no difficulty, the affection of the joint being revealed by crackling and by limitation of movement, which, even in the earlier stages of the disease, is conspicuously seen when the attempt is made to raise the hand to the head.
There is a peculiar type also common in men in which the disease is limited to the carpo-metacarpal joints of both thumbs. The en largement of these joints is easily made out, and crackling and creak ing on movement are readily detected. In the cases which I have seen, the onset of the disease has usually appeared to be referable to some occupation in which the thumb is much used, so that the joints in question are subjected to strain.