Hydrarthrosis

Hydrarthrosis, or dropsy of a joint, is characterized by a serous effusion into the joint cavity and is noted as a symptom in a number of, primarily chronic, arthritides. Serous effusion is also noted in certain forms of acutely progressing arthritides, primarily so-called "rheumatic" ones. Serous effusion does not always serve as a manifestation of an inflammatory state of the joint. Often it indicates only that there is a certain irritant (even a mechanical one) for the synovial membrane, which responds to the irritation with an effusion. Thus, in the presence of a loose body or a torn meniscus pinching between the articular surfaces, an effusion may periodically appear. However, more often, chronic effusions are associated with inflammatory diseases of the joint, among which the first place should be given to chronic infectious polyarthritis ("rheumatism" of the joints), syphilitic synovitis, and tuberculous dropsy. Depending on the etiological factor, dropsy may be observed simultaneously in several joints (as in polyarthritis infectiosa chronica) or manifest in isolation, more often in the knee joint, as in tuberculosis. The exudate, upon culturing, almost always proves to be sterile. To exclude tuberculosis, inoculation of the exudate into a guinea pig is necessary. In those cases where serous effusion appears under the influence of a mechanical irritant in a capsule that is still little changed, such an exudate can quickly be reabsorbed with appropriate therapy. Conversely, where serious changes have already occurred in the synovial layer of the capsule (thickening, villous growths, etc.), as, for example, in chronic infectious polyarthritis, the effusion persists very stubbornly, stretching the capsule and producing secondary changes in it. In the treatment of hydrarthrosis, attention must be directed to the primary affliction. In an acute case of so-called "rheumatic polyarthritis," rest for the joint and specific therapy with salicylates are sufficient, followed later by dry-air baths and massage. In the chronic period, all types of physiotherapy are indicated. In particularly stubborn cases, chronic dropsy disappears only after synovectomy. In tuberculous dropsy, treatment should be directed along the lines of treatment for tuberculous arthritis (see Tuberculosis). For serous effusion of syphilitic origin, specific therapy is indicated.