Synovitis

SYNOVITIS (synovitis), an inflammatory disease of the synovial membrane, leading to the formation of exudate in the joint. The causes of this disease may include trauma, acute rheumatism, inflammatory processes in adjacent areas, infectious diseases, and less commonly syphilis and tuberculosis. By course, synovitis can be acute or chronic, and by nature, serous or purulent. Velyaminov divides synovitis into: 1) s. irritativa, 2) s. hyperaemica, 3) s. serosa acuta, s. hydrops acutus. The first form is characterized only by slight hyperemia of the synovial membrane and some swelling with a slight increase in the amount of synovial fluid. With more prolonged and persistent action of the irritant, a small amount of serous exudate forms, and the process from a simple reaction to irritation (s. irritativa) passes into its serous form, characterized by sharp injection, hyperemia, swelling of the synovial membrane, its surface becomes velvety, its villi are enlarged, and a transparent yellowish exudate appears in the cavity, in which float clots and masses of fibrin. Microscopically, during this period, small-cell infiltration and some proliferation of synovial membrane cells are found in the synovial membrane and subsynovial cellular tissue. When transitioning to the chronic form (or when synovitis runs as chronic from the very beginning), the same picture described above is repeated, but with deeper and more persistent changes in the synovial membrane, which becomes greatly thickened, infiltrated under the synovial layer with a tendency to fibrous degeneration and thickening of the fibrous capsule. The purulent form of synovitis manifests as further development of the process, characterized microscopically by hyperemia, impregnation of the synovial membrane with pus cells, extravasates, and the presence of pus-forming rods scattered in the thickness of the synovial membrane. Suppuration can subsequently extend to the joint, the ends of the bones with all the consequences of this complication. Synovitis usually develops in one joint, most often in the knee, then in the elbow, wrist, and ankle, less often in other joints, but can be present simultaneously in many joints, for example, in rheumatism. Acute serous synovitis is characterized by swelling of the joint and pain on palpation due to the accumulation of serous exudate. The joint loses its shape, its contours become smoothed. The temperature is elevated, but can also be normal (for example, in traumatic synovitis). The function of the limb is usually impaired. Treatment of acute serous synovitis consists in providing complete rest to the affected limb, for which it is placed in a splint, and in tight bandaging of the joint. With abundant accumulation of exudate in the joint, puncture is recommended. Often, providing rest to the limb and tight bandaging of the joint is sufficient for the exudate to begin to be absorbed and rapid recovery to occur. In case of incomplete absorption of exudate, lack of rest of the affected limb, the process may recur or pass into a chronic state. Chronic serous synovitis, according to Lexer (Lexer), represents not so much an independent disease, but a consequence and accompanying phenomenon in various pathological processes in the joint. At the beginning of the disease, the symptoms of the disease are not sharply expressed. Rapid fatigue during movement, a feeling of heaviness in the limb, slightly expressed swelling of the joint are sometimes the only complaints of patients. Subsequently, a loose joint, curvature of the limb, and limitation of mobility in the joint may gradually develop. Recognition of chronic synovitis does not present great difficulties, whereas recognition of the underlying disease sometimes becomes difficult. In synovitis of rheumatic origin, the exudate is rarely purely serous; the admixture of leukocytes makes it opalescent and even cloudy (see Rheumatism). Treatment of chronic synovitis, besides local, should be directed against the underlying disease. Serous synovitis, if infected with pus-forming pathogens, can turn into purulent synovitis; in other cases, synovitis from the very beginning has a purulent nature, for example, in acute infectious diseases. Superficial purulent synovitis (synovitis purulenta), or catarrhal inflammation of the synovial membrane, according to Volkmann, represents a relatively benign disease that can end in complete recovery. The symptoms observed in acute synovitis (see above) not only do not decrease in superficial purulent synovitis, but even intensify; temperature remains high, pain becomes sharp, movements in the joint are impossible due to severe pain. The exudate secreted by the synovial membrane is purulent with fibrin flakes. Redness is clearly noticeable on the skin of the joint. The causative agents of pus are most often staphylococcus and streptococcus, less commonly pneumococcus. From the synovial membrane, the purulent process can spread to the suprasynovial cellular tissue, the connective tissue and muscles surrounding the joint, and cause purulent inflammation in them - parasynovitis. In this case, the soft tissues of the joint involved in the purulent process become doughy swollen, and the area of inflammation expands. The skin takes on a glossy appearance. Pain on palpation is severe, but not as violent as in suppuration of the joint. Diagnosis of purulent synovitis is not difficult; the above symptoms are quite characteristic; difficulty may arise in differentiating it from gonorrheal joint lesions, which have similar symptoms of the disease (see Arthritis, gonorrheal arthritis). Treatment of purulent synovitis consists in emptying the abscess either by puncture or by incision of the joint and draining it. In the treatment of parasynovitis, wide opening of the abscess and good drainage are required. The affected limb must be given rest, for which it should be placed in a splint. As a result of purulent parasynovitis, wrinkling and scarring of connective tissue develop, which can subsequently lead to impaired movement in the joint. Correct and timely treatment of synovitis and parasynovitis in all their forms can lead to complete restoration of joint function.